Systemic loss of CD36 aggravates NAFLD-related HCC through MEK1/2-ERK1/2 signaling pathway.

BACKGROUND & AIMS: CD36, a membrane protein widely present in various tissues, is crucial role in regulating energy metabolism. The rise of HCC as a notable outcome of NAFLD is becoming more apparent. Patients with hereditary CD36 deficiency are at increased risk of NAFLD. However, the impact of CD36 deficiency on NAFLD-HCC remains unclear. METHODS: Global CD36 knockout mice (CD36KO) and wild type mice (WT) were induced to establish NAFLD-HCC model by N-nitrosodiethylamine (DEN) plus high fat diet (HFD). Transcriptomics was employed to examine genes that were expressed differentially. RESULTS: Compared to WT mice, CD36KO mice showed more severe HFD-induced liver issues and increased tumor malignancy. The MEK1/2-ERK1/2 pathway activation was detected in the liver tissues of CD36KO mice using RNA sequencing and Western blot analysis. CONCLUSION: Systemic loss of CD36 leaded to the advancement of NAFLD to HCC by causing lipid disorders and metabolic inflammation, a process that involves the activation of MAPK signaling pathway. We found that CD36 contributes significantly to the maintenance of metabolic homeostasis in NAFLD-HCC.

Characterization of glomerular basement membrane components within pediatric glomerular diseases.

Background: Disruptions in gene expression associated with the glomerular basement membrane (GBM) could precipitate glomerular dysfunction. Nevertheless, a comprehensive understanding of the characterization of GBM components within pediatric glomerular diseases and their potential association with glomerular function necessitates further systematic investigation. Methods: We conducted a systematic analysis focusing on the pathological transformations and molecular attributes of key constituents within the GBM, specifically Collagen IV α3α4α5, Laminin α5ß2γ1, and Integrin α3ß1, across prevalent pediatric glomerular diseases. Results: We observed upregulation of linear expression levels of COL4A3/4/5 and Laminin 5α proteins, along with a partial reduction in the linear structural expression of Podocin in idiopathic nephrotic syndrome (INS), encompassing minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS), but showing a reduction in IgA nephropathy (IgAN), IgA vasculitis nephritis (IgAVN) and lupus nephritis (LN). Furthermore, our study revealed reductions in Laminin ß2γ1 and Integrin α3ß1 in both primary and secondary childhood glomerular diseases. Conclusion: In INS, notably MCD and FSGS, there is a notable increase in the linear expression levels of COL4A3/4/5 and Laminin 5α proteins. In contrast, in IgAN, IgAVN, and LN, there is a consistent reduction in the expression of these markers. Furthermore, the persistent reduction of Laminin ß2γ1 and Integrin α3ß1 in both primary and secondary childhood glomerular diseases suggests a shared characteristic of structural alterations within the GBM across these conditions.

Dual-monomer solvatochromic probe system (DSPS) for effectively differentiating lipid raft cholesterol and active membrane cholesterol in the inner-leaflet plasma membrane.

Monitoring active membrane cholesterol and lipid raft cholesterol in the inner leaflet of the plasma membrane is significant for understanding the membrane function and cellular physiopathological processes. Limited by existing methods, it is difficult to differentiate active membrane cholesterol and lipid raft cholesterol. A novel dual-monomer solvatochromic probe system (DSPS) that targets two types of cholesterol was developed. Acrylodan-BG/SNAP-D4 composed of SNAP-D4 cholesterol-recognizing monomers and solvatochromic acrylodan-BG-sensing monomers exhibits excellent cholesterol detecting properties in terms of selectivity, accuracy, convenience and economic benefits. Cell imaging revealed that lipid raft cholesterol emitted blue fluorescence, whereas active membrane cholesterol (which partially bobbed in aqueous cytosol) displayed green fluorescence; both the fluorescence emissions increased or decreased in a cholesterol-dependent manner. This system provides a new technology for the determination of two types of cholesterol, which is beneficial for the further study of membrane function, intracellular cholesterol trafficking, and cell signaling.

Klotho inhibits renal ox-LDL deposition via IGF-1R/RAC1/OLR1 signaling to ameliorate podocyte injury in diabetic kidney disease.

OBJECTIVE: Diabetic kidney disease (DKD) is characterized by the abnormal deposition of oxidized low-density lipoprotein (ox-LDL), which contributes to podocyte damage. Klotho, an aging suppressor that plays a critical role in protecting podocytes in DKD, is mainly expressed in kidney tubular epithelium and secreted in the blood. However, it has not been established whether Klotho can alleviate podocyte injury by inhibiting renal ox-LDL deposition, and the potential molecular mechanisms require further investigation. METHODS: We conducted a comprehensive analysis of serum and kidney biopsy samples obtained from patients diagnosed with DKD. Additionally, to explore the underlying mechanism of Klotho in the deposition of ox-LDL in the kidneys, we employed a mouse model of DKD with the Klotho genotype induced by streptozotocin (STZ). Furthermore, we conducted meticulous in vitro experiments on podocytes to gain further insights into the specific role of Klotho in the deposition of ox-LDL within the kidney. RESULTS: Our groundbreaking study unveiled the remarkable ability of the soluble form of Klotho to effectively inhibit high glucose-induced ox-LDL deposition in podocytes affected by DKD. Subsequent investigations elucidated that Klotho achieved this inhibition by reducing the expression of the insulin/insulin-like growth factor 1 receptor (IGF-1R), consequently leading to a decrease in the expression of Ras-related C3 botulinum toxin substrate 1 (RAC1) and an enhancement of mitochondrial function. Ultimately, this series of events culminated in a significant reduction in the expression of the oxidized low-density lipoprotein receptor (OLR1), thereby resulting in a notable decrease in renal ox-LDL deposition in DKD. CONCLUSION: Our findings suggested that Klotho had the potential to mitigate podocyte injury and reduced high glucose-induced ox-LDL deposition in glomerulus by modulating the IGF-1R/RAC1/OLR1 signaling. These results provided valuable insights that could inform the development of novel strategies for diagnosing and treating DKD.

Peripheral Inflammatory Factors and Acute Myocardial Infarction Risk: A Mendelian Randomization Study.

Background: Previous observational studies have confirmed the relationship between inflammation and acute myocardial infarction (AMI), but genetic evidence is still lacking. The aim of this study was to explore the bidirectional association of multiple peripheral inflammatory factors with this disease at the genetic level. Methods: Summary data for AMI and several peripheral inflammatory factors (such as interleukin-10 and interleukin-18) were collected from published genome-wide correlation studies. Based on the correlation, independence, and exclusivity assumptions, a total of 9 to 110 instrumental variables were selected from these summary data to predict the above traits. Two-sample Mendelian randomization methods, including inverse-variance weighted (IVW), were used to make causal inferences between exposures and outcomes. Sensitivity analyses including Cochran's Q, MR-Egger intercept, leave-one-out, forest plot, and MR-PRESSO were adopted to assess heterogeneity and horizontal pleiotropy. Results: The IVW reported that elevated peripheral levels of interleukin-10 and interleukin-18 were nominally associated with a reduced risk of AMI (OR = 0.876, 95% CI = 0.788 ~ 0.974, P = 0.015; OR = 0.934, 95% CI = 0.875 ~ 0.997, P = 0.040). The IVW also reported that the risk of AMI nominally increased the peripheral level of interleukin-10 (OR = 1.062, 95% CI = 1.003 ~ 1.124, P = 0.040). No significant heterogeneity or horizontal pleiotropy were found by sensitivity analyses. Conclusion: Both interleukin-10 and interleukin-18 were peripheral inflammatory factors genetically associated with AMI. In particular, combined with previous knowledge, interleukin-10 may have a protective effect on the onset, progression, and prognosis of the disease.

Tislelizumab vs Sorafenib as First-Line Treatment for Unresectable Hepatocellular Carcinoma: A Phase 3 Randomized Clinical Trial.

Importance: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality, and additional first-line treatments are needed. The programmed cell death protein 1 inhibitor tislelizumab demonstrated efficacy and a tolerable safety profile as second-line HCC treatment. Objective: To investigate efficacy and safety of tislelizumab vs sorafenib tosylate for first-line treatment of unresectable HCC. Design, Setting, and Participants: The open-label, global, multiregional phase 3 RATIONALE-301 randomized clinical trial enrolled systemic therapy-naive adults with histologically confirmed HCC, Barcelona Clinic Liver Cancer stage B or C disease, disease progression following (or patient was not amenable to) locoregional therapy, Eastern Cooperative Oncology Group performance status of 1 or less, and Child-Pugh class A, between December 27, 2017, and October 2, 2019. Data cutoff was July 11, 2022. Intervention: Patients were randomized 1:1 to receive tislelizumab, 200 mg intravenously every 3 weeks, or sorafenib tosylate, 400 mg orally twice daily. Main Outcomes and Measures: The primary end point was overall survival (OS); secondary end points included objective response rate, progression-free survival, duration of response, and safety. Results: A total of 674 patients were included in the analysis (570 men [84.6%]; median age, 61 years [range, 23-86 years]). As of July 11, 2022, minimum study follow-up was 33 months. The primary end point of OS noninferiority of tislelizumab vs sorafenib was met in the intention-to-treat population (n = 674); median overall survival was 15.9 (95% CI, 13.2-19.7) months vs 14.1 (95% CI, 12.6-17.4) months, respectively (hazard ratio [HR], 0.85 [95.003% CI, 0.71-1.02]), and superiority of tislelizumab vs sorafenib was not met. The objective response rate was 14.3% (n = 49) for tislelizumab vs 5.4% (n = 18) for sorafenib, and median duration of response was 36.1 (95% CI, 16.8 to not evaluable) months vs 11.0 (95% CI, 6.2-14.7) months, respectively. Median progression-free survival was 2.1 (95% CI, 2.1-3.5) months vs 3.4 (95% CI, 2.2-4.1) months with tislelizumab vs sorafenib (HR, 1.11 [95% CI, 0.92-1.33]). The incidence of treatment-emergent adverse events (AEs) was 96.2% (325 of 338 patients) for tislelizumab and 100% (n = 324) for sorafenib. Grade 3 or greater treatment-related AEs were reported in 75 patients (22.2%) receiving tislelizumab and 173 (53.4%) receiving sorafenib. There was a lower incidence of treatment-related AEs leading to drug discontinuation (21 [6.2%] vs 33 [10.2%]) and drug modification (68 [20.1%] vs 187 [57.7%]) with tislelizumab vs sorafenib. Conclusions and Relevance: In RATIONALE-301, tislelizumab demonstrated OS benefit that was noninferior vs sorafenib, with a higher objective response rate and more durable responses, while median progression-free survival was longer with sorafenib. Tislelizumab demonstrated a favorable safety profile vs sorafenib. Trial Registration: ClinicalTrials.gov Identifier: NCT03412773.

CT-based radiomic phenotypes of lung adenocarcinoma: a preliminary comparative analysis with targeted next-generation sequencing.

Objectives: This study aimed to explore the relationship between computed tomography (CT)-based radiomic phenotypes and genomic profiles, including expression of programmed cell death-ligand 1 (PD-L1) and the 10 major genes, such as epidermal growth factor receptor (EGFR), tumor protein 53 (TP53), and Kirsten rat sarcoma viral oncogene (KRAS), in patients with lung adenocarcinoma (LUAD). Methods: In total, 288 consecutive patients with pathologically confirmed LUAD were enrolled in this retrospective study. Radiomic features were extracted from preoperative CT images, and targeted genomic data were profiled through next-generation sequencing. PD-L1 expression was assessed by immunohistochemistry staining (chi-square test or Fisher's exact test for categorical data and the Kruskal-Wallis test for continuous data). A total of 1,013 radiomic features were obtained from each patient's CT images. Consensus clustering was used to cluster patients on the basis of radiomic features. Results: The 288 patients were classified according to consensus clustering into four radiomic phenotypes: Cluster 1 (n = 11) involving mainly large solid masses with a maximum diameter of 5.1 ± 2.0 cm; Clusters 2 and 3 involving mainly part-solid and solid masses with maximum diameters of 2.1 ± 1.4 cm and 2.1 ± 0.9 cm, respectively; and Cluster 4 involving mostly small ground-glass opacity lesions with a maximum diameter of 1.0 ± 0.9 cm. Differences in maximum diameter, PD-L1 expression, and TP53, EGFR, BRAF, ROS1, and ERBB2 mutations among the four clusters were statistically significant. Regarding targeted therapy and immunotherapy, EGFR mutations were highest in Cluster 2 (73.1%); PD-L1 expression was highest in Cluster 1 (45.5%). Conclusion: Our findings provide evidence that CT-based radiomic phenotypes could non-invasively identify LUADs with different molecular characteristics, showing the potential to provide personalized treatment decision-making support for LUAD patients.

Hepatocyte CD36 protects mice from NASH diet-induced liver injury and fibrosis via blocking N1ICD production.

BACKGROUND & AIMS: Fatty acid translocase CD36 (CD36/FAT) is a widely expressed membrane protein with multiple immuno-metabolic functions. Genetic CD36 deficiency is associated with increased risk of metabolic dysfunction-associated fatty liver disease (MAFLD) in patients. Liver fibrosis severity mainly affects the prognosis in patients with MAFLD, but the role of hepatocyte CD36 in liver fibrosis of MAFLD remains unclear. METHODS: A high-fat high-cholesterol diet and a high-fat diet with high-fructose drinking water were used to induce nonalcoholic steatohepatitis (NASH) in hepatocyte-specific CD36 knockout (CD36LKO) and CD36flox/flox (LWT) mice. Human hepG2 cell line was used to investigate the role of CD36 in regulating Notch pathway in vitro. RESULTS: Compared to LWT mice, CD36LKO mice were susceptible to NASH diet-induced liver injury and fibrosis. The analysis of RNA-sequencing data revealed that Notch pathway was activated in CD36LKO mice. LY3039478, an inhibitor of γ-secretase, inhibited Notch1 protein S3 cleavage and Notch1 intracellular domain (N1ICD) production, alleviating liver injury and fibrosis in CD36LKO mice livers. Likewise, both LY3039478 and knockdown of Notch1 inhibited the CD36KO-induced increase of N1ICD production, causing the decrease of fibrogenic markers in CD36KO HepG2 cells. Mechanistically, CD36 formed a complex with Notch1 and γ-secretase in lipid rafts, and hence CD36 anchored Notch1 in lipid rafts domains and blocked Notch1/γ-secretase interaction, inhibiting γ-secretase-mediated cleavage of Notch1 and the production of N1ICD. CONCLUSIONS: Hepatocyte CD36 plays a key role in protecting mice from diet-induced liver injury and fibrosis, which may provide a potential therapeutic strategy for preventing liver fibrogenesis in MAFLD.

CD36 regulates diurnal glucose metabolism and hepatic clock to maintain glucose homeostasis in mice.

The mammalian circadian clock and glucose metabolism are highly interconnected, and disruption of this coupling is associated with multiple negative health outcomes. Liver is the major source of endogenous glucose production and liver clock is one of the most vital peripheral clock systems. We demonstrate that fatty acid translocase (CD36) is expressed rhythmically in mouse liver and autonomously modulates the diurnal oscillations of liver clock and glucose homeostasis. CD36 knockout in hepatocytes inhibits the relay of insulin signaling and provokes FoxO1 nuclear shuttling, consequently increasing Per1 nuclear expression. Moreover, FoxO1 can activate the central clock gene Per1 at the transcriptional level. These changes lead to a disrupted clock oscillation and behavioral rhythm. Our study first reveal that CD36 is a key regulator of the circadian oscillator and its deficiency may cause liver clock disruption, which aggravates the imbalance of glucose homeostasis and contribute to augmentation and progression of metabolic disease.

Hepatocyte CD36 modulates UBQLN1-mediated proteasomal degradation of autophagic SNARE proteins contributing to septic liver injury.

Macroautophagy/autophagy plays a protective role in sepsis-induced liver injury. As a member of class B scavenger receptors, CD36 plays important roles in various disorders, such as atherosclerosis and fatty liver disease. Here we found that the expression of CD36 in hepatocytes was increased in patients and a mouse model with sepsis, accompanied by impaired autophagy flux. Furthermore, hepatocyte cd36 knockout (cd36-HKO) markedly improved liver injury and the impairment of autophagosome-lysosome fusion in lipopolysaccharide (LPS)-induced septic mice. Ubqln1 (ubiquilin 1) overexpression (OE) in hepatocyte blocked the protective effect of cd36-HKO on LPS-induced liver injury in mice. Mechanistically, with LPS stimulation, CD36 on the plasma membrane was depalmitoylated and distributed to the lysosome, where CD36 acted as a bridge molecule linking UBQLN1 to soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and hence promoting the proteasomal degradation of SNARE proteins, resulting in fusion impairment. Overall, our data reveal that CD36 is essential for modulating the proteasomal degradation of autophagic SNARE proteins in a UBQLN1-dependent manner. Targeting CD36 in hepatocytes is effective for improving autophagic flux in sepsis and therefore represents a promising therapeutic strategy for clinical treatment of septic liver injury.Abbreviations: AAV8: adeno-associated virus 8; AOSC: acute obstructive suppurative cholangitis; ATP1A1: ATPase, Na+/K+ transporting, alpha 1 polypeptide; CASP3: caspase 3; CASP8: caspase 8; CCL2: chemokine (C-C motif) ligand 2; cd36-HKO: hepatocyte-specific cd36 knockout; Co-IP: co-immunoprecipitation; CQ: chloroquine; Cys: cysteine; GOT1: glutamic-oxaloacetic transaminase 1, soluble; GPT: glutamic-pyruvic transaminase, soluble; IL1B: interleukin 1 beta; IL6: interleukin 6; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LDH, lactate dehydrogenase; LPS: lipopolysaccharide; LYPLA1: lysophospholipase 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; OE: overexpression; qPCR: quantitative polymerase chain reaction; SNAP29: synaptosome associated protein 29; SNARE: soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SQSTM1/p62: sequestosome 1; STX17: syntaxin 17; TNF: tumor necrosis factor; TRIM: tripartite motif-containing; UBA: ubiquitin-associated; UBL: ubiquitin-like; UBQLN: ubiquilin; VAMP8: vesicle associated membrane protein 8; WT: wild-type.

SCAP contributes to embryonic angiogenesis by negatively regulating KISS-1 expression in mice.

Sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) is indispensable in organ development because it maintains intracellular cholesterol homeostasis. The vessel is not widely conceived of as a cholesterol-sensitive tissue, so the specific role of SCAP in angiogenesis has not been paid attention to. As an important component of the vascular mesoderm, vascular smooth muscle cells (VSMCs) are widely involved in each step of angiogenesis. Here, we report for the first time that VSMC-specific ablation of SCAP inhibits VSMC proliferation and migration, interacting with endothelial cells (ECs), and finally causes defective embryonic angiogenesis in mice. Mechanistically, we demonstrated that SCAP ablation in VSMCs leads to the upregulation of KISS-1 protein, consequently resulting in suppressed activation of the MAPK/ERK signaling pathway and downregulation of matrix metalloproteinase 9 (MMP9) and vascular endothelial-derived growth factor (VEGF) expression to prevent angiogenesis. Importantly, we found that SCAP promotes the cleavage and nuclear translocation of SREBP2, which acts as a negative transcription regulator, regulating KISS-1 expression. Our findings suggest that SCAP contributes to embryonic angiogenesis by negatively regulating KISS-1 expression in mice and provide a new point of view for therapeutic targets of vascular development.

Loss of Splicing Factor SRSF3 Impairs Lipophagy Through Ubiquitination and Degradation of Syntaxin17 in Hepatocytes.

Lipid accumulation in hepatocytes is the distinctive characteristic of nonalcoholic fatty liver disease. Serine/arginine-rich splicing factor 3 (SRSF3) is highly expressed in the liver and expression decreases in high-fat conditions. However, the role of SRSF3 in hepatic lipid metabolism needs to be clarified. Here, we showed that loss of SRSF3 was associated with lipid accumulation. We determined that SRSF3 regulated lipophagy, the process of selective degradation of lipid droplets by autophagy. Mechanistically, loss of SRSF3 impaired the fusion of the autophagosome and lysosome by promoting the proteasomal degradation of syntaxin 17 (STX17), a key autophagosomal SNARE protein. We found that ubiquitination of STX17 was increased and upregulation of seven in absentia homolog 1 was responsible for the increased posttranslational modification of STX17. Taken together, our data primarily demonstrate that loss of SRSF3 weakens the clearance of fatty acids by impairing lipophagy in the progression of nonalcoholic fatty liver disease, indicating a novel potential therapeutic target for fatty liver disease treatment.

A high-impact FN1 variant correlates with fibronectin-mediated glomerulopathy via decreased binding to collagen type IV.

The glomerular basement membrane (GBM) consists of laminins, collagen IV, nidogens, and fibronectin and is essential for filtration barrier integrity in the kidney. Critically, structural and functional abnormalities in the GBM are involved in chronic kidney disease (CKD) occurrence and development. Fibronectin is encoded by FN1 and is essential for podocyte-podocyte and podocyte-matrix interactions. However, disrupted or disordered fibronectin occurs in many kidney diseases. In this study, we identified a novel mutation (c.3415G>A) in FN1 that causes glomerular fibronectin-specific deposition in a gain-of-function manner, that may be associated with thin basement membrane nephropathy (TBMN) and expand the spectrum of phenotypes seen in glomerulopathy with fibronectin deposits (GFND). Our studies confirmed this variant increased fibronectin's ability to bind to integrin, thereby maintaining podocyte adhesion. Also, we hypothesised that TBMN arose as the fibronectin variant exhibited a decreased capacity to bind COL4A3/4. Our study is the first to identify and link this novel pathogenic mutation (c.3415G>A) in FN1 to GFND as well as TBMN, which may broaden the phenotype and mutation spectrums of the FN1 gene. We believe our data will positively impact genetic counselling and prenatal diagnostics for GFND with TBMN and other associated conditions that may be commonly benign conditions in humans, and may not require proteinuria-lowering treatments or renal biopsy.

The compound heterozygous mutations of c.607G>a and c.657delC in the FAH gene are associated with renal damage with hereditary tyrosinemia type 1 (HT1).

BACKGROUND: Hereditary tyrosinemia type 1 (HT1) is a rare inherited metabolic disease characterized by severe liver and renal dysfunction. Early identification in affected children is critical for improved treatment options and prognosis. METHODS: In this study, we identified novel compound heterozygous mutations (NM_000137: c.657delC (p.K220Rfs*12) and c.607G>A (p.A203T)) in the fumarylacetoacetate hydrolase (FAH) gene in a family. We also characterized the clinical phenotype of the proband and verified the pathogenic effects of the mutations. Furthermore, we explored the pathogenic mechanism of renal injury through renal biopsy pathology and cell-based in vitro assays. Our study aims to verify the association between novel fumarylacetoacetate hydrolase (FAH) variants and HT1, confirm the pathogenic effects of the mutations and explore the pathogenic mechanism of renal injury. RESULTS: We showed these FAH mutations were inherited in an autosomal recessive manner and resulted in abnormal FAH protein expression and dysfunction, leading to fumarylacetoacetate (FAA) accumulation. The proband also showed apparent renal injury, including glomerular filtration barrier dysfunction and abnormal tubular protein reabsorption. CONCLUSIONS: These observations may provide deeper insights on disease pathogenesis and identify potential therapeutic approaches for HT1 from a genetic perspective. Similarly, we hope to provide valuable information for genetic counseling and prenatal diagnostics.

CT-based radiomics signature to predict CD8+ tumor infiltrating lymphocytes in non-small-cell lung cancer.

BACKGROUND: An abundance of CD8+ tumor infiltrating lymphocytes (TILs) in the center of solid tumors is a reliable predictive biomarker for patients eligible for immunotherapy. PURPOSE: To develop a computed tomography (CT)-based radiomics signature for a preoperative prediction of an abundance of CD8+ TILs in non-small-cell lung cancer (NSCLC). MATERIAL AND METHODS: In this retrospective study, 117 consecutive patients with pathologically confirmed NSCLC were included and randomly divided into training (n = 77) and test sets (n = 40). A total of 107 radiomics features were extracted from the three-dimensional volumes of interest of each patient. Least absolute shrinkage and selection operator (LASSO) regression was used to select the strongest features for abundance of CD8+ TILs in NSCLC, and the radiomics score was constructed through a linear combination of these selected features. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive performance of the radiomics score. RESULTS: The radiomics score was associated with an abundance of CD8+ TILs in NSCLC, which achieved an area under the curve (AUC) of 0.83 (95% CI=0.73-0.92) and 0.68 (95% CI=0.54-0.87) in the training and test sets, respectively. The difference was not statistically significant (P = 0.20). The tumors with high CD8+ TILs tended to have heterogeneous dependences (high value of Dependence Non-Uniformity Normalized) and complicated texture (high value of Informational Measure of Correlation 1). CONCLUSION: CT-based radiomics features have the ability to predict CD8+ TILs expression levels of an abundance of CD8+ TILs in NSCLC, which was shown to be a potential imaging biomarker for stratifying patients who may benefit from immunotherapy.

Circulating soluble CD36 as a novel biomarker for progression and prognosis of HBV-related liver diseases.

Background: Our previous study suggested CD36 may be a positive regulator of hepatitis B virus (HBV) replication in vitro. Therefore, the present study aimed to investigate whether circulating soluble CD36 (sCD36) could serve as a diagnostic and prognostic biomarker for HBV-related liver diseases based on the clinic collected data. Methods: A total of 282 subjects were divided into healthy controls (HC, n = 47), chronic hepatitis B (CHB, n = 68), HBV-related liver cirrhosis (HBV-LC, n = 167). Soluble CD36 in plasma was measured by ELISA, and monocyte or platelet CD36 expression was determined by flow cytometry. Results: There was a step-wise increase of sCD36 with the progression of chronic HBV infection, and it was the highest in the HBV- LC group with liver failure (1.50, IQR:1.04-2.00) as compared with HC (0.38, IQR:0.27-0.38), CHB (0.75, IQR:0.40-1.13), and HBV-LC without liver failure (1.02, IQR,0.61-1.35) group. Circulating sCD36 was not correlated with serum HBV DNA levels, but correlated with liver function parameters. Additionally, ROC analysis confirmed sCD36 could be used to predict liver failure for HBV-LC patients, which yielded an AUC of 0.775 with 71.0% sensitivity and 72.2% specificity. Multivariate logistic regression analysis revealed sCD36 is an independent risk factor in predicting liver failure. Moreover, plasma sCD36 in HBV-LC patients was significantly correlated with prognostic indices, including MELD, MELD-Na and CHILD-PUGH scores. On the other hand, CD36 expression on monocytes or platelets was positively correlated with plasma sCD36 levels, whereas they were not strongly associated with the disease severity. Conclusion: Circulating sCD36 could be used as a novel noninvasive biomarker for predicting liver failure and prognosis in chronic HBV infected patients.

Novel pathogenic variants in CUBN uncouple proteinuria from renal function.

BACKGROUND: Proteinuria is an unfavorable clinical condition highly associated with a risk of renal and cardiovascular disease in chronic kidney disease (CKD). However, whether all proteinuria forms are linked to renal impairment are still unclear. Cubilin is an endocytic receptor highly expressed in renal proximal tubules mediating uptake of albumin, transferrin and α1-microglobulin. METHODS: Exome sequencing method initially identified candidate genes. With the application of exome sequencing combined with Sanger sequencing, we further focused on CUBN through bioinformatics analysis. The pathogenic effects of the potentially causative variants were verified utilizing complementary analysis of clinical data and systematic characterization of the variants' expression and function with clinical samples and in vitro experiments in HEK293T cell lines along with in vivo experiments in mice. RESULTS: In this study, we identified four novel variants locating after the vitamin B12 (vitB12)-binding domain of Cubilin (encoded by CUBN, NM_001081.3: c.4397G > A (p.C1466Y), c.6796C > T (p.R2266X), c.6821 + 3A > G and c.5153_5154delCT (p.S1718X)) in two families. Moreover, the variants severely affected the expression and function of Cubilin in renal proximal tubules and caused albuminuria, increasing levels in urine transferrin and α1-microglobulin, but without progressive glomerular filtration barrier (GFB) impairment, vitB12 deficiencies or abnormal blood levels of HDL and albumin. Further mechanistic insights showed that the variants after the vitB12-binding domain of CUBN merely disrupted the association with Amnionless (AMN) that exhibited aberrant localization in cell cytoplasm rather than membrane. CONCLUSIONS: Here, our findings suggested that different mutation types after the vitB12-binding domain of CUBN uncouple proteinuria from glomerular filtration barrier, that may be an unexpectedly common benign condition in humans and may not require any proteinuria-lowering treatment or renal biopsy.

Selenoprotein K contributes to CD36 subcellular trafficking in hepatocytes by accelerating nascent COPII vesicle formation and aggravates hepatic steatosis.

SelenoproteinK (SelK), an endoplasmic reticulum (ER) - resident protein, possesses the property of mediate oxidation resistance and ER - associated protein degradation (ERAD) in several tissues. Here, we found that increased SelK markedly promotes fatty acid translocase (CD36) subcellular trafficking and aggravates lipid accumulation in hepatocytes. We demonstrated that SelK is required for the assembly of COPII vesicles and accelerates transport of palmitoylated-CD36 from the ER to Golgi, thus facilitating CD36 plasma membrane distribution both in vivo and in vitro. The mechanism is that SelK increases the stability of Sar1B and triggers CD36-containing nascent COPII vesicle formation, consequently, promotes CD36 subcellular trafficking. Furthermore, we verified that the intervention of SelK SH3 binding domain can inhibit the vesicle formation and CD36 subcellular trafficking, significantly ameliorates NAFLD in mice. Collectively, our findings disclose an unexpected role of SelK in regulating NAFLD development, suggesting that targeting the SelK of hepatocytes may be a new therapeutic strategy for the treatment of NAFLD.

HIF-2α-induced upregulation of CD36 promotes the development of ccRCC.

Clear cell renal cell carcinoma (ccRCC) is characterized by the abundance of lipid droplets and the activation of the hypoxia-inducible factor (HIF) signaling pathway. However, the lipid reprogramming induced by HIF signaling in ccRCC is not fully understood. In this study, we found that the fatty acid receptor CD36 was highly expressed in human ccRCC tissues and ccRCC cell lines. CD36 overexpression increased fatty acid uptake and lipid droplet formation, and enhanced the proliferation and migration of ccRCC cells in a DGAT1-dependent manner. In contrast, the disruption of endogenous CD36 showed the opposite effects. The upregulated expression of CD36 in ccRCC was associated with hypoxia and HIF-2α activation. Furthermore, we identified CD36 as a new target of the transcription factor HIF-2α. The knockdown of CD36 in ccRCC cells reduced lipid accumulation and also blocked the tumor-promoting effects induced by HIF-2α under hypoxia. Our findings suggest that hypoxia-dependent HIF-2α promotes the remodeling of lipid metabolism and the malignant phenotype of ccRCC via CD36, providing a certain theoretical basis for clarifying the mechanism of ccRCC.

CD36-mediated metabolic crosstalk between tumor cells and macrophages affects liver metastasis.

Liver metastasis is highly aggressive and treatment-refractory, partly due to macrophage-mediated immune suppression. Understanding the mechanisms leading to functional reprogramming of macrophages in the tumor microenvironment (TME) will benefit cancer immunotherapy. Herein, we find that the scavenger receptor CD36 is upregulated in metastasis-associated macrophages (MAMs) and deletion of CD36 in MAMs attenuates liver metastasis in mice. MAMs contain more lipid droplets and have the unique capability in engulfing tumor cell-derived long-chain fatty acids, which are carried by extracellular vesicles. The lipid-enriched vesicles are preferentially partitioned into macrophages via CD36, that fuel macrophages and trigger their tumor-promoting activities. In patients with liver metastases, high expression of CD36 correlates with protumoral M2-type MAMs infiltration, creating a highly immunosuppressive TME. Collectively, our findings uncover a mechanism by which tumor cells metabolically interact with macrophages in TME, and suggest a therapeutic potential of targeting CD36 as immunotherapy for liver metastasis.