An ATP13A1-assisted topogenesis pathway for folding multi-spanning membrane proteins.

Many multi-spanning membrane proteins contain poorly hydrophobic transmembrane domains (pTMDs) protected from phospholipid in mature structure. Nascent pTMDs are difficult for translocon to recognize and insert. How pTMDs are discerned and packed into mature, muti-spanning configuration remains unclear. Here, we report that pTMD elicits a post-translational topogenesis pathway for its recognition and integration. Using six-spanning protein adenosine triphosphate-binding cassette transporter G2 (ABCG2) and cultured human cells as models, we show that ABCG2's pTMD2 can pass through translocon into the endoplasmic reticulum (ER) lumen, yielding an intermediate with inserted yet mis-oriented downstream TMDs. After translation, the intermediate recruits P5A-ATPase ATP13A1, which facilitates TMD re-orientation, allowing further folding and the integration of the remaining lumen-exposed pTMD2. Depleting ATP13A1 or disrupting pTMD-characteristic residues arrests intermediates with mis-oriented and exposed TMDs. Our results explain how a "difficult" pTMD is co-translationally skipped for insertion and post-translationally buried into the final correct structure at the late folding stage to avoid excessive lipid exposure.

TMUB1 is an endoplasmic reticulum-resident escortase that promotes the p97-mediated extraction of membrane proteins for degradation.

Membrane protein clients of endoplasmic reticulum (ER)-associated degradation must be retrotranslocated from the ER membrane by the AAA-ATPase p97 for proteasomal degradation. Before direct engagement with p97, client transmembrane domains (TMDs) that have partially or fully crossed the membrane must be constantly shielded to avoid non-native interactions. How client TMDs are seamlessly escorted from the membrane to p97 is unknown. Here, we identified ER-anchored TMUB1 as a TMD-specific escortase. TMUB1 interacts with the TMD of clients within the membrane and holds ∼10-14 residues of a hydrophobic sequence that is exposed out of membrane, using its transmembrane and cytosolic regions, respectively. The ubiquitin-like domain of TMUB1 recruits p97, which can pull client TMDs from bound TMUB1 into the cytosol. The disruption of TMUB1 escortase activity impairs retrotranslocation and stabilizes retrotranslocating intermediates of client proteins within the ER membrane. Thus, TMUB1 promotes TMD segregation by safeguarding the TMD movement from the membrane to p97.

RNF126-Mediated Reubiquitination Is Required for Proteasomal Degradation of p97-Extracted Membrane Proteins.

Valosin-containing protein (VCP)/p97 is an AAA-ATPase that extracts polyubiquitinated substrates from multimeric macromolecular complexes and biological membranes for proteasomal degradation. During p97-mediated extraction, the substrate is largely deubiquitinated as it is threaded through the p97 central pore. How p97-extracted substrates are targeted to the proteasome with few or no ubiquitins is unknown. Here, we report that p97-extracted membrane proteins undergo a second round of ubiquitination catalyzed by the cytosolic ubiquitin ligase RNF126. RNF126 interacts with transmembrane-domain-specific chaperone BAG6, which captures p97-liberated substrates. RNF126 depletion in cells diminishes the ubiquitination of extracted membrane proteins, slows down their turnover, and dramatically stabilizes otherwise transient intermediates in the cytosol. We reconstitute the reubiquitination of a p97-extracted, misfolded multispanning membrane protein with purified factors. Our results demonstrate that p97-extracted substrates need to rapidly engage ubiquitin ligase-chaperone pairs that rebuild the ubiquitin signal for proteasome targeting to prevent harmful accumulation of unfolded intermediates.

Circadian clock-related genome-wide mendelian randomization identifies putatively genes for ulcerative colitis and its comorbidity.

BACKGROUND: Circadian rhythm is crucial to the function of the immune system. Disorders of the circadian rhythm can contribute to inflammatory diseases such as Ulcerative colitis (UC). This Mendelian Randomization (MR) analysis applies genetic tools to represent the aggregated statistical results of exposure to circadian rhythm disorders and UC and its comorbidities, allowing for causal inferences. METHODS: Summary statistics of protein, DNA methylation and gene expression quantitative trait loci in individuals of European ancestry (pQTL, mQTL, and eQTL, respectively) were used. Genetic variants located within or near 152 circadian clock-related genes and closely related to circadian rhythm disorders were selected as instrumental variables. Causal relationships with UC and its comorbidities were then estimated through employed Summary data-based Mendelian Randomization (SMR) and Inverse-Variance-Weighted MR (IVW-MR). RESULTS: Through preliminary SMR analysis, we identified a potential causal relationship between circadian clock-related genes and UC along with its comorbidities, which was further confirmed by IVW-MR analysis. Our study identified strong evidence of positive correlation involving seven overlapping genes (CSNK1E, OPRL1, PIWIL2, RORC, MAX, PPP5C, and AANAT) through MWAS and TWAS in UC, four overlapping genes (OPRL1, CHRNB2, FBXL17, and SIRT1) in UC with PSC, and three overlapping genes (ARNTL, USP7, and KRAS) in UC with arthropathy. CONCLUSIONS: This SMR study demonstrates the causal effect of circadian rhythm disorders in UC and its comorbidities. Furthermore, our investigation pinpointed candidate genes that could potentially serve as drug targets.

Improvement of coronary stent visualization using ultra-high-resolution photon-counting detector CT.

OBJECTIVES: This study aimed to compare the image quality and diagnostic performance of standard-resolution (SR) and ultra-high-resolution (UHR) coronary CT angiography (CCTA) based on photon-counting detector CT (PCD-CT) of coronary stents and explore the best reconstruction kernel for stent imaging. METHODS: From July 2023 to September 2023, patients were enrolled to undergo CCTA using a dual-source PCD-CT system after coronary angioplasty with stent placement. SR images with a slice thickness/increment of 0.6/0.4 mm were reconstructed using a vascular kernel (Bv48), while UHR images with a slice thickness/increment of 0.2/0.2 mm were reconstructed using vascular kernels of six sharpness levels (Bv48, Bv56, Bv60, Bv64, Bv72, and Bv76). The in-stent lumen diameters were evaluated. Subjective image quality was also evaluated by a 5-point Likert scale. Invasive coronary angiography was conducted in 12 patients (25 stents). RESULTS: Sixty-nine patients (68.0 [61.0, 73.0] years, 46 males) with 131 stents were included. All UHR images had significantly larger in-stent lumen diameter than SR images (p < 0.001). Specifically, UHR-Bv72 and UHR-Bv76 for in-stent lumen diameter (2.17 [1.93, 2.63] mm versus 2.20 [1.93, 2.59] mm) ranked the two best kernels. The subjective analysis demonstrated that UHR-Bv72 images had the most pronounced effect on reducing blooming artifacts, showcasing in-stent lumen and stent demonstration, and diagnostic confidence (p < 0.001). Furthermore, SR and UHR-Bv72 images showed a diagnostic accuracy of 78.3% (95% confidence interval [CI]: 56.3%-92.5%) and 88.0% (95%CI: 68.8%-97.5%), respectively. CONCLUSION: UHR CCTA by PCD-CT leads to significantly improved visualization and diagnostic performance of coronary stents, and Bv72 is the optimal reconstruction kernel showing the stent struts and in-stent lumen. CLINICAL RELEVANCE STATEMENT: The significantly improved visualization of coronary stents using ultra-high resolution CCTA could increase the diagnostic accuracy for in-stent restenosis and avoid unnecessary invasive quantitative coronary angiography, thus changing the clinical management for patients after percutaneous coronary intervention. KEY POINTS: Coronary stent imaging is challenging with energy-integrating detector CT due to "blooming artifacts." UHR images using a PCD-CT enhanced coronary stent visualization. UHR coronary stent imaging demonstrated improved diagnostic accuracy in clinical settings.

Prediction of heterosis in the recent rapeseed (Brassica napus) polyploid by pairing parental nucleotide sequences.

The utilization of heterosis is a successful strategy in increasing yield for many crops. However, it consumes tremendous manpower to test the combining ability of the parents in fields. Here, we applied the genomic-selection (GS) strategy and developed models that significantly increase the predictability of heterosis by introducing the concept of a regional parental genetic-similarity index (PGSI) and reducing dimension in the calculation matrix in a machine-learning approach. Overall, PGSI negatively affected grain yield and several other traits but positively influenced the thousand-seed weight of the hybrids. It was found that the C subgenome of rapeseed had a greater impact on heterosis than the A subgenome. We drew maps with overviews of quantitative-trait loci that were responsible for the heterosis (h-QTLs) of various agronomic traits. Identifications and annotations of genes underlying high impacting h-QTLs were provided. Using models that we elaborated, combining abilities between an Ogu-CMS-pool member and a potential restorer can be simulated in silico, sidestepping laborious work, such as testing crosses in fields. The achievements here provide a case of heterosis prediction in polyploid genomes with relatively large genome sizes.

Hypertension as an independent risk factor for severity and mortality in patients with COVID-19: a retrospective study.

PURPOSE OF THE STUDY: Hypertension is one of the most common comorbidities in COVID-19 pneumonia. However, whether it is an independent factor on the severity and mortality of COVID-19 has not been studied. STUDY DESIGN: In this study, 736 patients with a PCR-confirmed diagnosis of COVID-19 were included from 12 January 2020 to 25 March 2020. All patients were divided into two groups according to whether or not they were hypertensive. After propensity score matching (PSM) to remove the interference of mismatches in the baseline data, the clinical characteristics and outcomes of angiotensin II receptor blocker (ARB)/ACE inhibitors application were analysed. RESULTS: A total of 220 (29.9%) patients were hypertensive, and 516 (70.1%) patients were not hypertensive. PSM eliminated demographic and comorbidity differences between the two groups. Of all participants, 32 patients died (4.3% mortality), including 17 out of 220 in the hypertension group (7.7%) and 15 out of 516 in the non-hypertension group (2.9%). The incidence of intensive care unit (ICU) stay in the hypertension group (12.8%) was higher than in the non-hypertension group (5.3%) (p<0.05). Logistic regression analysis showed that hypertension was an independent risk factor for death, not other comorbidities. Kaplan-Meier analysis showed that mortality was higher in the hypertension group than in the non-hypertension group before and after PSM (p<0.05). There was no statistically significant difference in ICU therapy, mortality and hospitalisation time between hypertensive patients with or without ARBs/ACE inhibitors (p>0.05). CONCLUSION: Hypertension was an independent risk factor for the severity and mortality of patients with COVID-19. ARBs/ACE inhibitors should not be discontinued in hypertensive patients with COVID-19.

Deep-Learning-Assisted Single-Molecule Tracking on a Live Cell Membrane.

Single-molecule fluorescence imaging is a powerful tool to study protein function by tracking molecular position and distribution, but the precise and rapid identification of dynamic molecules remains challenging due to the heterogeneous distribution and interaction of proteins on the live cell membrane. We now develop a deep-learning (DL)-assisted single-molecule imaging method that can precisely distinguish the monomer and complex for rapid and real-time tracking of protein interaction. This DL-based model, which comprises convolutional layers, max pooling layers, and fully connected layers, is trained to reach an accuracy of >98% for identifying monomer and complex. We use this method to investigate the dynamic process of chemokine receptor CXCR4 on the live cell membrane during the early signaling stage. The results show that, upon ligand activation, the CXCR4 undergoes a dynamic process of forming a receptor complex. We further demonstrate that the CXCR4 complex tends to be internalized at 2.5-fold higher rate into the cell interior than the monomer via the clathrin-dependent pathway. This study is the first example to scrutinize the early signaling process of CXCR4 at the single-molecule level on the live cell membrane. We envision that this DL-assisted imaging method would be a broadly useful technique to study more protein families for elucidating their physiological and pathological functions.

A technique for delineating the unfolding requirements for substrate entry into retrotranslocons during endoplasmic reticulum-associated degradation.

The endoplasmic reticulum-associated degradation (ERAD) pathway mediates the endoplasmic reticulum-to-cytosol retrotranslocation of defective proteins through protein complexes called retrotranslocons. Defective proteins usually have complex conformations and topologies, and it is unclear how ERAD can thread these conformationally diverse protein substrates through the retrotranslocons. Here, we investigated the substrate conformation flexibility necessary for transport via retrotranslocons on the ERAD-L, ERAD-M, and HIV-encoded protein Vpu-hijacked ERAD branches. To this end, we appended various ERAD substrates with specific domains whose conformations were tunable in flexibility or tightness by binding to appropriate ligands. With this technique, we could define the capacity of specific retrotranslocons in disentangling very tight, less tight but well-folded, and unstructured conformations. The Hrd1 complex, the retrotranslocon on the ERAD-L branch, permitted the passage of substrates with a proteinase K-resistant tight conformation, whereas the E3 ligase gp78-mediated ERAD-M allowed passage only of nearly completely disordered but not well-folded substrates and thus may have the least unfoldase activity. Vpu-mediated ERAD, containing a potential retrotranslocon, could unfold well-folded substrates for successful retrotranslocation. However, substrate retrotranslocation in Vpu-mediated ERAD was blocked by enhanced conformational tightness of the substrate. On the basis of these findings, we propose a mechanism underlying polypeptide movement through the endoplasmic reticulum membrane. We anticipate that our biochemical system paves the way for identifying the factors necessary for the retrotranslocation of membrane proteins.

Astragaloside IV ameliorates intermittent hypoxia-induced inflammatory dysfunction by suppressing MAPK/NF-κB signalling pathways in Beas-2B cells.

PURPOSE: Intermittent hypoxia is a characteristic pathological change in obstructive sleep apnoea (OSA) that can initiate oxidative stress reaction and pro-inflammatory cytokine release. The purpose of this study was to assess the effect and protective mechanism of Astragaloside IV (AS-IV) in intermittent hypoxia-induced human lung epithelial Beas-2B cells. METHODS: Human lung epithelial Beas-2B cells were exposed to intermittent hypoxia or normoxia in the absence or presence of AS-IV. MTT assay was performed to determine the cell viability. The levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), malonaldehyde (MDA), and superoxide dismutase (SOD) were measured to evaluate oxidative stress. The levels of cytokines interleukin (IL)-8, IL-1ß, and IL-6 were evaluated by enzyme-linked immunosorbent assay and real-time PCR. The expression of Toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear transcription factor-kappa B (NF-κB) signalling pathways was analysed by western blot. RESULTS: The results showed that AS-IV significantly reduced the levels of ROS, LDH, MDA, IL-8, IL-1ß, and IL-6, and increased the level of SOD in intermittent hypoxia-induced Beas-2B cells. It also suppressed the phosphorylation of MAPKs, including P38, c-Jun N-terminal kinase and extracellular signal-regulated kinase, and inhibited the activation of the NF-κB signalling pathway by reducing the phosphorylation of IκBα and p65. CONCLUSIONS: AS-IV attenuates inflammation and oxidative stress by inhibiting TLR4-mediated MAPK/NF-κB signalling pathways in intermittent hypoxia-induced Beas-2B cells.

Regulation of the Oligomeric Status of CCR3 with Binding Ligands Revealed by Single-Molecule Fluorescence Imaging.

The relationship between the oligomeric status and functions of chemokine receptor CCR3 is still controversial. We use total internal reflection fluorescence microscopy at the single-molecule level to visualize the oligomeric status of CCR3 and its regulation of the membrane of stably transfected T-REx-293 cells. We find that the population of the dimers and oligomers of CCR3 can be modulated by the binding of ligands. Natural agonists can induce an increase in the level of dimers and oligomers at high concentrations, whereas antagonists do not have a significant influence on the oligomeric status. Moreover, monomeric CCR3 exhibits a stronger chemotactic response in the migration assay of stably transfected CCR3 cells. Together, these data support the notion that CCR3 exists as a mixture of monomers and dimers under nearly physiological conditions and the monomeric CCR3 receptor is the minimal functional unit in cellular signaling transduction. To the best of our knowledge, these results constitute the first report of the oligomeric status of CCR3 and its regulation.

Functional expression of CCL8 and its interaction with chemokine receptor CCR3.

BACKGROUND: Chemokines and their cognate receptors play important role in the control of leukocyte chemotaxis, HIV entry and other inflammatory diseases. Developing an effcient method to investigate the functional expression of chemokines and its interactions with specific receptors will be helpful to asses the structural and functional characteristics as well as the design of new approach to therapeutic intervention. RESULTS: By making systematic optimization study of expression conditions, soluble and functional production of chemokine C-C motif ligand 8 (CCL8) in Escherichia coli (E. coli) has been achieved with approx. 1.5 mg protein/l culture. Quartz crystal microbalance (QCM) analysis exhibited that the purified CCL8 could bind with C-C chemokine receptor type 3 (CCR3) with dissociation equilibrium constant (K D) as 1.2 × 10-7 M in vitro. Obvious internalization of CCR3 in vivo could be detected in 1 h when exposed to 100 nM of CCL8. Compared with chemokine C-C motif ligand 11 (CCL11) and chemokine C-C motif ligand 24 (CCL24), a weaker chemotactic effect of CCR3 expressing cells was observed when induced by CCL8 with same concentration. CONCLUSION: This study delivers a simple and applicable way to produce functional chemokines in E. coli. The results clearly confirms that CCL8 can interact with chemokine receptor CCR3, therefore, it is promising area to develop drugs for the treatment of related diseases.

High-Density Super-Resolution Localization Imaging with Blinking Carbon Dots.

Molecular fluorescence blinking provides a simple and attractive way to achieve super-resolution localization via conventional fluorescence microscopy. However, success in super-resolution imaging relies heavily on their blinking characteristics. We here report easily prepared and photostable nanoparticles, carbon dots (CDs), with desirable fluorescence blinking for high-density super-resolution imaging. The CDs exhibit a low duty cycle (∼0.003) and high photon output (∼8000) per switching event, as well as show much higher resistance to photobleaching than Alexa 647 or Cy5 typically used in single molecule localization microscopy. The stable blinking of CDs allows to perform high-density localization imaging at a resolution of 25 nm by sequentially recording the particle positions. The CD-based super-resolution imaging is further demonstrated by rendering CD-stained tubular peptide self-assemblies, CD-packed clusters with well-defined patterns, and CD-stained microtubules in a cell. Furthermore, this method has been validated as a valuable tool to detect the clustering and distribution of protein receptors in the plasma membrane that are not discerned with normal fluorescence imaging.

Epb41l3 suppresses esophageal squamous cell carcinoma invasion and inhibits MMP2 and MMP9 expression.

EPB41L3 may play a role as a metastasis suppressor by supporting regular arrangements of actin stress fibres and alleviating the increase in cell motility associated with enhanced metastatic potential. Downregulation of epb41l3 has been observed in many cancers, but the role of this gene in esophageal squamous cell carcinoma (ESCC) remains unclear. Our study aimed to determine the effect of epb41l3 on ESCC cell migration and invasion. We investigated epb41l3 protein expression in tumour and non-tumour tissues by immunohistochemical staining. Expression in the non-neoplastic human esophageal cell line Het-1a and four ESCC cell lines - Kyse150, Kyse510, Kyse450 and Caes17 - was assessed by quantitative Polymerase Chain Reaction (qPCR) and Western blotting. Furthermore, an EPB41L3 overexpression plasmid and EPB41L3-specific small interfering RNA were used to upregulate EPB41L3 expression in Kyse150 cells and to downregulate EPB41L3 expression in Kyse450 cells, respectively. Cell migration and invasion were evaluated by wound healing and transwell assays, respectively. The expression levels of p-AKT, matrix metalloproteinase (MMP)2 and MMP9 were evaluated. Expression of epb41l3 was significantly lower in tumour tissues than in non-tumour tissues and in ESCC cell lines compared with the Het-1a cell line. Kyse450 and Caes17 cells exhibited higher expression of epb41l3 than Kyse150 and Kyse510 cells. Overexpressing epb41l3 decreased Kyse150 cell migration and invasion, whereas EPB41L3-specific small interfering RNA silencing increased these functions in Kyse450 cells. Furthermore, overexpressing epb41l3 led to downregulation of MMP2 and MMP9 in Kyse150 and Kyse510 cells. Our findings reveal that EPB41L3 suppresses tumour cell invasion and inhibits MMP2 and MMP9 expression in ESCC cells.

Conversion of inhibition biosensing to substrate-like biosensing for quinalphos selective detection.

Since all of the organophosphorus pesticides (OPP) inhibit the cholinesterases with a common mechanism, it is still challenging to detect OPP selectively with inhibition-based biosensors. This study focuses on the conversion of a typical inhibition biosensing to a selective substrate-like biosensing. The interaction of quinalphos with plant-esterase involves not only a decrease in enzyme activity but also a heterolytic bond cleavage of quinalphos. The leaving group eliminated from quinalphos is an ideal biomarker due to its specificity in most OPP. Thus, using 2-hydroxyquinoxaline (HQO), the leaving group of quinalphos, as the biomarker and meso-tetra (4-sulfonatophenyl) porphine (TPPS4) as an optical probe, quinalphos can be selectively detected. The molecular recognition between TPPS4 and HQO leads to a considerable sensitivity of the detection. The spectral responses of TPPS4 show a linear dependence on quinalphos concentration in the presence of plant-esterase within the 0.01-1 mg kg(-1) range. The detection limit is 0.01 mg kg(-1), well below the maximum residue limits (MRLs) defined by European Union (0.05 mg kg(-1)) and China (0.2 mg kg(-1)).

LPVS guidance and adaptive event-triggered control for an underactuated surface vessel with the prevention of obstacle's vicious maneuvering.

This paper investigates the adaptive neural event-triggered control for an underactuated surface vessel (USV), considering constraints of the obstacle's vicious maneuvering and the limited communication channel. In the algorithm, a novel logical phantom virtual ship (LPVS) guidance principle is developed to generate the global path following reference and the obstacle avoidance order in the simulation results, where the corresponding operation comply to the suggestion in international regulations for prevention collision at sea (COLREGs). The improved design of velocity obstacle (VO) method can guarantee its predictive capability to prevent the obstacle's vicious maneuvering. As for the control module, the adaptive event-triggered control algorithm is proposed by employing the robust neural damping technique and the input event-triggered mechanism. And the derived adaptive law can effectively solve perturbations from the gain uncertainty and the external disturbances. Through the theoretical analysis, all signals of the closed-loop control system are with the semi-globally uniform ultimate bounded (SGUUB) stability. The simulation experiments have been presented to verify the obstacle avoidance effectiveness and the burden-some superiority of the algorithm.

A Binocular Color Line-Scanning Stereo Vision System for Heavy Rail Surface Detection and Correction Method of Motion Distortion.

Thanks to the line-scanning camera, the measurement method based on line-scanning stereo vision has high optical accuracy, data transmission efficiency, and a wide field of vision. It is more suitable for continuous operation and high-speed transmission of industrial product detection sites. However, the one-dimensional imaging characteristics of the line-scanning camera cause motion distortion during image data acquisition, which directly affects the accuracy of detection. Effectively reducing the influence of motion distortion is the primary problem to ensure detection accuracy. To obtain the two-dimensional color image and three-dimensional contour data of the heavy rail surface at the same time, a binocular color line-scanning stereo vision system is designed to collect the heavy rail surface data combined with the bright field illumination of the symmetrical linear light source. Aiming at the image motion distortion caused by system installation error and collaborative acquisition frame rate mismatch, this paper uses the checkerboard target and two-step cubature Kalman filter algorithm to solve the nonlinear parameters in the motion distortion model, estimate the real motion, and correct the image information. The experiments show that the accuracy of the data contained in the image is improved by 57.3% after correction.

A review on the research progress and application of compressed hydrogen in the marine hydrogen fuel cell power system.

The urgency to mitigate greenhouse gas emissions from maritime vessels has intensified due to the increasingly stringent directives set forth by the International Maritime Organization (IMO). These directives specifically address energy efficiency enhancements and emissions reduction within the shipping industry. In this context, hydrogen is the much sought after fuel for all the global economies and its applications, for transportation and propulsion in particular, is crucial for cutting down carbon emissions. Nevertheless, the realization of hydrogen-powered vessels is confronted by substantial technical hurdles that necessitate thorough examination. This study undertakes a comprehensive analysis encompassing diverse facets, including distinct variations of hydrogen fuel cells, hydrogen internal combustion engines, safety protocols associated with energy storage, as well as the array of policies and commercialization endeavors undertaken globally for the advancement of hydrogen-propelled ships. By amalgamating insights from these multifaceted dimensions, this paper adeptly encapsulates the myriad challenges intrinsic to the evolution of hydrogen-fueled maritime vessels, while concurrently casting a forward-looking gaze on their prospective trajectory.

CT radiomic features reproducibility of virtual non-contrast series derived from photon-counting CCTA datasets using a novel calcium-preserving reconstruction algorithm compared with standard non-contrast series: focusing on epicardial adipose tissue.

PURPOSE: We aimed to evaluate the reproducibility of computed tomography (CT) radiomic features (RFs) about Epicardial Adipose Tissue (EAT). The features derived from coronary photon-counting computed tomography (PCCT) angiography datasets using the PureCalcium (VNCPC) and conventional virtual non-contrast (VNCConv) algorithm were compared with true non-contrast (TNC) series. METHODS: RFs of EAT from 52 patients who underwent PCCT were quantified using VNCPC, VNCConv, and TNC series. The agreement of EAT volume (EATV) and EAT density (EATD) was evaluated using Pearson's correlation coefficient and Bland-Altman analysis. A total of 1530 RFs were included. They are divided into 17 feature categories, each containing 90 RFs. The intraclass correlation coefficients (ICCs) and concordance correlation coefficients (CCCs) were calculated to assess the reproducibility of RFs. The cutoff value considered indicative of reproducible features was > 0.75. RESULTS: the VNCPC and VNCConv tended to underestimate EATVs and overestimate EATDs. Both EATV and EATD of VNCPC series showed higher correlation and agreement with TNC than VNCConv series. All types of RFs from VNCPC series showed greater reproducibility than VNCConv series. Across all image filters, the Square filter exhibited the highest level of reproducibility (ICC = 67/90, 74.4%; CCC = 67/90, 74.4%). GLDM_GrayLevelNonUniformity feature had the highest reproducibility in the original image (ICC = 0.957, CCC = 0.958), exhibiting a high degree of reproducibility across all image filters. CONCLUSION: The accuracy evaluation of EATV and EATD and the reproducibility of RFs from VNCPC series make it an excellent substitute for TNC series exceeding VNCConv series.