3D Cinemagraphy from a Single Image

We present 3D Cinemagraphy, a new technique that marries 2D image animation with 3D photography. Given a single still image as input, our goal is to generate a video that contains both visual content animation and camera motion. We empirically find that naively combining existing 2D image animation and 3D photography methods leads to obvious artifacts or inconsistent animation. Our key insight is that representing and animating the scene in 3D space offers a natural solution to this task. To this end, we first convert the input image into feature-based layered depth images using predicted depth values, followed by unprojecting them to a feature point cloud. To animate the scene, we perform motion estimation and lift the 2D motion into the 3D scene flow. Finally, to resolve the problem of hole emergence as points move forward, we propose to bidirectionally displace the point cloud as per the scene flow and synthesize novel views by separately projecting them into target image planes and blending the results. Extensive experiments demonstrate the effectiveness of our method. A user study is also conducted to validate the compelling rendering results of our method.Comment: Accepted by CVPR 2023. Project page: https://xingyi-li.github.io/3d-cinemagraphy

Make-It-4D: Synthesizing a Consistent Long-Term Dynamic Scene Video from a Single Image

We study the problem of synthesizing a long-term dynamic video from only a single image. This is challenging since it requires consistent visual content movements given large camera motions. Existing methods either hallucinate inconsistent perpetual views or struggle with long camera trajectories. To address these issues, it is essential to estimate the underlying 4D (including 3D geometry and scene motion) and fill in the occluded regions. To this end, we present Make-It-4D, a novel method that can generate a consistent long-term dynamic video from a single image. On the one hand, we utilize layered depth images (LDIs) to represent a scene, and they are then unprojected to form a feature point cloud. To animate the visual content, the feature point cloud is displaced based on the scene flow derived from motion estimation and the corresponding camera pose. Such 4D representation enables our method to maintain the global consistency of the generated dynamic video. On the other hand, we fill in the occluded regions by using a pretrained diffusion model to inpaint and outpaint the input image. This enables our method to work under large camera motions. Benefiting from our design, our method can be training-free which saves a significant amount of training time. Experimental results demonstrate the effectiveness of our approach, which showcases compelling rendering results.Comment: accepted by ACM MM'2

Cell-Cycle-Regulated Interaction between Mcm10 and Double Hexameric Mcm2-7 Is Required for Helicase Splitting and Activation during S Phase

Mcm2-7 helicase is loaded onto double-stranded origin DNA as an inactive double hexamer (DH) in G1 phase. The mechanisms of Mcm2-7 remodeling that trigger helicase activation in S phase remain unknown. Here, we develop an approach to detect and purify the endogenous DHs directly. Through cellular fractionation, we provide in vivo evidence that DHs are assembled on chromatin in G1 phase and separated during S phase. Interestingly, Mcm10, a robust MCM interactor, co-purifies exclusively with the DHs in the context of chromatin. Deletion of the main interaction domain, Mcm10 C terminus, causes growth and S phase defects, which can be suppressed through Mcm10-MCM fusions. By monitoring the dynamics of MCM DHs, we show a significant delay in DH dissolution during S phase in the Mcm10-MCM interaction-deficient mutants. Therefore, we propose an essential role for Mcm10 in Mcm2-7 remodeling through formation of a cell-cycle-regulated supercomplex with DHs

Flexibly-oriented double Cdc45-MCM-GINS intermediates during eukaryotic replicative helicase maturation

The core of the eukaryotic helicase MCM is loaded as an inactive double hexamer (DH). How it is assembled into two active Cdc45-MCM-GINS (CMG) helicases remains elusive. Here, we report that at the onset of S phase, both Cdc45 and GINS are loaded as dimers onto MCM DH, resulting in formation of double CMG (d-CMG). As S phase proceeds, d-CMGs gradually mature into two single CMG-centered replisome progression complexes (RPCs). Mass spectra reveal that RPA and DNA Pol α/primase co-purify exclusively with RPCs, but not with d-CMGs. Consistently, d-CMGs are not able to catalyze either the unwinding or de novo DNA synthesis, while RPCs can do both. Using single-particle electron microscopy, we have obtained 2D class averages of d-CMGs. Compared to MCM DHs, they display heterogeneous, flexibly orientated and partially loosened conformations with changed interfaces. The dumbbell-shaped d-CMGs are mediated by Ctf4, while other types of d-CMGs are independent of Ctf4. These data suggest CMG dimers as bona fide intermediates during MCM maturation, providing an additional quality control for symmetric origin activation and bidirectional replication

Flexibly-oriented double Cdc45-MCM-GINS intermediates during eukaryotic replicative helicase maturation

The core of the eukaryotic helicase MCM is loaded as an inactive double hexamer (DH). How it is assembled into two active Cdc45-MCM-GINS (CMG) helicases remains elusive. Here, we report that at the onset of S phase, both Cdc45 and GINS are loaded as dimers onto MCM DH, resulting in formation of double CMG (d-CMG). As S phase proceeds, d-CMGs gradually mature into two single CMG-centered replisome progression complexes (RPCs). Mass spectra reveal that RPA and DNA Pol α/primase co-purify exclusively with RPCs, but not with d-CMGs. Consistently, d-CMGs are not able to catalyze either the unwinding or de novo DNA synthesis, while RPCs can do both. Using single-particle electron microscopy, we have obtained 2D class averages of d-CMGs. Compared to MCM DHs, they display heterogeneous, flexibly orientated and partially loosened conformations with changed interfaces. The dumbbell-shaped d-CMGs are mediated by Ctf4, while other types of d-CMGs are independent of Ctf4. These data suggest CMG dimers as bona fide intermediates during MCM maturation, providing an additional quality control for symmetric origin activation and bidirectional replication

The DNA Pol ϵ stimulatory activity of Mrc1 is modulated by phosphorylation

DNA replication checkpoint (Mec1-Mrc1-Rad53 in budding yeast) is an evolutionarily conserved surveillance system to ensure proper DNA replication and genome stability in all eukaryotes. Compared to its well-known function as a mediator of replication checkpoint, the exact role of Mrc1 as a component of normal replication forks remains relatively unclear. In this study, we provide in vitro biochemical evidence to support that yeast Mrc1 is able to enhance the activity of DNA polymerase ϵ (Pol ϵ), the major leading strand replicase. Mrc1 can selectively bind avidly to primer/template DNA bearing a single-stranded region, but not to double-stranded DNA (dsDNA). Mutations of the lysine residues within basic patch 1 (BP1) compromise both DNA binding and polymerase stimulatory activities. Interestingly, Mrc1-3D, a mutant mimicking phosphorylation by the Hog1/MAPK kinase during the osmotic stress response, retains DNA binding but not polymerase stimulation. The stimulatory effect is also abrogated in Mrc1 purified from cells treated with hydroxyurea (HU), which elicits replication checkpoint activation. Taken together with previous findings, these results imply that under unperturbed condition, Mrc1 has a DNA synthesis stimulatory activity, which can be eliminated via Mrc1 phosphorylation in response to replication and/or osmotic stresses

The DNA Pol ϵ stimulatory activity of Mrc1 is modulated by phosphorylation

DNA replication checkpoint (Mec1-Mrc1-Rad53 in budding yeast) is an evolutionarily conserved surveillance system to ensure proper DNA replication and genome stability in all eukaryotes. Compared to its well-known function as a mediator of replication checkpoint, the exact role of Mrc1 as a component of normal replication forks remains relatively unclear. In this study, we provide in vitro biochemical evidence to support that yeast Mrc1 is able to enhance the activity of DNA polymerase ϵ (Pol ϵ), the major leading strand replicase. Mrc1 can selectively bind avidly to primer/template DNA bearing a single-stranded region, but not to double-stranded DNA (dsDNA). Mutations of the lysine residues within basic patch 1 (BP1) compromise both DNA binding and polymerase stimulatory activities. Interestingly, Mrc1-3D, a mutant mimicking phosphorylation by the Hog1/MAPK kinase during the osmotic stress response, retains DNA binding but not polymerase stimulation. The stimulatory effect is also abrogated in Mrc1 purified from cells treated with hydroxyurea (HU), which elicits replication checkpoint activation. Taken together with previous findings, these results imply that under unperturbed condition, Mrc1 has a DNA synthesis stimulatory activity, which can be eliminated via Mrc1 phosphorylation in response to replication and/or osmotic stresses

Ketamine Promotes LPS-Induced Pulmonary Autophagy and Reduces Apoptosis through the AMPK/mTOR Pathway

To explore the protective effect of ketamine on acute lung injury (ALI) in sepsis mice regarding the autophagy and apoptosis, lipopolysaccharide (LPS) was used to construct a sepsis-induced ALI model. In in vivo experiments, ketamine at a concentration of 20 mg/kg was injected before modeling. The serum levels of inflammatory factors IL-1β, IL-6, and TNF-α were detected by enzyme-linked immunosorbent assay (ELISA) kit. At the same time, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect apoptosis-related factors Bax and Bcl-2 and autophagy-related factors Beclin-1 and P62. In in vitro experiment, firstly, Cell Counting Kit-8 (CCK8) assay was used to detect the cell viability and identify optimal concentration of ketamine. TUNEL staining, Western blotting (WB), and qRT-PCR were used to detect alveolar type II epithelial cells (AEC II) AEC II cell apoptosis. The content of inflammatory factors in the cell supernatant was detected by kits and the autophagy intensity of AEC II cells was detected by PCR and WB. At the same time, the expression changes of AMPK/mTOR pathway were detected by WB technology. Compared with the Sham group, the dry-wet ratio of the lung tissue in the LPS group was obviously increased, the expression of inflammatory factors in the serum was upregulated, and apoptosis and autophagy activation occurred. In the LPS + ketamine group, ketamine significantly promoted autophagy intensity and inhibited inflammatory response, thereby reducing apoptosis. In vitro, 1 mmol/L ketamine can effectively improve the viability of AEC II cells after LPS treatment, promote autophagy, and decrease cell apoptosis. And we found that the above-mentioned effect of ketamine was by regulating the activation of AMPK/mTOR pathway. In this study, we demonstrated that LPS treatment can induce inflammation and autophagy and induce apoptosis in lung cells. In contrast, AMPK expression was activated after ketamine treatment, inhibiting the mTOR pathway and promoting autophagy, thereby alleviating the apoptosis of AEC II cells

Establishment and verification of the first prognostic nomograms in locally advanced thyroid cancer based on the analysis of clinical and follow-up information on 2396 patients

Background and objectives: The purpose of this research was to develop and validate the first prognostic nomograms for 3-, 5-, and 10-year cancer-specific survival (CSS) and overall survival (OS) in patients diagnosed with locally advanced thyroid cancer (LATC) by evaluating independent predictors of prognosis in a population of LATC patients. Methods: Demographics, clinicopathologic characteristics, treatment, and follow-up of 2396 LATC patients in the surveillance, epidemiology, and end results database from 2004 to 2015 were retrospectively analyzed and compared with patients with LATC according to staging. We randomized all LATC patients into training and validation groups in a 7:3 ratio. Cox regression analyses helped us to derive independent prognostic factors for LATC patients. According to these results, we established and validated the first prognostic nomograms and risk stratification. Results: In our research, the clinical information of LATC patients was compared and significant differences were found in the relevant variables including CSS and OS (P < 0.05), with CSS of 82.0 % and 49.0 %, and OS of 70.6 % and 40.0 %, respectively. Cox regression analyses showed that age at diagnosis, tumor diameter, presence of DM, extrathyroidal extension sites, histological type, thyroidectomy scope, radiotherapy status, and chronological sequence of radiotherapy and surgery were observably correlated with CSS in LATC patients, and in addition to the above factors, gender, marital status, and chemotherapy status were also observably correlated with OS in LATC patients. The prognostic predictive power of the above factors is visualized by the Kaplan-Meier survival curve. The concordance index of nomograms for CSS and OS were 0.933, 0.925, and 0.926 (CSS), 0.918, 0.909, and 0.906 (OS), respectively, and the time-dependent receiver operating characteristic curve, area under curve, calibration curve and decision curve analysis curve indicate that the nomograms have good discriminatory ability, accuracy and clinical applicability in both the training and validation groups. Conclusions: In these findings, we drawed a conclusion that there were significant differences in clinical information between patients with T4a and T4b LATC, and we established and validated the first prognostic nomograms and risk stratification of CSS and OS for LATC patients at 3, 5, and 10 years, which will help clinicians to individualize their postoperative treatment and individualized follow-up

Cul4-Ddb1 ubiquitin ligases facilitate DNA replication-coupled sister chromatid cohesion through regulation of cohesin acetyltransferase Esco2.

Cohesin acetyltransferases ESCO1 and ESCO2 play a vital role in establishing sister chromatid cohesion. How ESCO1 and ESCO2 are controlled in a DNA replication-coupled manner remains unclear in higher eukaryotes. Here we show a critical role of CUL4-RING ligases (CRL4s) in cohesion establishment via regulating ESCO2 in human cells. Depletion of CUL4A, CUL4B or DDB1 subunits substantially reduces the normal cohesion efficiency. We also show that MMS22L, a vertebrate ortholog of yeast Mms22, is one of DDB1 and CUL4-associated factors (DCAFs) involved in cohesion. Several lines of evidence show selective interaction of CRL4s with ESCO2 through LxG motif, which is lost in ESCO1. Depletion of either CRL4s or ESCO2 causes a defect in SMC3 acetylation, which can be rescued by HDAC8 inhibition. More importantly, both CRL4s and PCNA act as mediators for efficiently stabilizing ESCO2 on chromatin and catalyzing SMC3 acetylation. Taken together, we propose an evolutionarily conserved mechanism in which CRL4s and PCNA promote ESCO2-dependent establishment of sister chromatid cohesion