Dual-color live imaging unveils stepwise organization of multiple basal body arrays by cytoskeletons.

For mucociliary clearance of pathogens, tracheal multiciliated epithelial cells (MCCs) organize coordinated beating of cilia, which originate from basal bodies (BBs) with basal feet (BFs) on one side. To clarify the self-organizing mechanism of coordinated intracellular BB-arrays composed of a well-ordered BB-alignment and unidirectional BB-orientation, determined by the direction of BB to BF, we generated double transgenic mice with GFP-centrin2-labeled BBs and mRuby3-Cep128-labeled BFs for long-term, high-resolution, dual-color live-cell imaging in primary-cultured tracheal MCCs. At early timepoints of MCC differentiation, BB-orientation and BB-local alignment antecedently coordinated in an apical microtubule-dependent manner. Later during MCC differentiation, fluctuations in BB-orientation were restricted, and locally aligned BB-arrays were further coordinated to align across the entire cell (BB-global alignment), mainly in an apical intermediate-sized filament-lattice-dependent manner. Thus, the high coordination of the BB-array was established for efficient mucociliary clearance as the primary defense against pathogen infection, identifying apical cytoskeletons as potential therapeutic targets.

Ablation of p57+ Quiescent Cancer Stem Cells Suppresses Recurrence after Chemotherapy of Intestinal Tumors.

Quiescent cancer stem cells (CSC) are resistant to conventional anticancer treatments and have been shown to contribute to disease relapse after therapy in some cancer types. The identification and characterization of quiescent CSCs could facilitate the development of strategies to target this cell population and block recurrence. Here, we established a syngeneic orthotopic transplantation model in mice based on intestinal cancer organoids to profile quiescent CSCs. Single-cell transcriptomic analysis of the primary tumors formed in vivo revealed that conventional Lgr5high intestinal CSCs comprise both actively and slowly cycling subpopulations, the latter of which specifically expresses the cyclin-dependent kinase inhibitor p57. Tumorigenicity assays and lineage tracing experiments showed that the quiescent p57+ CSCs contribute in only a limited manner to steady-state tumor growth but they are chemotherapy resistant and drive posttherapeutic cancer recurrence. Ablation of p57+ CSCs suppressed intestinal tumor regrowth after chemotherapy. Together, these results shed light on the heterogeneity of intestinal CSCs and reveal p57+ CSCs as a promising therapeutic target for malignant intestinal cancer. SIGNIFICANCE: A quiescent p57+ subpopulation of intestinal CSCs is resistant to chemotherapy and can be targeted to effectively suppress the recurrence of intestinal cancer.

Life Expectancy of Patients With Severe Aortic Stenosis in Relation to Age and Surgical Risk Score.

BACKGROUND: There is a paucity of data regarding shorter life expectancy after aortic valve replacement (AVR) in patients with severe aortic stenosis (AS). METHODS: Among 3815 patients with severe AS enrolled in the CURRENT AS (Contemporary outcomes after sURgery and medical tREatmeNT in patients with severe Aortic Stenosis) registry, there were 1469 patients (initial AVR: n = 647; conservative strategy: n = 822) with low surgical risk, 1642 patients (initial AVR: n = 433; conservative strategy: n = 1209) with intermediate surgical risk, and 704 patients (initial AVR: n = 117; conservative strategy: n = 587) with high surgical risk. Among 1163 patients who actually underwent surgical AVR as the initial strategy, patients were divided into 4 groups according to age <65 years (n = 185), 65 to 74 (n = 394), 75 to 80 (n = 345), and >80 (n = 239). The expected survival of the general Japanese population was obtained from the Statistics Bureau of Japan. The surgical risk was estimated using The Society of Thoracic Surgery (STS) score. RESULTS: The median follow-up was 3.7 years. The cumulative incidences of all-cause death were significantly lower in the initial AVR strategy than in the initial conservative strategy across the 3 STS groups. Shorter life expectancy after surgical AVR was seen especially in younger patients. The observed mortality in low-risk patients was comparable to the expected mortality across all the age-groups, while intermediate-risk patients aged <75 years, and high-risk patients across all age-groups had higher mortality compared with the expected mortality. CONCLUSIONS: The risk stratification according to age and STS score might be useful to estimate shorter life expectancy after AVR, and these findings have implications for decision making in the choice of surgical or transcatheter AVR.

Peripheral Venous Pressure Measurements to Evaluate Congestion in Heart Failure.

BACKGROUND: Accurate bedside assessment of congestion in the management of patients with heart failure remains challenging. As a continuous conduit of circulating fluid, systemic congestion represented by high right atrial pressure (RAP) may be reflected by peripheral venous pressure (PVP). We evaluated the reliability of PVP measurements for assessing congestion beyond conventional clinical assessments. METHODS AND RESULTS: We performed conventional congestion assessments and PVP measurements in 95 patients undergoing pulmonary artery catheterization. PVP was measured via the 22-gauge peripheral venous access placed in the upper extremity. The median RAP and PVP was 7 (interquartile range [IQR]: 5-11) mmHg and 9 (IQR: 7-12) mmHg, respectively, with a mean bias of 1.8 ± 2.6 mmHg. PVP exhibited a strong linear correlation with RAP (Spearman R = 0.81; P < 0.001). PVP demonstrated greater discriminatory power for both RAP ≤ 8 mmHg (area under the curve [AUC]: 0.91 [95% confidence interval: 0.85-0.97]; sensitivity: 75%; specificity: 87%) and RAP > 12 mmHg (AUC: 0.98 [0.95-1.00]; sensitivity: 88%; specificity: 95%) than edema, jugular venous pressure, pulmonary congestion on chest radiograph, B-type natriuretic peptide levels, and inferior vena cava diameter. CONCLUSIONS: PVP measured via peripheral venous access strongly correlates with invasively obtained RAP. PVP measurements may improve current bedside assessments of congestion.

Modifiers of the Risk of Diabetes for Long-Term Outcomes After Coronary Revascularization: CREDO-Kyoto PCI/CABG Registry.

Background: Diabetes is a well-known risk factor for adverse outcomes after coronary revascularization. Objectives: This study sought to determine high-risk subgroups in whom the excess risks of diabetes relative to nondiabetes are particularly prominent and thus may benefit from more aggressive interventions. Methods: The study population consisted of 39,427 patients (diabetes: n = 15,561; nondiabetes: n = 23,866) who underwent first percutaneous coronary intervention (n = 33,144) or coronary artery bypass graft (n = 6,283) in the pooled CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Graft) registry. The primary outcome measure was major adverse cardiovascular and cerebral endpoints (MACCE), which was defined as a composite of all-cause death, myocardial infarction, and stroke. Results: With median follow-up of 5.6 years, diabetes was associated with significantly higher adjusted risks for MACCE. The excess adjusted risks of diabetes relative to nondiabetes for MACCE increased with younger age (≤64 years: adjusted HR: 1.30; 95% CI: 1.19-1.41; P < 0.001; 64-73 years: adjusted HR: 1.24; 95% CI: 1.16-1.33; P < 0.001; >73 years: adjusted HR: 1.17; 95% CI: 1.10-1.23; P < 0.001; P interaction < 0.001), mainly driven by greater excess adjusted mortality risk of diabetes relative to nondiabetes in younger tertile. No significant interaction was observed between adjusted risk of diabetes relative to nondiabetes for MACCE and other subgroups such as sex, mode of revascularization, and clinical presentation of acute myocardial infarction. Conclusions: The excess risk of diabetes relative to nondiabetes for MACCE was profound in the younger population. This observation suggests more aggressive interventions for secondary prevention in patients with diabetes might be particularly relevant in younger patients.

Percutaneous coronary intervention using new-generation drug-eluting stents versus coronary arterial bypass grafting in stable patients with multi-vessel coronary artery disease: From the CREDO-Kyoto PCI/CABG registry Cohort-3.

AIMS: There is a scarcity of studies comparing percutaneous coronary intervention (PCI) using new-generation drug-eluting stents (DES) with coronary artery bypass grafting (CABG) in patients with multi-vessel coronary artery disease. METHODS AND RESULTS: The CREDO-Kyoto PCI/CABG registry Cohort-3 enrolled 14927 consecutive patients who underwent first coronary revascularization with PCI or isolated CABG between January 2011 and December 2013. The current study population consisted of 2464 patients who underwent multi-vessel coronary revascularization including revascularization of left anterior descending coronary artery (LAD) either with PCI using new-generation DES (N = 1565), or with CABG (N = 899). Patients in the PCI group were older and more often had severe frailty, but had less complex coronary anatomy, and less complete revascularization than those in the CABG group. Cumulative 5-year incidence of a composite of all-cause death, myocardial infarction or stroke was not significantly different between the 2 groups (25.0% versus 21.5%, P = 0.15). However, after adjusting confounders, the excess risk of PCI relative to CABG turned to be significant for the composite endpoint (HR 1.27, 95%CI 1.04-1.55, P = 0.02). PCI as compared with CABG was associated with comparable adjusted risk for all-cause death (HR 1.22, 95%CI 0.96-1.55, P = 0.11), and stroke (HR 1.17, 95%CI 0.79-1.73, P = 0.44), but with excess adjusted risk for myocardial infarction (HR 1.58, 95%CI 1.05-2.39, P = 0.03), and any coronary revascularization (HR 2.66, 95%CI 2.06-3.43, P<0.0001). CONCLUSIONS: In this observational study, PCI with new-generation DES as compared with CABG was associated with excess long-term risk for major cardiovascular events in patients who underwent multi-vessel coronary revascularization including LAD.

Association of peripheral venous pressure with adverse post-discharge outcomes in patients with acute heart failure: a prospective cohort study.

AIMS: Congestion is the major cause of hospitalization for heart failure (HF). Traditional bedside assessment of congestion is limited by insufficient accuracy. Peripheral venous pressure (PVP) has recently been shown to accurately predict central venous congestion. We examined the association between PVP before discharge and post-discharge outcomes in hospitalized patients with acute HF. METHODS AND RESULTS: Bedside PVP measurement at the forearm vein and traditional clinical examination were performed in 239 patients. The association with the primary composite endpoint of cardiovascular death or HF hospitalization and the incremental prognostic value beyond the established HF risk score was examined. The PVP correlated with peripheral oedema, jugular venous pressure, and inferior vena cava diameter, but not with brain-type natriuretic peptide. The 1-year incidence of the primary outcome measure in the first, second, and third tertiles of PVP was 21.4, 29.9, and 40.7%, respectively (log-rank P = 0.017). The adjusted hazard ratio of PVP per 1 mmHg increase for the 1-year outcome was 1.08 [95% confidence interval (1.03-1.14), P = 0.004]. When added onto the Meta-Analysis Global Group in Chronic HF risk score, PVP significantly increased the area under the receiver-operating characteristic curve for predicting the outcome [from 0.63 (0.56-0.71) to 0.70 (0.62-0.77), P = 0.02), while traditional assessments did not. The addition of PVP also yielded significant net reclassification improvement [0.46 (0.19-0.74), P < 0.001]. CONCLUSION: The PVP at discharge correlated with prognosis. The results warrant further investigation to evaluate the clinical application of PVP measurement in the care of HF. TRIAL REGISTRATION NUMBER: UMIN000034279.

A case of gastrointestinal stromal tumor metastasized to the left ventricular myocardium.

BACKGROUND: Gastrointestinal stromal tumors (GISTs), which are the most common soft tissue tumors of the gastrointestinal tract, originate from Cajal interneurons. The main metastatic sites of GISTs are the liver and intra-abdominal cavity, and metastasis to the heart is rare. CASE PRESENTATION: The patient was a 78-year-old man who was diagnosed with a rectal GIST 20 years previously. Since then, he had undergone repeated operations for metastasis. A follow-up thoracoabdominal computed tomography scan 4 months prior to the operation revealed GIST metastasis to the left ventricular myocardium. The patient wanted the tumor removed and consequently underwent an operation. The surgical findings showed a 3-cm × 3-cm mass in the lateral wall of the left ventricle. The mass was resected from the left ventricular wall in the shape of a tear drop. The left ventricular cavity was closed with a 4-0 polypropylene mattress suture and continuous suture. Postoperative histopathological findings showed nodular tumor growth consisting of bundles of spindle-shaped cells in the myocardium. The margins were negative. Immunostaining showed c-KIT (CD17) positivity and CD34 positivity, consistent with GIST metastasis. CONCLUSIONS: This case involved GIST metastasis to the heart muscle, which has rarely been reported worldwide.

Spatiotemporal reprogramming of differentiated cells underlies regeneration and neoplasia in the intestinal epithelium.

Although the mammalian intestinal epithelium manifests robust regenerative capacity after various cytotoxic injuries, the underlying mechanism has remained unclear. Here we identify the cyclin-dependent kinase inhibitor p57 as a specific marker for a quiescent cell population located around the +4 position of intestinal crypts. Lineage tracing reveals that the p57+ cells serve as enteroendocrine/tuft cell precursors under normal conditions but dedifferentiate and act as facultative stem cells to support regeneration after injury. Single-cell transcriptomics analysis shows that the p57+ cells undergo a dynamic reprogramming process after injury that is characterized by fetal-like conversion and metaplasia-like transformation. Population-level analysis also detects such spatiotemporal reprogramming widely in other differentiated cell types. In intestinal adenoma, p57+ cells manifest homeostatic stem cell activity, in the context of constitutively activated spatiotemporal reprogramming. Our results highlight a pronounced plasticity of the intestinal epithelium that supports maintenance of tissue integrity in normal and neoplastic contexts.

Ezrin knockdown reduces procaterol-stimulated ciliary beating without morphological changes in mouse airway cilia.

Mucociliary clearance, which is conducted by beating cilia cooperating with the surface mucous layer, is a major host defense mechanism of the airway epithelium. Ezrin, a crosslinker between membrane proteins and the actin cytoskeleton, is located in microvilli and around the basal bodies in airway ciliary cells. It is also likely that ezrin plays an important role in apical localization of ß2 adrenergic receptor (ß2AR) in airway ciliary cells. Here, we studied the physiological roles of ezrin by using trachea and airway epithelial cells prepared from ezrin-knockdown (Vil2kd/kd) mice. The trachea and airway ciliary cells of Vil2kd/kd mice presented a normal morphology and basal body orientation, suggesting that ezrin is not directly involved in development and planar cell polarity of cilia. Procaterol stimulates ciliary beating (frequency and amplitude) via ß2AR in the airway ciliary cells. In the Vil2kd/kd mice, airway ciliary beating stimulated with procaterol was partly inhibited due to the impairment of cell surface expression of ß2AR. These results suggest that ezrin regulates the beating of airway ciliary cells by promoting the apical surface localization of ß2AR. This article has an associated First Person interview with the first author of the paper.

Concomitant Mitral Regurgitation in Severe Aortic Stenosis　- A Report From the CURRENT AS Registry.

BACKGROUND: The clinical significance of concomitant mitral regurgitation (MR) has not been well addressed in patients with severe aortic stenosis (AS).Methods and Results:We analyzed 3,815 patients from a retrospective multicenter registry of severe AS in Japan (CURRENT AS registry). We compared the clinical outcomes between patients with moderate/severe MR and with none/mild MR according to the initial treatment strategy (initial aortic valve replacement [AVR] or conservative strategy). The primary outcome measure was a composite of aortic valve-related death or heart failure hospitalization. At baseline, moderate/severe MR was present in 227/1,197 (19%) patients with initial AVR strategy and in 536/2,618 (20%) patients with a conservative strategy. The crude cumulative 5-year incidence of the primary outcome measure was significantly higher in patients with moderate/severe MR than in those with none/mild MR, regardless of the initial treatment strategy (25.2% vs. 14.4%, P<0.001 in the initial AVR strategy, and 63.3% vs. 40.7%, P<0.001 in the conservative strategy). After adjusting confounders, moderate/severe MR was not independently associated with higher risk for the primary outcome measure in the initial AVR strategy (hazard ratio [HR] 1.11, 95% confidence interval [CI] 0.67-1.83, P=0.69), and in the conservative strategy (HR 1.13, 95% CI 0.93-1.37, P=0.22). CONCLUSIONS: Concomitant moderate/severe MR was not independently associated with higher risk for the primary outcome measure regardless of the initial treatment strategy.

Daple deficiency causes hearing loss in adult mice by inducing defects in cochlear stereocilia and apical microtubules.

The V-shaped arrangement of hair bundles on cochlear hair cells is critical for auditory sensing. However, regulation of hair bundle arrangements has not been fully understood. Recently, defects in hair bundle arrangement were reported in postnatal Dishevelled-associating protein (ccdc88c, alias Daple)-deficient mice. In the present study, we found that adult Daple-/- mice exhibited hearing disturbances over a broad frequency range through auditory brainstem response testing. Consistently, distorted patterns of hair bundles were detected in almost all regions, more typically in the basal region of the cochlear duct. In adult Daple-/- mice, apical microtubules were irregularly aggregated, and the number of microtubules attached to plasma membranes was decreased. Similar phenotypes were manifested upon nocodazole treatment in a wild type cochlea culture without affecting the microtubule structure of the kinocilium. These results indicate critical role of Daple in hair bundle arrangement through the orchestration of apical microtubule distribution, and thereby in hearing, especially at high frequencies.

Coronary Revascularization in the Past Two Decades in Japan (From the CREDO-Kyoto PCI/CABG Registries Cohort-1, -2, and -3).

The treatment of coronary artery disease has substantially changed over the past two decades. However, it is unknown whether and how much these changes have contributed to the improvement of long-term outcomes after coronary revascularization. We assessed trends in the demographics, practice patterns and long-term outcomes in 24,951 patients who underwent their first percutaneous coronary intervention (PCI) (n = 20,106), or isolated coronary artery bypass grafting (CABG) (n = 4,845) using the data in a series of the CREDO-Kyoto PCI/CABG Registries (Cohort-1 [2000 to 2002]: n = 7,435, Cohort-2 [2005 to 2007]: n = 8,435, and Cohort-3 [2011 to 2013]: n = 9,081). From Cohort-1 to Cohort-3, the patients got progressively older across subsequent cohorts (67.0 ± 10.0, 68.4 ± 9.9, and 69.8 ± 10.2 years, ptrend < 0.001). There was increased use of PCI over CABG (73.5%, 81.9%, and 85.2%, ptrend < 0.001) and increased prevalence of evidence-based medications use over time. The cumulative 3-year incidence of all-cause death was similar across the 3 cohorts (9.0%, 9.0%, and 9.3%, p = 0.74), while cardiovascular death decreased over time (5.7%, 5.1%, and 4.8%, p = 0.03). The adjusted risk for all-cause death and for cardiovascular death progressively decreased from Cohort-1 to Cohort-2 (HR:0.89, 95%CI:0.80 to 0.99, p = 0.03, and HR:0.80, 95%CI:0.70 to 0.92, p = 0.002, respectively), and from Cohort-2 to Cohort-3 (HR:0.86, 95%CI:0.78 to 0.95, p = 0.004, and HR:0.77, 95%CI:0.67-0.89, p < 0.001, respectively). The risks for stroke and repeated coronary revascularization also improved over time. In conclusions, we found a progressive and substantial reduction of adjusted risk for all-cause death, cardiovascular death, stroke, and repeated coronary revascularization over the past two decades in Japan.

Planar cell polarity induces local microtubule bundling for coordinated ciliary beating.

Multiciliated cells (MCCs) in tracheas generate mucociliary clearance through coordinated ciliary beating. Apical microtubules (MTs) play a crucial role in this process by organizing the planar cell polarity (PCP)-dependent orientation of ciliary basal bodies (BBs), for which the underlying molecular basis remains elusive. Herein, we found that the deficiency of Daple, a dishevelled-associating protein, in tracheal MCCs impaired the planar polarized apical MTs without affecting the core PCP proteins, causing significant defects in the BB orientation at the cell level but not the tissue level. Using live-cell imaging and ultra-high voltage electron microscope tomography, we found that the apical MTs accumulated and were stabilized by side-by-side association with one side of the apical junctional complex, to which Daple was localized. In vitro binding and single-molecule imaging revealed that Daple directly bound to, bundled, and stabilized MTs through its dimerization. These features convey a PCP-related molecular basis for the polarization of apical MTs, which coordinate ciliary beating in tracheal MCCs.

Comparison of Outcomes of Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting Among Patients With Three-Vessel Coronary Artery Disease in the New-Generation Drug-Eluting Stents Era (From CREDO-Kyoto PCI/CABG Registry Cohort-3).

There is a scarcity of data comparing long-term clinical outcomes between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with three-vessel coronary artery disease (3VD) in the new-generation drug-eluting stents era. CREDO-Kyoto PCI/CABG registry Cohort-3 enrolled 14927 consecutive patients who had undergone first coronary revascularization with PCI or isolated CABG between January 2011 and December 2013. We identified 2525 patients with 3VD (PCI: n = 1747 [69%], and CABG: n = 778 [31%]). The primary outcome measure was all-cause death. Median follow-up duration was 5.7 (interquartile range: 4.4 to 6.6) years. The cumulative 5-year incidence of all-cause death was significantly higher in the PCI group than in the CABG group (19.8% vs 13.2%, log-rank p = 0.001). After adjusting confounders, the excess risk of PCI relative to CABG for all-cause death remained significant (HR, 1.45; 95% CI, 1.14 to 1.86; p = 0.003), which was mainly driven by the excess risk for non-cardiovascular death (HR, 1.88; 95% CI, 1.30 to 2.79; p = 0.001), while there was no excess risk for cardiovascular death between PCI and CABG (HR, 1.19; 95% CI, 0.87 to 1.64; p = 0.29). There was significant excess risk of PCI relative to CABG for myocardial infarction (HR, 1.77; 95% CI, 1.19 to 2.69; p = 0.006), whereas there was no excess risk of PCI relative to CABG for stroke (HR, 1.24; 95% CI, 0.83 to 1.88; p = 0.30). In conclusion, in the present study population reflecting real-world clinical practice in Japan, PCI compared with CABG was associated with significantly higher risk for all-cause death, while there was no excess risk for cardiovascular death between PCI and CABG.

Vasopressin escape and memory impairment in a model of chronic syndrome of inappropriate secretion of antidiuretic hormone in mice.

Recently, chronic hyponatremia, even mild, has shown to be associated with poor quality of life and high mortality. The mechanism by which hyponatremia contributes to those symptoms, however, remains to be elucidated. Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a primary cause of hyponatremia. Appropriate animal models are crucial for investigating the pathophysiology of SIADH. A rat model of SIADH has been generally used and mouse models have been rarely used. In this study, we developed a mouse model of chronic SIADH in which stable and sustained hyponatremia occurred after 3-week continuous infusion of the vasopressin V2 receptor agonist 1-desamino-8-D-arginine vasopressin (dDAVP) and liquid diet feeding to produce chronic water loading. Weight gain in chronic SIADH mice at week 2 and 3 after starting dDAVP injection was similar to that of control mice, suggesting that the animals adapted to chronic hyponatremia and grew up normally. AQP2 expression in the kidney, which reflects the renal action of vasopressin, was decreased in dDAVP-infused water-loaded mice as compared with control mice that received the same dDAVP infusion but were fed pelleted chow. These results suggest that "vasopressin escape" occurred, which is an important process for limiting potentially fatal severe hyponatremia. Behavioral analyses using the contextual and cued fear conditioning test and T-maze test demonstrated cognitive impairment, especially working memory impairment, in chronic SIADH mice, which was partially restored after correcting hyponatremia. Our results suggest that vasopressin escape occurred in chronic SIADH mice and that chronic hyponatremia contributed to their memory impairment.

A microtubule-LUZP1 association around tight junction promotes epithelial cell apical constriction.

Apical constriction is critical for epithelial morphogenesis, including neural tube formation. Vertebrate apical constriction is induced by di-phosphorylated myosin light chain (ppMLC)-driven contraction of actomyosin-based circumferential rings (CRs), also known as perijunctional actomyosin rings, around apical junctional complexes (AJCs), mainly consisting of tight junctions (TJs) and adherens junctions (AJs). Here, we revealed a ppMLC-triggered system at TJ-associated CRs for vertebrate apical constriction involving microtubules, LUZP1, and myosin phosphatase. We first identified LUZP1 via unbiased screening of microtubule-associated proteins in the AJC-enriched fraction. In cultured epithelial cells, LUZP1 was found localized at TJ-, but not at AJ-, associated CRs, and LUZP1 knockout resulted in apical constriction defects with a significant reduction in ppMLC levels within CRs. A series of assays revealed that ppMLC promotes the recruitment of LUZP1 to TJ-associated CRs, where LUZP1 spatiotemporally inhibits myosin phosphatase in a microtubule-facilitated manner. Our results uncovered a hitherto unknown microtubule-LUZP1 association at TJ-associated CRs that inhibits myosin phosphatase, contributing significantly to the understanding of vertebrate apical constriction.

Loss of Fbxw7 Impairs Development of and Induces Heterogeneous Tumor Formation in the Mouse Mammary Gland.

Fbxw7 is an F-box protein that contributes to regulation of cell proliferation and cell fate determination as well as to tumor suppression in various tissues. In this study, we generated mice with mammary gland-specific ablation of Fbxw7 (Blg-Cre/Fbxw7 F/F mice) and found that most neonates born to mutant dams die soon after birth as a result of defective maternal lactation. The mammary gland of mutant dams was markedly atrophic and manifested both excessive cell proliferation and apoptosis in association with the accumulation of Notch1 and p63. Despite the hypoplastic nature of the mutant mammary gland, Blg-Cre/Fbxw7 F/F mice spontaneously developed mammary tumors that resembled basal-like carcinoma with marked intratumoral heterogeneity. Additional inactivation of Trp53 in Blg-Cre/Fbxw7 F/F mice further promoted onset and development of mammary tumors, suggesting that spontaneous mutation of Trp53 may facilitate transition of hypoplastic mammary lesions to aggressive cancer in mice lacking Fbxw7. RNA-sequencing analysis of epithelial- and mesenchymal-like cell lines from a Blg-Cre/Fbxw7 F/F mouse tumor revealed an increased mutation rate and structural alterations in the tumor and differential expression of upstream transcription factors including known targets of Fbxw7. Together, our results implicate Fbxw7 in the regulation of cell differentiation and in tumor suppression in the mammary gland. Loss of Fbxw7 increases mutation rate and chromosome instability, activates signaling pathways governed by transcription factors regulated by Fbxw7, and triggers the development of mammary tumors with prominent heterogeneity. SIGNIFICANCE: Mammary gland-specific ablation of Fbxw7 in mice results in defective gland development and spontaneous mammary tumor formation reminiscent of human basal-like carcinoma with intratumoral heterogeneity. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/24/5515/F1.large.jpg.

Impact of concomitant tricuspid regurgitation on long-term outcomes in severe aortic stenosis.

AIMS: Tricuspid regurgitation (TR) has been reported to be associated with worse survival in various heart diseases, but there are few data in aortic stenosis (AS). METHODS AND RESULTS: In the Contemporary Outcomes after Surgery and Medical Treatment in Patients with Severe Aortic Stenosis (CURRENT AS) Registry enrolling 3815 consecutive patients with severe AS, there were 628 patients with moderate or severe TR (TR group) and 3187 patients with no or mild TR (no TR group). The study patients were subdivided into the initial aortic valve replacement (AVR) stratum (n = 1197) and the conservative stratum (n = 2618) according to treatment strategy. The primary outcome measure was a composite of aortic valve-related death or hospitalization due to heart failure. The 5-year freedom rate from the primary outcome measure was significantly lower in the TR group than in the no TR group (49.1% vs. 67.3%, P < 0.001). Even after adjusting for confounders, the excess risk of TR relative to no TR for the primary outcome measure remained significant [hazard ratio (HR): 1.25, 95% confidence interval (CI): 1.06-1.48; P = 0.008]. The trend for the excess adjusted risk in the TR group was consistent in the initial AVR and the conservative strata (HR 1.55, 95% CI: 0.97-2.48; P = 0.07; HR 1.22, 95% CI: 1.02-1.46; P = 0.03, respectively). In the initial AVR stratum, the 5-year freedom rate from the primary outcome measure was not different between the two groups with (n = 56) or without (n = 91) concomitant tricuspid annuloplasty (61.5% vs. 72.1%, P = 0.48). CONCLUSION: The presence of clinically significant TR concomitant with severe AS is associated with a poor long-term outcome, regardless of the initial treatment strategy.

Early Surgery vs. Surgery After Watchful Waiting for Asymptomatic Severe Aortic Stenosis.

BACKGROUND: There is no large-scale study comparing postoperative mortality after aortic valve replacement (AVR) for asymptomatic severe aortic stenosis (AS) between initial treatment with AVR vs. eventual AVR after conservative management. Methods and Results: We analyzed data from a multicenter registry enrolling 3,815 consecutive patients with severe AS. Of 1,808 asymptomatic patients, 286 patients initially underwent AVR (initial AVR group), and 377 patients were initially managed conservatively and eventually underwent AVR (AVR after watchful waiting group). Mortality after AVR was compared between the 2 groups. Subgroup analysis according to peak aortic jet velocity (Vmax) at diagnosis was also conducted. There was no significant difference between the 2 groups in 5-year overall survival (OS; 86.0% vs. 84.1%, P=0.34) or cardiovascular death-free survival (DFS; 91.3% vs. 91.1%, P=0.61), but on subgroup analysis of patients with Vmax ≥4.5 m/s at diagnosis, the initial AVR group was superior to the AVR after watchful waiting group in both 5-year OS (88.4% vs. 70.6%, P=0.003) and cardiovascular DFS (91.9% vs. 81.7%, P=0.023). CONCLUSIONS: Asymptomatic severe AS patients who underwent AVR after watchful waiting had a postoperative survival rate similar to those who initially underwent AVR. In a subgroup of patients with Vmax ≥4.5 m/s at diagnosis, however, the AVR after watchful waiting group had worse postoperative survival rate than the initial AVR group.