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Murine models are employed to probe various aspects of peritoneal dialysis (PD), such as peritoneal inflammation and fibrosis. These events drive peritoneal membrane failure in humans, which remains an area of intense investigation due to its profound clinical implications in managing patients with end-stage kidney disease (ESKD). Despite the clinical importance of PD and its related complications, current experimental murine models suffer from key technical challenges that compromise the models' performance. These include PD catheter migration and kinking and usually warrant earlier catheter removal. These limitations also drive the need for a greater number of animals to complete a study. Addressing these drawbacks, this study introduces technical improvements and surgical nuances to prevent commonly observed PD catheter complications in a murine model. Moreover, this modified model is validated by inducing peritoneal inflammation and fibrosis using lipopolysaccharide injections. In essence, this paper describes an improved method to create an experimental model of PD.

Chronic kidney disease (CKD) imposes a strong and independent risk for peripheral artery disease (PAD). While solutes retained in CKD patients (uremic solutes) inflict vascular damage, their role in PAD remains elusive. Here, we show that the dietary tryptophan-derived uremic solutes including indoxyl sulfate (IS) and kynurenine (Kyn) at concentrations corresponding to those in CKD patients suppress β-catenin in several cell types, including microvascular endothelial cells (ECs), inhibiting Wnt activity and proangiogenic Wnt targets in ECs. Mechanistic probing revealed that these uremic solutes downregulated β-catenin in a manner dependent on serine 33 in its degron motif and through the aryl hydrocarbon receptor (AHR). Hindlimb ischemia in adenine-induced CKD and IS solute–specific mouse models showed diminished β-catenin and VEGF-A in the capillaries and reduced capillary density, which correlated inversely with blood levels of IS and Kyn and AHR activity in ECs. An AHR inhibitor treatment normalized postischemic angiogenic response in CKD mice to a non-CKD level. In a prospective cohort of PAD patients, plasma levels of tryptophan metabolites and plasma’s AHR-inducing activity in ECs significantly increased the risk of future adverse limb events. This work uncovers the tryptophan metabolite/AHR/β-catenin axis as a mediator of microvascular rarefaction in CKD patients and demonstrates its targetability for PAD in CKD models.

Iron can enter the electron-rich cavities of graphitic carbon nitride (g-C3N4). On account of this phenomenon, Fe-doped g-C3N4 (Fe-g-C3N4) was prepared as a peroxidase mimetic by using one-step pyr...

Aberrant hyperactivation of Wnt signaling, driven by nuclear β-catenin in the colonic epithelium, represents the seminal event in the initiation and progression of colorectal cancer (CRC). Despite its established role in CRC tumorigenesis, clinical translation of Wnt inhibitors remains unsuccessful. Late SV40 factor (LSF; encoded by TFCP2) is a transcription factor and a potent oncogene. The current study identified a chemotype, named factor quinolinone inhibitors (FQIs), that specifically inhibits LSF DNA-binding, partner protein-binding, and transactivation activities. The role of LSF and FQIs in CRC tumor growth was examined. Herein, the study showed that LSF and β-catenin interacted in several CRC cell lines irrespective of their mutational profile, which was disrupted by FQI2-34. FQI2-34 suppressed Wnt activity in CRC cells in a dose-dependent manner. Leveraging both allogeneic and syngeneic xenograft models showed that FQI2-34 suppressed CRC tumor growth, significantly reduced nuclear β-catenin, and down-regulated Wnt targets such as axis inhibition protein 2 (AXIN-2) and SRY-box transcription factor 9, in the xenograft cells. FQI2-34 suppressed the proliferation of xenograft cells. Adenocarcinomas from a series of stage IV CRC patients revealed a positive correlation between LSF expression and Wnt targets (AXIN-2 and SRY-box transcription factor 9) within the CRC cells. Collectively, this study uncovers the Wnt inhibitory and CRC growth-suppressive effects of these LSF inhibitors in CRC cells, revealing a novel target in CRC therapeutics.

Kidney injury molecule-1 (KIM-1) staining has been shown to be very useful in identifying acute proximal tubular injury, but its sensitivity, specificity and predicting values for the recovery of renal function after injury in renal biopsies have not been well established. In the first study, we randomly selected 184 renal biopsies from a wide age range of patients (children to elderly) with various renal diseases. KIM-1 staining scores were significantly correlated with serum creatinine (sCr) levels (P

While the worldwide prevalence of kidney disease is increasing rapidly, the current therapeutic repertoire for these patients is often limited to dialysis and organ transplantation. However, advances in developmental and stem cell biology have highlighted the potential of stem cells for the development of novel renal regeneration therapies. While there are currently no approved stem cell-based treatments for kidney disease, various types of stem cells have been shown to facilitate regeneration of kidney tissue in preclinical models of both acute and chronic kidney injury. This review summarises the current status of stem cell-based therapies to battle kidney disease. In addition, future directions for the clinical translation of stem cell research towards development of novel renal regeneration therapies are discussed.

Iminyl radicals have emerged as versatile synthons for N-heterocycle constructions and ring-opening reactions. Iminyl radicals are a special class of N-centered radicals that display unique reactivity, enable H-abstraction to generate more stable carbon radicals, and serve as radical-type electrophiles, thus providing opportunities to explore novel transformations.

The G protein-coupled receptor APJ/Aplnr has been widely reported to be involved in heart and vascular development and disease, but whether it contributes to organ left-right patterning is largely unknown. Here, we show that in zebrafish, aplnra/b coordinates organ LR patterning in an apela/apln ligand-dependent manner using distinct mechanisms at different stages. During gastrulation and early somitogenesis, aplnra/b loss of function results in heart and liver LR asymmetry defects, accompanied by disturbed KV/cilia morphogenesis and disrupted left-sided Nodal/spaw expression in the LPM. In this process, only aplnra loss of function results in KV/cilia morphogenesis defect. In addition, only apela works as the early endogenous ligand to regulate KV morphogenesis, which then contributes to left-sided Nodal/spaw expression and subsequent organ LR patterning. The aplnra-apela cascade regulates KV morphogenesis by enhancing the expression of foxj1a, but not fgf8 or dnh9, during KV development. At the late somite stage, both aplnra and aplnrb contribute to the expression of lft1 in the trunk midline but do not regulate KV formation, and this role is possibly mediated by both endogenous ligands, apela and apln. In conclusion, our study is the first to identify a role for aplnra/b and their endogenous ligands apela/apln in LR patterning, and it clarifies the distinct roles of aplnra-apela and aplnra/b-apela/apln in orchestrating organ LR patterning.

An efficient and “green” protocol for the synthesis of 3-acylimidazo[1,2-a]pyridines through intramolecular oxidative α-amination of carbonyl compounds has been developed. The reaction proceeds smoothly utilizing I2 as a catalyst and H2O2 as an oxidant under neat condition with broad substrate scope. Several complex nitrogen-containing fused rings are conveniently constructed, which are not easy to access by traditional methods.

There is currently no technique to unambiguously diagnose antemortem kidney injury on postmortem examination since postmortem tissue damage and autolysis are common. We assessed the ability to detect kidney injury molecule-1 (KIM-1) expression in adult and fetal kidneys examined at autopsy. In adult kidneys ( n = 52 subjects), we found that the intensity of KIM-1 staining significantly correlated with the antemortem level of serum creatinine, and this was independent of the extent of tissue autolysis. In addition, kidneys from a total of 52 fetal/neonatal subjects, 30 stillborns and 22 liveborns, were assessed for KIM-1 staining. Given that serum creatinine is unreliable and often unavailable in fetuses and newborns, we assessed preterminal hypoxia in fetuses by the presence of squames in pulmonary alveoli and by required intubation. KIM-1 expression correlated with these clinical indexes of hypoxia. The expression of KIM-1 was seen in a majority of the fetal and neonatal autopsy kidneys (77%, 40/52) as early as 16 wk of gestation, even in the presence of autolysis. Thus KIM-1 is a specific and stable marker of antemortem tubular injury in kidneys of adults and fetuses despite postmortem autolysis.

Most reports on oblique plane microscopy (OPM) have a limited microscopic field of view (FOV), typically within 1x1 mm2. We implemented an optical design of mesoscopic scanning oblique plane microscopy (OPM) to allow using low numerical aperture (NA) objective lens. The angle of the intermediate image before the remote focusing system was increased by a demagnification under Scheimpflug condition such that the light collecting efficiency in the remote focusing system was significantly improved. We demonstrate a mesoscopic FOV up to ~6× 5×0.6 mm3 volumetric imaging, the largest reported FOV by OPM so far.

BACKGROUND: Conventional light sheet fluorescence microscopy (LSFM), or selective plane illumination microscopy (SPIM), enables high-resolution 3D imaging over a large volume by using two orthogonally aligned objective lenses to decouple excitation and emission. The recent development of oblique plane microscopy (OPM) simplifies LSFM design with only one single objective lens, by using off-axis excitation and remote focusing. However, most reports on OPM have a limited microscopic field of view (FOV), typically within 1×1 mm(2). Our goal is to overcome the limitation with a new variant of OPM to achieve a mesoscopic FOV. METHODS: We implemented an optical design of mesoscopic scanning OPM to allow the use of low numerical aperture (NA) objective lenses. The angle of the intermediate image before the remote focusing system was increased by a demagnification under Scheimpflug condition such that the light collecting efficiency in the remote focusing system was significantly improved. A telescope composed of cylindrical lenses was used to correct the distorted image caused by the demagnification design. We characterized the 3D resolutions and imaging volume by imaging fluorescent microspheres, and demonstrated the volumetric imaging on intact whole zebrafish larvae, mouse cortex, and multiple Caenorhabditis elegans (C. elegans). RESULTS: We demonstrate a mesoscopic FOV up to ~6×5×0.6 mm(3) volumetric imaging, the largest reported FOV by OPM so far. The angle of the intermediate image plane is independent of the magnification as long as the size of the pupil aperture of the objectives is the same. As a result, the system is highly versatile, allowing simple switching between different objective lenses with low (10×, NA 0.3) and median NA (20×, NA 0.5). Detailed microvasculature in zebrafish larvae, mouse cortex, and neurons in C. elegans are clearly visualized in 3D. CONCLUSIONS: The proposed mesoscopic scanning OPM allows using low NA objectives such that centimeter-level FOV volumetric imaging can be achieved. With the extended FOV, simple sample mounting protocol, and the versatility of changeable FOVs/resolutions, our system will be ready for the varieties of applications requiring in vivo volumetric imaging over large length scales.

BACKGROUND: Endothelial cell injury is a common nidus of renal injury in patients and consistent with the high prevalence of AKI reported during the coronavirus disease 2019 pandemic. This cell type expresses integrin α5 (ITGA5), which is essential to the Tie2 signaling pathway. The microRNA miR-218-5p is upregulated in endothelial progenitor cells (EPCs) after hypoxia, but microRNA regulation of Tie2 in the EPC lineage is unclear. METHODS: We isolated human kidney-derived EPCs (hkEPCs) and surveyed microRNA target transcripts. A preclinical model of ischemic kidney injury was used to evaluate the effect of hkEPCs on capillary repair. We used a genetic knockout model to evaluate the effect of deleting endogenous expression of miR-218 specifically in angioblasts. RESULTS: After ischemic in vitro preconditioning, miR-218-5p was elevated in hkEPCs. We found miR-218-5p bound to ITGA5 mRNA transcript and decreased ITGA5 protein expression. Phosphorylation of 42/44 MAPK decreased by 73.6% in hkEPCs treated with miR-218-5p. Cells supplemented with miR-218-5p downregulated ITGA5 synthesis and decreased 42/44 MAPK phosphorylation. In a CD309-Cre/miR-218-2-LoxP mammalian model (a conditional knockout mouse model designed to delete pre-miR-218-2 exclusively in CD309(+) cells), homozygotes at e18.5 contained avascular glomeruli, whereas heterozygote adults showed susceptibility to kidney injury. Isolated EPCs from the mouse kidney contained high amounts of ITGA5 and showed decreased migratory capacity in three-dimensional cell culture. CONCLUSIONS: These results demonstrate the critical regulatory role of miR-218-5p in kidney EPC migration, a finding that may inform efforts to treat microvascular kidney injury via therapeutic cell delivery.

We implemented a novel optical design to allow using low numerical aperture objective lens in OPM and achieved centimeter-scale volumetric imaging. It has great potential in large specimen imaging such as whole-brain imaging of mice.

As the COVID-19 pandemic continues to spread, investigating the processes underlying the interactions between SARS-CoV-2 and its hosts is of high importance. Here, we report the identification of CD209L/L-SIGN and the related protein CD209/DC-SIGN as receptors capable of mediating SARS-CoV-2 entry into human cells. Immunofluorescence staining of human tissues revealed prominent expression of CD209L in the lung and kidney epithelia and endothelia. Multiple biochemical assays using a purified recombinant SARS-CoV-2 spike receptor-binding domain (S-RBD) or S1 encompassing both N termal domain and RBD and ectopically expressed CD209L and CD209 revealed that CD209L and CD209 interact with S-RBD. CD209L contains two N-glycosylation sequons, at sites N92 and N361, but we determined that only site N92 is occupied. Removal of the N-glycosylation at this site enhances the binding of S-RBD with CD209L. CD209L also interacts with ACE2, suggesting a role for heterodimerization of CD209L and ACE2 in SARS-CoV-2 entry and infection in cell types where both are present. Furthermore, we demonstrate that human endothelial cells are permissive to SARS-CoV-2 infection, and interference with CD209L activity by a knockdown strategy or with soluble CD209L inhibits virus entry. Our observations demonstrate that CD209L and CD209 serve as alternative receptors for SARS-CoV-2 in disease-relevant cell types, including the vascular system. This property is particularly important in tissues where ACE2 has low expression or is absent and may have implications for antiviral drug development., In human endothelial cells, CD209L acts as a receptor for SARS-CoV-2; together with ACE2, it can function as a co-receptor. Blocking CD209L activity inhibited virus entry, indicating a novel target for development of antiviral drugs.

Conventional light sheet fluorescence microscopy (LSFM), or selective plane illumination microscopy (SPIM), enables high resolution 3D imaging over a large volume by using two orthogonally aligned objective lenses to decouple excitation and emission. The recent development of oblique plane microscopy (OPM) simplifies LSFM design with only one single objective lens, by using off-axis excitation and remote focusing. However, most reports on OPM has a limited microscopic field of view (FOV), typically within 1×1 mm2. Our goal is to overcome the limitation with a new variant of OPM to achieve mesoscopic FOV. We implemented an optical design of mesoscopic scanning OPM to allow using low numerical aperture (NA) objective lens. The angle of the intermediate image before the remote focusing system was increased by a demagnification under Scheimpflug condition such that the light collecting efficiency in the remote focusing system was significantly improved. We characterized the 3D resolutions and FOV by imaging fluorescence microspheres, and demonstrated the volumetric imaging on intact whole zebrafish larvae, mouse cortex, and multipleCaenorhabditis elegans (C.elegans). We demonstrate a mesoscopic FOV up to ~6× 5×0.6 mm3volumetric imaging, the largest reported FOV by OPM so far. The angle of the intermediate image plane is independent of the magnification. As a result, the system is highly versatile, allowing simple switching between different objective lenses with low (10x, NA 0.3) and median NA (20x, NA 0.5). Detailed microvasculature in zebrafish larvae, mouse cortex, and neurons inC. elegansare clearly visualized in 3D. The proposed mesoscopic scanning OPM allows using low NA objective such that centimeter-level FOV volumetric imaging can be achieved. With the extended FOV, simple sample mounting protocol, and the versatility of changeable FOVs/resolutions, our system will be ready for the varieties of applications requiringin vivovolumetric imaging over large length scales.

With the increasing demand for security in industrial control systems, many researchers are studying industrial control systems for anomaly detection. Most of them use machine learning method to analyze and predict the traffic, but it is not enough to study the periodic characteristics of the industrial control system. This paper analyzes and studies the characteristics of the protocol field by extracting the unique protocol Modbus in the industrial control system. In this paper, the periodic characteristics of industrial control data are mined from the aspects of symbol sequence. We simulate traffic and test the proposed method which shows that it can effectively detect the periodicity of different sequences in the industrial control system and provide an auxiliary method for anomaly detection.

With the emerging routing planning issues in Power Line Communication networks, the development of routing strategy in PLC networks is increasingly important. Because of the channel noise and attenuation, it is necessary to consider the delay of transmission in PLC networks. To reduce the delay of PLC networks under reliability, we design a routing selecting algorithm while meeting the energy consumption limitation of the PLC networks and reducing the average transmission delay. Simulation results show that this strategy can achieve low transmission delay, and improve the overall performance of the network.

This work aimed to analyse the damaging effects of pulsed electric fields on Rhizoctonia solani. Design Expert software was used to design an orthogonal experiment. The cell membrane damage and cell wall damage were observed by scanning electron microscopy and quantitatively determined while using a conductivity metre and an ultraviolet spectrophotometer. The results showed that the cell membrane damage rate was correlated with the voltage amplitude and processing time (p &lt, 0.01), while the effect of pulse duration was not significant (p &gt, 0.05). Besides, the cell wall damage was related to electric field strength (voltage amplitude) (p &lt, 0.01), while the pulse duration and processing time had no significant effect on that (p &gt, 0.05). The optimal process parameters for this method were 25 kV/cm, 5 min., and a pulse duration of 60 &micro, s. The optimised conditions were tested based on these results. When compared with Control Check (CK), the cell membrane damage rate was 48.72%, which was significantly higher than CK (p &lt, 0.01).

Herein, we developed a simple and rapid colorimetric assay for the detection of melamine using gelatin-coated cerium oxide (Gel-CeO2) nanospheres as peroxidase mimics. Highly monodisperse Gel-CeO2 nanospheres were synthesized through a microwave-assisted hydrothermal process. The Gel-CeO2 nanospheres showed excellent peroxidase activity, which can catalyze the oxidation of ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) by H2O2, resulting in the formation of blue oxidation products. In the presence of melamine, H2O2 will react with melamine through strong hydrogen-bonding. With the consumption of H2O2, the catalytic reaction was interrupted and the blue ABTS oxidation product solution turned pale. There was a linear relationship between the absorbance intensity of the ABTS oxidation product and the logarithm values of melamine concentrations ranging from 50 nM to 5.0 mM. Moreover, the detection limit (S/N = 3) was 5.5 nM, which is far below the regulatory level. This method was simple, rapid, sensitive and reliable, suggesting the promising practical usage of this sensing system. Finally, this method was applied to melamine detection in milk and milk powder.

An efficient and green protocol for the synthesis of acylated imidazo[1,2-a]pyridines and indolizines via intramolecular dehydrogenative aminooxygenation of alkynes has been developed. The reaction proceeds smoothly utilizing I2 as a catalyst and TBHP as an oxidant with a broad substrate scope. Mechanism studies reveal that the reaction maybe experiences a hydration followed by an oxidative cycloamination process.

Surface shape feature is a very important index of seed classification. A method to calculate the three dimensional characteristics of the rice seed based on its surface point cloud was investigated. First of all, a laser scanner was used to acquire the three dimensional point cloud (TDPC) of a rice seed, then based on the principal component analysis (PCA) the TDPC were translated and rotated to normalize coordinate system. The length, width and thickness of rice seed, and furthermore its elongation, flakiness, shape factor and sphericity could be calculated by the oriented bounding box (OBB). We can generate mesh surface of the rice seed surface point cloud by the greedy triangulation algorithm, then calculate the surface area of the rice seed. On the basis of the slice method, an improved method based on rice seed TDPC was proposed to calculate the volume of rice seed. Compare the calculated length, width thickness and volume of different rice seeds with manual measurement. It is found that the average error is less than 1.5%. A ball whose radius is known instead of a rice seed to be used to verify the validity of the surface area by comparing the calculated value with their theoretical value, the mean error is 0.55%. The results showed the calculation method could acquire the surface shape feature of rice seed based on the TDPC and it is valid enough for application, this method is applicable for measurement of other irregular object as well.

This paper adopts the Design-Expert software to design an orthogonal experiment with a pulse voltage amplitude of 30 kV, processing time of three minutes, and a pulse width of 45 &mu, s as the center points, in order to study the effects of the pulsed electric field on the cell wall and infection activity of Rhizoctonia solani. High-voltage pulse power was used to treat the bacteria solution with the pulsed electric field. Untreated Rhizoctonia solani were used as the control group. Transmission electron microscope images were used to analyze the cell wall damage. ANOVA was performed on the experimental results and the fitting degree of the model was good (F&gt, &gt, 1). Response surface analysis was used to optimize the parameters based on chitin content and polygalacturonase activity. The optimal treatment conditions were obtained as a pulse voltage amplitude of 25 kV, processing time of 2.54 min, and a pulse width of 34.35 &mu, s. On this basis, experiments were designed to verify the optimized conditions. The results demonstrated that, under the optimal processing conditions, the damage index of the cell wall of Rhizoctonia solani was 9.59% lower in chitin content and 83.05% lower in polygalacturonase activity compared with those of the control group. All indexes were significantly different (P &lt, 0.001), which is consistent with the parameter optimization results. The results provide a theoretical basis for the pulsed electric field assisted sterilization and reference for the design of plant protection machinery in the latter stage.

This article studies the sterilization effects of high-voltage pulsed electric field (PEF) of technology on filamentous fungi. A cell dielectric model was proposed based on the physical structure of filamentous fungi. Basic theories of the electromagnetic field were comprehensively applied, and the multiphysics field simulation software COMSOL Multiphysics was used for more detailed study. The effects of PEF treatment parameters and microbial characteristic parameters on the resulting cell membrane and nuclear membrane changes were simulated and analyzed. The results showed significant effects on the transmembrane voltage of the cell membrane and nuclear membrane from the electric field intensity, pulse duration, cell membrane thickness, superposition effect of the pulses. However, the amount of hyphae had little effect, and the number of cell nuclei and the thickness of the cell walls had almost no effect on the transmembrane voltage of the cell membranes and the nuclear membranes. The results provide theoretical support for applying high-voltage PEFs to kill fungi in practical applications.

Introduction: Catheter-related blood stream infection (CRBSI), the most common complication of central vein catheter (CVC), was closely associated with high morbidity and mortality in hemodialysis (HD) patients. Conjunction with systemic antibiotic, antibiotic lock (ABL) is an important therapeutic option to salvage the catheter. With extra antimicrobial and biofilm removing properties, urokinase plasminogen activator (uPA)-based ABL could have a potential role in the treatment of CRBSI. Objective: In this study, we aimed to explore effectiveness of uPA-based (ABL) on microorganisms embedded in biofilms in vitro and CVC salvage rate in HD patients with CRBSI. Methods: In vitro, we induced biofilms formation on the surface of HD catheter by mimicking the development of CRBSI. Applying uPA with or without antibiotics on the kinds of microorganism biofilms to explore its antimicrobial and biofilm removing properties. In vivo, 86 HD patients diagnosed as CRBSI were retrospectively enrolled to see effectiveness of uPA-based ABL on catheter salvage rate as compare to heparin-based ABL. Results: uPA was effect to Staphylococcus epidermidis biofilms compared to Staphylococcus aureus, Escherichia coli, and Candida albicans. Less biofilm residues made the regrowth of S. epidermidis also limited. The combination of uPA with antibiotic showed better antimicrobial and antibiofilm activity than uPA alone or heparin-based ABL in vitro and in vivo. Among HD patients, uPA-based ABL did not cause any obvious adverse affects, and it was more effective in treating coagulase-negative Staphylococci related CRBSI than other microorganisms. Conclusions: The combination of uPA and a therapeutic plasma concentration of sensitive antibiotic can work together to effectively remove coagulase-negative S. epidermidis embedded in biofilms in vitro. uPA-based ABL is safe and effective therapeutic intervention for HD patients with CRBSI, especially compared to heparin-based ABL.

Casitas B lymphoma (c-Cbl) is an E3 ubiquitin ligase and a negative regulator of colorectal cancer (CRC). Despite its high expression in immune cells, the effect of c-Cbl on the tumor microenvironment remains poorly understood. Here we demonstrate that c-Cbl alters the tumor microenvironment and suppresses Programmed cell death-1 (PD-1) protein, an immune checkpoint receptor. Using syngeneic CRC xenografts, we observed significantly higher growth of xenografts and infiltrating immune cells in c-Cbl+/− compared to c-Cbl+/+ mice. Tumor-associated CD8+ T-lymphocytes and macrophages of c-Cbl+/− mice showed 2–3-fold higher levels of PD-1. Functionally, macrophages from c-Cbl+/− mice showed a 4–5-fold reduction in tumor phagocytosis, which was restored with an anti-PD-1 neutralizing antibody suggesting regulation of PD-1 by c-Cbl. Further mechanistic probing revealed that C-terminus of c-Cbl interacted with the cytoplasmic tail of PD-1. c-Cbl destabilized PD-1 through ubiquitination- proteasomal degradation depending on c-Cbl’s RING finger function. This data demonstrates c-Cbl as an E3 ligase of PD-1 and a regulator of tumor microenvironment, both of which were unrecognized components of its tumor suppressive activity. Advancing immune checkpoint and c-Cbl biology, our study prompts for probing of PD-1 regulation by c-Cbl in conditions driven by immune checkpoint abnormalities such as cancers and autoimmune diseases.