The fatty acid receptor CD36 promotes macrophage infiltration via p110γ signaling to stimulate metastasis.

INTRODUCTION: Metabolic regulators are key in controlling immune cell fate in the tumor microenvironment. The accumulation of tumor-associated macrophages (TAMs) in cancer greatly contributes to metastasis and poor outcome. However, the metabolic pathways responsible for TAM accumulation are largely unknown. OBJECTIVE: This study aims to elucidate the role of the fatty acid translocase CD36 in the regulation of TAM accumulation. METHODS: The immune profile was analyzed in patients with liver metastasis by CIBERSORT. Immunohistostaining of CD68 and CD36 was conducted in clinical specimens from patients with liver metastasis. Myeloid-specific CD36 knockout mice and their littermates were used to establish preclinical liver metastasis models. Subsequently, a series of experiments were used to explore the underlying mechanisms of how CD36 regulates TAM population. RESULTS: We found that massive TAM accumulation in patients with liver metastasis is associated with an upregulation of CD36 on TAMs. Liver metastasis is abundantly infiltrated by TAMs that are derived from circulating monocytes, but not tissue-resident macrophages. Myeloid-specific CD36 knockout specifically reduced and inactivated monocyte-differentiated macrophages, resulting in diminished immune suppression and attenuated liver metastasis. The protect effects of CD36 knockout can be abrogated by blockade of macrophage recruitment through CCR2 or the p110γ isoform of PI3K downstream of it. Mechanically, CD36 reprogrammed the lipid metabolism of macrophages, in which sphingolipids were significantly downregulated, that contributed to weakened lipid raft-dependent activation of p110γ. CONCLUSION: CD36 expands TAM population by promoting the recruitment of circulating monocytes through CCL2/CCR2/p110γ signaling. Our findings provide evidence for targeting CD36 as a therapeutic strategy against liver metastasis.

Aberrant serum-derived FN1 variants bind to integrin ß1 on glomerular endothelial cells contributing to thin basement membrane nephropathy.

The glomerular basement membrane (GBM) is a critical component of the glomerular filtration barrier (GFB), with its thickness directly influencing renal function. While a uniformly thinned GBM can cause hematuria while preserving normal renal function, this condition is typically diagnosed as thin basement membrane nephropathy (TBMN). However, the pathogenesis and potential progression to renal insufficiency of TBMN are not fully understood. In this study, we analyzed clinical cohorts presenting with microscopic hematuria who underwent genetic testing and identified five novel pathogenic FN1 mutations. Through bioinformatics analysis of these variants, expression localization analysis of GBM-related molecules in renal biopsies, and functional studies of the mutants, we found that these variants exhibited gain-of-function characteristics. This led to the excessive deposition of aberrant serum-derived FN1 variants on glomerular endothelial cells rather than cell-type-specific variants. The deposition competitively binds FN1 variants to Integrin ß1, disrupting the interaction with Laminin α5ß2γ1 and subsequently reducing the expression of key GBM components, resulting in TBMN. This study elucidated, for the first time, the genetic pathogenesis of TBMN caused by FN1 variants. It provides a crucial foundation for understanding the progression of renal dysfunction associated with simple hematuria, highlights the potential for targeted therapeutic strategies, and differentiates TBMN from early-stage Alport syndrome.

Tislelizumab versus Sorafenib in First-Line Treatment of Unresectable Hepatocellular Carcinoma: Impact on Health-Related Quality of Life in RATIONALE-301 Study.

Introduction: RATIONALE-301 (NCT03412773) was a global, phase 3 study comparing the efficacy and safety of tislelizumab with sorafenib as first-line (1L) treatment in adult patients with unresectable hepatocellular carcinoma (HCC) that met its primary endpoint of noninferiority in overall survival (OS). This analysis compared health-related quality-of-life (HRQOL) outcomes between the arms. Methods: Systemic therapy-naive adults with HCC were randomized 1:1 to receive tislelizumab (n = 342) or sorafenib (n = 332). HRQOL was assessed using EORTC QLQ-C30, QLQ-HCC18, and EQ-5D-5L. At cycles 4 and 6, a mixed model for repeated measures was performed using key-prespecified patient-reported outcome (PRO) endpoints of the QLQ-C30 and the QLQ-HCC18. Time to deterioration was analyzed with the Kaplan-Meier method using the PRO endpoints. Results: At cycles 4 and 6, patients in the tislelizumab arm had better HRQOL outcomes than the patients in the sorafenib arm per mean-change difference in GHS/QOL, QLQ-C30 physical functioning and fatigue, and QLQ-HCC18 symptom index; however, no differences for pain were observed. Patients in the tislelizumab arm had lower risk of deterioration in GHS/QOL (HR: 0.68; 95% CI: 0.49-0.94), QLQ-C30 physical functioning (HR: 0.45; 95% CI: 0.32-0.63) and fatigue (HR: 0.47; 95% CI: 0.36-0.61), QLQ-HCC18 symptom index (HR: 0.52; 95% CI: 0.34-0.81), and HCC-specific fatigue (HR: 0.59; 95% CI: 0.45-0.79). For pain, both arms had similar risk of deterioration (HR: 0.78; 95% CI: 0.56-1.09). At cycles 4 and 6, patients in the tislelizumab arm maintained in EQ-5D-5L visual analog scale, whereas scores decreased for the patients in the sorafenib arm. Conclusion: Patients with 1L HCC treated with tislelizumab had favorable HRQOL outcomes compared with patients treated with sorafenib, particularly in fatigue and physical functioning. These results, along with favorable safety profile, better response rate, and OS noninferiority, support tislelizumab as a potential 1L treatment option for unresectable HCC.

A high cholesterol diet aggravates experimental colitis through SREBP2-modulated endocytosis and degradation of occludin and Zo-1 proteins.

Disrupted cholesterol homeostasis plays a critical role in the development of multiple diseases, such as cardiovascular disease and cancer. However, the role of cholesterol in inflammatory bowel disease (IBD) remains unclear. In the present study, we investigated whether and how high levels of cholesterol in the diet affect experimental colitis in mice. A normal diet supplemented with 1.25% cholesterol (high cholesterol diet) caused more severe colitis and aggravated the disruption of intestinal tight junction structure, accompanied by higher colonic tissue total cholesterol (TC) levels in a dextran sulfate sodium (DSS)-induced experimental colitis mouse model. Cholesterol aggravated DSS-induced intestinal epithelial barrier impairment and nuclear sterol regulatory element-binding protein 2 (nSREBP2) inhibition both in vivo and in vitro. In addition, nSREBP2 overexpression ameliorated cholesterol-induced intestinal epithelial barrier disruption in Caco2 cells. Interestingly, inhibition of SREBP2 disrupted intestinal epithelial barrier in the absence of cholesterol. Furthermore, SREBP2 regulated the protein expression of tight junction proteins (occludin/Zo-1) via modulating caveolin-1-mediated endocytosis and lysosomal degradation. Analysis of UK Biobank data indicated that, in fully adjusted models, higher serum TC concentrations were an independent protective factor for IBD incidence. The sterol regulatory element-binding factor 2 (SREBF2) gene rs2228313 (G/C) genetic variant was associated with the incidence of IBD and the CC genotype of SREBF2 rs2228313 was associated with higher serum TC levels and decreased the risk of IBD. In summary, a high cholesterol diet aggravates DSS-induced colitis in mice by down-regulating nSREBP2 expression, thereby promoting the endocytic degradation of tight junction proteins. In humans, SREBF2 gene single nucleotide polymorphism rs2228313 and serum TC levels are associated with IBD incidence.

Amphiphilic disodium glycyrrhizin as a co-former for ketoconazole co-amorphous systems: Biopharmaceutical properties and underlying molecular mechanisms.

Co-amorphous systems (CAMs) have been extensively investigated to improve the dissolution of hydrophobic drugs. However, drug precipitation during the storage or dissolution of CAMs has still been a major challenge. Here, disodium glycyrrhizin (Na2GA) was first used as a co-former in CAMs based on its multiple hydroxyl groups and amphiphilic structure. Ketoconazole (KTZ), a BCS class II drug, was selected as a model drug. KTZ-Na2GA CAMs at mass ratios of 1:1, 1:2.5, 1:5 and 1:10 were prepared by the spray drying method and further characterised by PXRD and DSC. The 1:2.5, 1:5 and 1:10 groups exhibited significantly enhanced Cmax (all approximately 26.67-fold) and stable maintenance of supersaturation compared to the crystalline KTZ and the corresponding physical mixtures in non-sink dissolution tests, while the 1:1 group exhibited an unstable medium Cmax (all approximately 14.67-fold). The permeability tests revealed that the permeation rate of KTZ in KTZ-Na2GA CAMs under the concentration of Na2GA in solution above the critical micelle concentration (CMC) showed a significant downwards trend compared to that below CMC. The underlying molecular mechanisms were involved in molecular miscibility, hydrogen bond interactions, solubilisation and crystallisation inhibition by Na2GA. Pharmacokinetic studies demonstrated that the AUC0-∞ of KTZ in 1:1, 1:2.5, 1:5 and 1:10 groups were significantly higher than those of the crystalline KTZ group with 2.13-, 2.30-, 2.16- and 1.86-fold, respectively (p < 0.01). In conclusion, Na2GA has proven to be a promising co-former in CAMs to enhance hydrophobic drug dissolution and bioavailability. Its effect on intestinal permeation rate of drugs also deserves attention.

Characterization of a monkey model with experimental retinal damage induced by N-methyl-D-aspartate.

N-methyl-D-aspartate (NMDA)-induced retinal damage has been well studied in rodents, but the detailed mechanisms have not yet been characterized in nonhuman primates. Here, we characterized the retinal degenerative effects of NMDA on rhesus monkeys in vivo. NMDA saline or saline-only control was injected intravitreally to the randomly assigned eyes and contralateral eyes of four rhesus monkeys, respectively. The structural and functional changes of retina were characterized by optical coherence tomography and electroretinography on days 0, 4, 30 and 60 post injection. Both optic discs and macular areas of the NMDA-injected eyes initially presented with a transient retinal thickening, followed by continued retinal thinning. The initial, transient retinal thickening has also been observed in glaucoma patients, but this has not been reported in rodent NMDA models. This initial response was followed by loss of retina ganglion cells (RGCs), which is similar to glaucomatous optic neuropathy and other RGC-related retinal degenerations. The amplitudes of both the photopic negative response and pattern electroretinogram decreased significantly and remained low until the end of the study. Thus, the NMDA monkey model may serve as a more clinically relevant animal model of retinal damage.

CT-based deep learning radiomics biomarker for programmed cell death ligand 1 expression in non-small cell lung cancer.

BACKGROUND: Programmed cell death ligand 1 (PD-L1), as a reliable predictive biomarker, plays an important role in guiding immunotherapy of lung cancer. To investigate the value of CT-based deep learning radiomics signature to predict PD-L1 expression in non-small cell lung cancers(NSCLCs). METHODS: 259 consecutive patients with pathological confirmed NSCLCs were retrospectively collected and divided into the training cohort and validation cohort according to the chronological order. The univariate and multivariate analyses were used to build the clinical model. Radiomics and deep learning features were extracted from preoperative non-contrast CT images. After feature selection, Radiomics score (Rad-score) and deep learning radiomics score (DLR-score) were calculated through a linear combination of the selected features and their coefficients. Predictive performance for PD-L1 expression was evaluated via the area under the curve (AUC) of receiver operating characteristic, the calibration curves, and the decision curve analysis. RESULTS: The clinical model based on Cytokeratin 19 fragment and lobulated shape obtained an AUC of 0.767(95% CI: 0.673-0.860) in the training cohort and 0.604 (95% CI:0.477-0.731) in the validation cohort. 11 radiomics features and 15 deep learning features were selected by LASSO regression. AUCs of the Rad-score were 0.849 (95%CI: 0.783-0.914) and 0.717 (95%CI: 0.607-0.826) in the training cohort and validation cohort, respectively. AUCs of DLR-score were 0.938 (95%CI: 0.899-0.977) and 0.818(95%CI:0.727-0.910) in the training cohort and validation cohort, respectively. AUCs of the DLR-score were significantly higher than those of the Rad-score and the clinical model. CONCLUSION: The CT-based deep learning radiomics signature could achieve clinically acceptable predictive performance for PD-L1 expression, which showed potential to be a surrogate imaging biomarker or a complement of immunohistochemistry assessment.

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.

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.

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.

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.

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.