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The aim of this study was to investigate whether low-intensity pulsed ultrasound (LIPUS) promotes myocardial cell viability in three-dimensional (3D) cell-laden gelatin methacryloyl (GelMA) scaffolds. Cardiomyoblasts (H9C2s) were mixed in 6% (w/v) GelMA bio-inks and printed using an extrusion-based 3D bioprinter. These scaffolds were exposed to LIPUS with different parameters or sham-irradiated to optimize the LIPUS treatment. The viability of H9C2s was measured using Cell Counting Kit-8 (CCK8), cell cycle, and live and dead cell double-staining assays. Western blot analysis was performed to determine the protein expression levels. We successfully fabricated 3D bio-printed cell-laden GelMA scaffolds. CCK8 and live and dead cell double-staining assays indicated that the optimal conditions for LIPUS were a frequency of 0.5 MHz and an exposure time of 10 min. Cell cycle analysis showed that LIPUS promoted the entry of cells into the S and G2/M phases from the G0/G1 phase. Western blot analysis revealed that LIPUS promoted the phosphorylation and activation of ERK1/2 and PI3K-Akt. The ERK1/2 inhibitor (U0126) and PI3K inhibitor (LY294002) significantly reduced LIPUS-induced phosphorylation of ERK1/2 and PI3K-Akt, respectively, which in turn reduced the LIPUS-induced viability of H9C2s in 3D bio-printed cell-laden GelMA scaffolds. A frequency of 0.5 MHz and exposure time of 10 min for LIPUS exposure can be adapted to achieve optimized culture effects on myocardial cells in 3D bio-printed cell-laden GelMA scaffolds via the ERK1/2 and PI3K-Akt signaling pathways. [ABSTRACT FROM AUTHOR]

Objective: To explore the feasibility of using cRGD-GNR-PFP-NPs to assess plaque vulnerability in an atherosclerotic plaque mouse model by dual-modal photoacoustic/ultrasonic imaging., Methods: A nanomolecular probe containing gold nanorods (GNRs) and perfluoropentane (PFP) coated with the cyclic Arg-Gly-Asp (cRGD) peptide were prepared by double emulsion solvent evaporation and carbodiimide methods. The morphology, particle size, potential, cRGD conjugation and absorption features of the nanomolecular probe were characterized, along with its in vitro phase transformation and photoacoustic/ultrasonic dual-modal imaging properties. In vivo fluorescence imaging was used to determine the distribution of cRGD-GNR-PFP-NPs in vivo in apolipoprotein E-deficient (ApoE -/- ) atherosclerotic plaque model mice, the optimal imaging time was determined, and photoacoustic/ultrasonic dual-modal molecular imaging of integrin αvβ3 expressed in atherosclerotic plaques was performed. Pathological assessments verified the imaging results in terms of integrin αvβ3 expression and plaque vulnerability., Results: cRGD-GNR-PFP-NPs were spherical with an appropriate particle size (average of approximately 258.03±6.75 nm), a uniform dispersion, and a potential of approximately -9.36±0.53 mV. The probe had a characteristic absorption peak at 780~790 nm, and the surface conjugation of the cRGD peptide reached 92.79%. cRGD-GNR-PFP-NPs were very stable in the non-excited state but very easily underwent phase transformation under low-intensity focused ultrasound (LIFU) and had excellent photoacoustic/ultrasonic dual-modal imaging capability. Mice fed a high-fat diet for 20 weeks had obvious hyperlipidemia with larger, more vulnerable plaques. These plaques could be specifically targeted by cRGD-GNR-PFP-NPs as determined by in vivo fluorescence imaging, and the enrichment of nanomolecular probe increased with the increasing of plaque vulnerability; the photoacoustic/ultrasound signals of the plaques in the high-fat group were stronger. The pathological assessments were in good agreement with the cRGD-GNR-PFP-NPs plaque accumulation, integrin αvβ3 expression and plaque vulnerability results., Conclusion: A phase variant photoacoustic/ultrasonic dual-modal cRGD nanomolecular probe was successfully prepared and can be used to identify plaque vulnerability safely and effectively., Competing Interests: The authors declare that there are no conflicts of interest in this work., (© 2024 Yu et al.)

Cell-cell junctions are dynamic structures that maintain cell cohesion and shape in epithelial tissues. During development, junctions undergo extensive rearrangements to drive the epithelial remodelling required for morphogenesis. This is particularly evident during axis elongation, where neighbour exchanges, cell-cell rearrangements and oriented cell divisions lead to large-scale alterations in tissue shape. Polarised vesicle trafficking of junctional components by the exocyst complex has been proposed to promote junctional rearrangements during epithelial remodelling, but the receptors that allow exocyst docking to the target membranes remain poorly understood. Here, we show that the adherens junction component Ras Association domain family 8 (RASSF8) is required for the epithelial re-ordering that occurs during Drosophila pupal wing proximo-distal elongation. We identify the exocyst component Sec15 as a RASSF8 interactor. Loss of RASSF8 elicits cytoplasmic accumulation of Sec15 and Rab11-containing vesicles. These vesicles also contain the nectin-like homophilic adhesion molecule Echinoid, the depletion of which phenocopies the wing elongation and epithelial packing defects observed in RASSF8 mutants. Thus, our results suggest that RASSF8 promotes exocyst-dependent docking of Echinoid-containing vesicles during morphogenesis., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Objective: To explore the monitoring value of left ventricular functional parameters obtained by bedside ultrasound combined with clinically relevant indicators in patients with veno-arterial extracorporeal membrane oxygenation (VA-ECMO)., Methods: A retrospective study was conducted. A total of 24 patients receiving VA-ECMO adjuvant support in Renmin Hospital of Wuhan University from June 2018 to January 2020 were selected. The bedside ultrasound was performed on the first day of ECMO support, the day before weaning, the clinical indicators before weaning were obtained. The differences in clinical indicators and the left ventricular functional parameters between the two groups of whether weaning successfully were compared; univariate Logistic regression analysis was used to screen out the related factors affecting weaning., Results: Sixteen patients were successful weaned and 8 patients failed. Compared with the weaning failure group, patients in the weaning success group required less continuous renal replacement therapy (CRRT, cases: 4 vs. 6, P < 0.05), mean arterial pressure (MAP) before weaning was higher [mmHg (1 mmHg = 0.133 kPa): 84.64±9.55 vs. 62.30±8.79, P < 0.05], and the pulse oxygen saturation (SpO 2 ) was also higher (0.966±0.670 vs. 0.866±0.061, P < 0.05), while vasoactive-inotropic score (VIS), serum creatinine (SCr) and serum lactic acid (Lac) were lower [VIS score: 7.27±1.42 vs. 16.93±8.52, SCr (μmol/L): 123.60±83.64 vs. 213.10±117.39, Lac (mmol/L): 1.94±0.91 vs. 5.62±5.48, all P < 0.05]. Univariate Logistic regression analysis showed that the MAP, VIS, SCr, Lac, SpO 2 before weaning were the related factors affecting weaning [odds ratio (OR) were 0.306, -0.740, -0.011, -0.632, -4.069; 95% confidence interval (95%CI) were 1.065-1.732, 0.235-0.899, 0.979-0.999, 0.285-0.992 and 0.001-0.208; P values were 0.014, 0.022, 0.038, 0.047, 0.002]. In the weaning success group, left ventricular ejection fraction (LVEF), velocity of mitralannulus in systolic (LatSa), maximum flow velocity of aortic valve (AV-Vmax), velocity-time integral (VTI), left ventricular global longitudinal strain (LVGLS), left ventricular global longitudinal strain rate (LVGLSr) were all increased on the day before ECMO weaning compared with the first day of ECMO support [LVEF: 0.40±0.05 vs. 0.28±0.07, LatSa (cm/s): 6.81±0.91 vs. 4.62±1.02, AV-Vmax (cm/s): 104.81±33.98 vs. 64.44±16.85, VTI (cm): 14.56±3.11 vs. 7.96±1.98, LVGLS: (-8.95±2.59)% vs. (-5.26±1.28)%, LVGLSr (1/s): -0.48±0.11 vs. -0.29±0.09], whereas the ECMO flow was significantly reduced (L/min: 1.46±0.47 vs. 2.64±0.31), the differences were statistically significant (all P < 0.05). There was no significant difference in left ventricular functional parameters between the first day of ECMO support and the day before ECMO weaning in the weaning failure group. Compared with the weaning failure group, the weaning success group had higher LVEF, LatSa, AV-Vmax, VTI, LVGLS, LVGLSr on the day before ECMO weaning [LVEF: 0.40±0.05 vs. 0.26±0.07, LatSa (cm/s): 6.81±0.91 vs. 4.31±1.03, AV-Vmax (cm/s): 104.81±33.98 vs. 67.67±18.46, VTI (cm): 14.56±3.11 vs. 7.75±2.77, LVGLS: (-8.95±2.59)% vs. (-4.81±1.81)%, LVGLSr (1/s): -0.48±0.11 vs. -0.30±0.10, all P < 0.05] and lower ECMO flow (L/min: 1.46±0.47 vs. 2.20±0.62, P < 0.05)., Conclusions: Bedside echocardiographic left ventricular function parameters (LVEF, LatSa, AV-Vmax, VTI, LVGLS, LVGLSr) combined with clinical indicators (MAP, VIS, SCr, Lac, SpO 2 ) were helpful to evaluate the therapeutic effect of patients receiving VA-ECMO support and can provide important guiding value in the selection of VA-ECMO weaning timing and the judgment of prognosis.

Morphogenesis is crucial during development to generate organs and tissues of the correct size and shape. During Drosophila late eye development, interommatidial cells (IOCs) rearrange to generate the highly organized pupal lattice, in which hexagonal ommatidial units pack tightly. This process involves the fine regulation of adherens junctions (AJs) and of adhesive E-Cadherin (E-Cad) complexes. Localized accumulation of Bazooka (Baz), the Drosophila PAR3 homolog, has emerged as a critical step to specify where new E-Cad complexes should be deposited during junction remodeling. However, the mechanisms controlling the correct localization of Baz are still only partly understood. We show here that Drosophila Magi, the sole fly homolog of the mammalian MAGI scaffolds, is an upstream regulator of E-Cad-based AJs during cell rearrangements, and that Magi mutant IOCs fail to reach their correct position. We uncover a direct physical interaction between Magi and the Ras association domain protein RASSF8 through a WW domain-PPxY motif binding, and show that apical Magi recruits the RASSF8-ASPP complex during AJ remodeling in IOCs. We further show that this Magi complex is required for the cortical recruitment of Baz and of the E-Cad-associated proteins α- and β-catenin. We propose that, by controlling the proper localization of Baz to remodeling junctions, Magi and the RASSF8-ASPP complex promote the recruitment or stabilization of E-Cad complexes at junction sites., (© 2015. Published by The Company of Biologists Ltd.)

Post-translational modification by ubiquitin and ubiquitin-like (UBL) proteins is a key mechanism for cellular control. The specificity of the enzymes of ubiquitination and their close paralogs is dependent on their molecular electrostatic potentials. For example, analysis of molecular electrostatic potentials and electrostatically key residues can account for the selectivity of different E1s (activating enzymes) and of different SUMO proteases. The molecular interactions of the ubiquitin conjugating enzymes, the ubiquitin family proteins (UFP) and UBL domains are discussed in detail. An interesting observation is that the Non Canonical Ubiquitin Conjugating Enzymes (NCUBEs) have electrostatic potentials that are more similar to the UBC9 orthologs, the SUMO conjugating enzymes, than they are to other ubiquitin conjugating enzymes. It had previously been suggested that UBC9 may select for SUMO based on its difference in electrostatic potential as compared to other E2s but the NCUBE exception suggests that this may not be the case. The web site http://www.ubiquitin-resource.org/ allows users to find the E2s most electrostatically similar to a query E2. Where possible, models have been made for all E2 domains in the SMART database (http://smart.embl-heidelberg.de/). A brief overview of molecular electrostatic potentials and their application to understanding protein function is also given.