Natural Pyrethrin-Induced Oxidative Damage in Human Liver Cells through Nrf-2 Signaling Pathway.

Natural pyrethrins (NPs), one kind of bio-pesticide, have been widely used in organic agriculture and ecological environment studies. Studies have shown that NPs may affect the metabolism of rat liver and human hepatocytes; nevertheless, the toxic effects of NPs on the liver and the related mechanisms are still incompletely understood. In this research, we utilized three types of human liver cells to investigate the mechanism of NPs' induction of oxidative stress. The results showed that NPs exhibit noteworthy cytotoxic effects on human liver cells. These effects are characterized by the induction of LDH release, mitochondrial collapse, and an increased production of ROS and MDA content, subsequently activating the Kelch-like ECH-associated protein 1/Nuclear factor erythroid 2- related factor 2 (Keap1/Nrf-2) pathway. The ROS inhibitor N-acetyl-L-cysteine (NAC) can alleviate ROS/Nrf2-mediated oxidative stress. In addition, the siRNA knockdown of Nrf-2 exacerbated the injury, including ROS production, and inhibited cell viability. In summary, the ROS-mediated Keap1/Nrf-2 pathway could be an important regulator of NP-induced damage in human liver cells, which further illustrates the hepatotoxicity of NPs and thereby contributes to the scientific basis for further exploration.

Plasminogen degrades α-synuclein, Tau and TDP-43 and decreases dopaminergic neurodegeneration in mouse models of Parkinson's disease.

Parkinson's disease (PD) is the second most frequently diagnosed neurodegenerative disease, and it is characterized by the intracellular and extracellular accumulation of α-synuclein (α-syn) and Tau, which are major components of cytosolic protein inclusions called Lewy bodies, in the brain. Currently, there is a lack of effective methods that preventing PD progression. It has been suggested that the plasminogen activation system, which is a major extracellular proteolysis system, is involved in PD pathogenesis. We investigated the functional roles of plasminogen in vitro in an okadaic acid-induced Tau hyperphosphorylation NSC34 cell model, ex vivo using brains from normal controls and methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, and in vivo in a widely used MPTP-induced PD mouse model and an α-syn overexpression mouse model. The in vitro, ex vivo and in vivo results showed that the administered plasminogen crossed the blood‒brain barrier (BBB), entered cells, and migrated to the nucleus, increased plasmin activity intracellularly, bound to α-syn through lysine binding sites, significantly promoted α-syn, Tau and TDP-43 clearance intracellularly and even intranuclearly in the brain, decreased dopaminergic neurodegeneration and increased the tyrosine hydroxylase levels in the substantia nigra and striatum, and improved motor function in PD mouse models. These findings indicate that plasminogen plays a wide range of pivotal protective roles in PD and therefore may be a promising drug candidate for PD treatment.

Genetically determined metabolites in allergic conjunctivitis: A Mendelian randomization study.

Background: Allergic conjunctivitis (AC) afflicts a significant portion of the global populace. Yet, its metabolic foundations remain largely unexplored. Methods: We applied Mendelian Randomization (MR) and Linkage Disequilibrium Score Regression (LDSC) to scrutinize a cohort comprising 20 958 AC cases and 356 319 controls. Data were amalgamated from the metabolomics GWAS server and the FinnGen project, under strict quality control protocols. Results: Using two-sample MR analysis, 486 blood metabolites were investigated in relation to AC. The IVW approach highlighted 18 metabolites as closely tied to AC risk; of these, 16 retained significance post sensitivity assessments for heterogeneity and horizontal pleiotropy. LDSC analysis, adopted to bolster our findings and negate confounders from shared genetic markers, revealed 8 metabolites with marked heritability, including: palmitate (OR = 0.614), 3-methoxytyrosine (OR = 0.657), carnitine (OR = 1.368), threonate (OR = 0.828), N-[3-(2-Oxopyrrolidin-1-yl)propyl]acetamide (OR = 1.257), metoprolol acid metabolite (OR = 0.982), oleoylcarnitine (OR = 0.635), and 2-palmitoylglycerophosphocholine (OR = 1.351). Conclusion: AC is precipitated by ocular responses to environmental allergens. Our study unveils a causal link between 8 blood metabolites and AC. This insight accentuates the role of metabolites in AC onset, suggesting novel avenues for its early prediction, targeted prevention, and tailored therapeutic interventions.

Associations between Geriatric Nutrition Risk Index, bone mineral density and body composition in type 2 diabetes patients.

BACKGROUND: Type 2 diabetes mellitus (T2DM), a fast-growing issue in public health, is one of the most common chronic metabolic disorders in older individuals. Osteoporosis and sarcopenia are highly prevalent in T2DM patients and may result in fractures and disabilities. In people with T2DM, the association between nutrition, sarcopenia, and osteoporosis has rarely been explored. AIM: To evaluate the connections among nutrition, bone mineral density (BMD) and body composition in patients with T2DM. METHODS: We enrolled 689 patients with T2DM for this cross-sectional study. All patients underwent dual energy X-ray absorptiometry (DXA) examination and were categorized according to baseline Geriatric Nutritional Risk Index (GNRI) values calculated from serum albumin levels and body weight. The GNRI was used to evaluate nutritional status, and DXA was used to investigate BMD and body composition. Multivariate forward linear regression analysis was used to identify the factors associated with BMD and skeletal muscle mass index. RESULTS: Of the total patients, 394 were men and 295 were women. Compared with patients in tertile 1, those in tertile 3 who had a high GNRI tended to be younger and had lower HbA1c, higher BMD at all bone sites, and higher appendicular skeletal muscle index (ASMI). These important trends persisted even when the patients were divided into younger and older subgroups. The GNRI was positively related to ASMI (men: r = 0.644, P < 0.001; women: r = 0.649, P < 0.001), total body fat (men: r = 0.453, P < 0.001; women: r = 0.557, P < 0.001), BMD at all bone sites, lumbar spine (L1-L4) BMD (men: r = 0.110, P = 0.029; women: r = 0.256, P < 0.001), FN-BMD (men: r = 0.293, P < 0.001; women: r = 0.273, P < 0.001), and hip BMD (men: r = 0.358, P < 0.001; women: r = 0.377, P < 0.001). After adjustment for other clinical parameters, the GNRI was still significantly associated with BMD at the lumbar spine and femoral neck. Additionally, a low lean mass index and higher ß-collagen special sequence were associated with low BMD at all bone sites. Age was negatively correlated with ASMI, whereas weight was positively correlated with ASMI. CONCLUSION: Poor nutrition, as indicated by a low GNRI, was associated with low levels of ASMI and BMD at all bone sites in T2DM patients. Using the GNRI to evaluate nutritional status and using DXA to investigate body composition in patients with T2DM is of value in assessing bone health and physical performance.

Ultrathin and Biodegradable Bismuth Oxycarbonate Nanosheets with Massive Oxygen Vacancies for Highly Efficient Tumor Therapy.

Nanomaterials doped with high atom number elements can improve the efficacy of cancer radiotherapy, but their clinical application faces obstacles, such as being difficult to degrade in vivo, or still requiring relatively high radiation dose. In this work, a bismuth oxycarbonate-based ultrathin nanosheet with the thickness of 2.8 nm for safe and efficient tumor radiotherapy under low dose of X-ray irradiation is proposed. The high oxygen content (62.5% at%) and selective exposure of the facets of ultrathin 2D nanostrusctures facilitate the escape of large amounts of oxygen atoms on bismuth nanosheets from surface, forming massive oxygen vacancies and generating reactive oxygen species that explode under the action of X-rays. Moreover, the exposure of almost all atoms to environmental factors and the nature of oxycarbonates makes the nanosheets easily degrade into biocompatible species. In vivo studies demonstrate that nanosheets could induce apoptosis in cancer cells after low dose of X-ray irradiation without causing any damage to the liver or kidney. The tumor growth inhibition effect of radiotherapy increases from 49.88% to 90.76% with the help of bismuth oxycarbonate nanosheets. This work offers a promising future for nanosheet-based clinical radiotherapies of malignant cancers.

Development of Polymethine Dyes for NIR-II Fluorescence Imaging and Therapy.

Fluorescence imaging in the second near-infrared window (NIR-II) is burgeoning because of its higher imaging fidelity in monitoring physiological and pathological processes than clinical visible/the second near-infrared window fluorescence imaging. Notably, the imaging fidelity is heavily dependent on fluorescence agents. So far, indocyanine green, one of the polymethine dyes, with good biocompatibility and renal clearance is the only dye approved by the Food and Drug Administration, but it shows relatively low NIR-II brightness. Importantly, tremendous efforts are devoted to synthesizing polymethine dyes for imaging preclinically and clinically. They have shown feasibility in the customization of structure and properties to fulfill various needs in imaging and therapy. Herein, a timely update on NIR-II polymethine dyes, with a special focus on molecular design strategies for fluorescent, photoacoustic, and multimodal imaging, is offered. Furthermore, the progress of polymethine dyes in sensing pathological biomarkers and even reporting drug release is illustrated. Moreover, the NIR-II fluorescence imaging-guided therapies with polymethine dyes are summarized regarding chemo-, photothermal, photodynamic, and multimodal approaches. In addition, artificial intelligence is pointed out for its potential to expedite dye development. This comprehensive review will inspire interest among a wide audience and offer a handbook for people with an interest in NIR-II polymethine dyes.

Identification of G-quadruplex-interacting proteins in living cells using an artificial G4-targeting biotin ligase.

G-quadruplexes (G4s) are noncanonical nucleic acid structures pivotal to cellular processes and disease pathways. Deciphering G4-interacting proteins is imperative for unraveling G4's biological significance. In this study, we developed a G4-targeting biotin ligase named G4PID, meticulously assessing its binding affinity and specificity both in vitro and in vivo. Capitalizing on G4PID, we devised a tailored approach termed G-quadruplex-interacting proteins specific biotin-ligation procedure (PLGPB) to precisely profile G4-interacting proteins. Implementing this innovative strategy in live cells, we unveiled a cohort of 149 potential G4-interacting proteins, which exhibiting multifaceted functionalities. We then substantiate the directly binding affinity of 7 candidate G4-interacting-proteins (SF3B4, FBL, PP1G, BCL7C, NDUV1, ILF3, GAR1) in vitro. Remarkably, we verified that splicing factor 3B subunit 4 (SF3B4) binds preferentially to the G4-rich 3' splice site and the corresponding splicing sites are modulated by the G4 stabilizer PDS, indicating the regulating role of G4s in mRNA splicing procedure. The PLGPB strategy could biotinylate multiple proteins simultaneously, which providing an opportunity to map G4-interacting proteins network in living cells.

Edaravone dexborneol protects against cerebral ischemia/reperfusion-induced blood-brain barrier damage by inhibiting ferroptosis via activation of nrf-2/HO-1/GPX4 signaling.

PURPOSE: Ferroptosis has recently been recognized as a mechanism of cerebral ischemia-reperfusion (I/R) injury, attributed to blood-brain barrier (BBB) disruption. Edaravone dexboneol (Eda.B) is a novel neuroprotective agent widely employed in ischemic stroke, which is composed of edaravone (Eda) and dexborneol. This study aimed to investigate the protective effects of Eda.B on the BBB in cerebral I/R and explore its potential mechanisms. METHODS: Transient middle cerebral artery occlusion (tMCAO) Sprague-Dawley-rats model was used. Rats were randomly assigned to sham-operated group (sham, n = 20), model group (tMCAO, n = 20), Eda.B group (Eda.B, n = 20), Eda group (Eda, n = 20) and dexborneol group (dexborneol, n = 20), and Eda.B + Zinc protoporphyria group (Eda.B + ZnPP, n = 5). Infarct area, cellular apoptosis and neurofunctional recovery were accessed through TTC staining, TUNEL staining, and modified Garcia scoring system, respectively. BBB integrity was evaluated via Evans blue staining. Nuclear factor E2 related factor 2 (Nrf-2)/heme oxygenase 1 (HO-1)/glutathione peroxidase 4 (GPX4) signaling were qualified by Western blot. Transmission electron microscopy (TEM) revealed alterations in ipsilateral brain tissue among groups. Glutathione (GSH) and malondialdehyde (MDA) levels, and Fe2+ tissue content determination were detected. RESULTS: Eda.B effectively improved neurological deficits, diminished infarct area and cellular apoptosis, as well as ameliorated BBB integrity in tMCAO rats. Further, Eda.B significantly inhibited ferroptosis, as evidenced by ameliorated pathological features of mitochondria, down-regulated of MDA and Fe2+ levels and up-regulated GSH content. Mechanistically, Eda.B attenuated BBB disruption via Nrf-2-mediated ferroptosis, promoting nuclear translocation of Nrf-2, increasing HO-1, GPX4 expression, alleviating the loss of zonula occludens 1 (ZO-1) and occludin as well as decreasing 4-hydroxynonenal (4-HNE) level. CONCLUSIONS: This study revealed for the first time that Eda.B safeguarded the BBB from cerebral I/R injury by inhibiting ferroptosis through the activation of the Nrf-2/HO-1/GPX4 axis, providing a novel insight into the neuroprotective effect of Eda.B in cerebral I/R.

Promoting the healing of diabetic wounds with an antimicrobial gel containing AgNPs with anti-infective and anti-inflammatory properties.

Diabetic wounds are prone to develop chronic wounds due to bacterial infection and persistent inflammatory response. However, traditional dressings are monofunctional, lack bioactive substances, have limited bacterial inhibition as well as difficulties in adhesion and retention. These limit the therapeutic efficacy of traditional dressings on diabetic wounds. Therefore, finding and developing efficient and safe wound dressings is currently an urgent clinical need. In this study, an antimicrobial gel loaded with silver nanoparticles (AgNPs) (referred to as AgNPs@QAC-CBM) was prepared by crosslinking quaternary ammonium chitosan (QAC) with carbomer (CBM) as a gel matrix. AgNPs@QAC-CBM exhibited a reticulated structure, strong adhesion, good stability, and remarkable bactericidal properties, killing 99.9% of Escherichia coli, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa within 1 min. Furthermore, AgNPs@QAC-CBM improved the wound microenvironment and accelerated wound healing in diabetic mice by promoting tissue production and collagen deposition, inducing M2 macrophages, reducing pro-inflammatory factor secretion and increasing anti-inflammatory factor levels. Moreover, AgNPs@QAC-CBM was proven to be safe for use through skin irritation and cytotoxicity tests, as they did not cause any irritation or toxicity. To summarize, AgNPs@QAC-CBM showed promising potential in enhancing the diabetic wound healing process.

A late eating midpoint is associated with increased risk of diabetic kidney disease: a cross-sectional study based on NHANES 2013-2020.

BACKGROUND: Modifying diet is crucial for diabetes and complication management. Numerous studies have shown that adjusting eating habits to align with the circadian rhythm may positively affect metabolic health. However, eating midpoint, eating duration, and their associations with diabetic kidney disease (DKD) are poorly understood. METHODS: The National Health and Nutrition Examination Survey (2013-2020) was examined for information on diabetes and dietary habits. From the beginning and ending times of each meal, we calculated the eating midpoint and eating duration. Urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g and/or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 were the specific diagnostic criteria for DKD. RESULTS: In total, details of 2194 subjects with diabetes were collected for analysis. The overall population were divided into four subgroups based on the eating midpoint quartiles. The prevalence of DKD varied noticeably (P = 0.037) across the four categories. When comparing subjects in the second and fourth quartiles of eating midpoint to those in the first one, the odds ratios (ORs) of DKD were 1.31 (95% CI, 1.03 to 1.67) and 1.33 (95% CI, 1.05 to 1.70), respectively. And after controlling for potential confounders, the corresponding ORs of DKD in the second and fourth quartiles were 1.42 (95% CI, 1.07 to 1.90) and 1.39 (95% CI, 1.04 to 1.85), respectively. CONCLUSIONS: A strong correlation was found between an earlier eating midpoint and a reduced incidence of DKD. Eating early in the day may potentially improve renal outcomes in patients with diabetes.

Effect of Infusion Set Replacement Intervals on Central Line-Associated Bloodstream Infection in the Intensive Care Unit: Study Protocol of the INSPIRATION Study.

INTRODUCTION: The replacement intervals for infusion sets may differ among healthcare institutions, which may have an impact on the occurrence of central line-associated bloodstream infections (CLABSI). Nevertheless, there exists a limited amount of high-quality evidence available to assist clinicians in determining the most suitable replacement intervals for infusion sets. Therefore, the objective of this trial is to compare the efficacy of 24-h and 96-h replacement intervals for infusion sets on CLABSI among critically ill adults who have central venous access devices. METHODS: This is a multicenter, parallel-group randomized controlled trial that will investigate the effect of infusion set replacement intervals on CLABSI in adult patients admitted to intensive care units (ICUs). The study will enroll 1240 participants who meet the inclusion criteria, which includes being 18 years or older, expected to stay in the ICU for longer than 96 h, and in need of central venous access. Participants will be randomly assigned to either a control group receiving a 96-h replacement interval or a treatment group receiving a 24-h replacement interval. PLANNED OUTCOME: The primary outcome of this trial is the rate of CLABSI within 28 days after randomization. CONCLUSION: This is the first randomized controlled trial to investigate the effects of infusion set replacement at 24-h and 96-h intervals on CLABSI in ICU patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT05359601.

Hyaluronan degradation by HYAL2 is essential for odontoblastic differentiation and migration of mouse dental papilla cells.

The coordination between odontoblastic differentiation and directed cell migration of mesenchymal progenitors is necessary for regular dentin formation. The synthesis and degradation of hyaluronan (HA) in the extracellular matrix create a permissive niche that directly regulates cell behaviors. However, the role and mechanisms of HA degradation in dentin formation remain unknown. In this work, we present that HA digestion promotes odontoblastic differentiation and cell migration of mouse dental papilla cells (mDPCs). Hyaluronidase 2 (HYAL2) is responsible for promoting odontoblastic differentiation through degrading HA, while hyaluronidase 1 (HYAL1) exhibits negligible effect. Silencing Hyal2 generates an extracellular environment rich in HA, which attenuates F-actin and filopodium formation and in turn inhibits cell migration of mDPCs. In addition, activating PI3K/Akt signaling significantly rescues the effects of HA accumulation on cytodifferentiation. Taken together, the results confirm the contribution of HYAL2 to HA degradation in dentinogenesis and uncover the mechanism of the HYAL2-mediated HA degradation in regulating the odontoblastic differentiation and migration of mDPCs.

Clinical Efficacy and Long-term Prognosis of High Flux Hemodialysis Combined with Different Frequency Hemodiafiltration in the Treatment of Middle-Aged and Elderly Patients with Uremia.

INTRODUCTION: To analyze the clinical efficacy and long-term prognosis of high flux hemodialysis (HFHD) combined with different frequency hemodiafiltration (HDF) in uremic patients. METHODS: 86 middle-aged and elderly patients with uremia were divided into the HF group (HFHD combined with high-frequency HDF) and the LF group (HFHD combined with low-frequency HDF). The changes between the two groups in various indicators after 12 months of dialysis and the survival rate at 5 years of follow-up were compared. We used SPSS 25.0 software for data analysis. RESULTS: The differences of the levels of serum albumin, hemoglobin and transferrin in HF Group was significantly higher than LF Group before and after treatment (P < .05). The differences of the levels and clearance rate of calcium, phosphorus, parathyroid hormone, ß2-microglobulin and cysteine protease inhibitor C in the patients' blood after dialysis were significantly higher in HF Group than in LF Group (P < .05). The all-cause mortality rate, new cardiovascular event rate, new cerebrovascular event rate, and new infection event rate of HF Group were significantly lower than those of LFHD group, respectively (P < .05). The LF Group had a significantly higher risk of all-cause mortality events, new cardiovascular cerebrovascular and infectious events than the HF Group (P < .05). CONCLUSION: 1 week/time HDF combined with HFHD can more effectively eliminate the vascular related toxins in middle-aged and elderly patients with uremia, improve their nutritional status, treatment effect, and long-term prognosis.  DOI: 10.52547/ijkd.7864.

Lactate modulates RNA splicing to promote CTLA-4 expression in tumor-infiltrating regulatory T cells.

RNA splicing is involved in cancer initiation and progression, but how it influences host antitumor immunity in the metabolically abnormal tumor microenvironment (TME) remains unclear. Here, we demonstrate that lactate modulates Foxp3-dependent RNA splicing to maintain the phenotypic and functional status of tumor-infiltrating regulatory T (Treg) cells via CTLA-4. RNA splicing in Treg cells was correlated with the Treg cell signatures in the TME. Ubiquitin-specific peptidase 39 (USP39), a component of the RNA splicing machinery, maintained RNA-splicing-mediated CTLA-4 expression to control Treg cell function. Mechanistically, lactate promoted USP39-mediated RNA splicing to facilitate CTLA-4 expression in a Foxp3-dependent manner. Moreover, the efficiency of CTLA-4 RNA splicing was increased in tumor-infiltrating Treg cells from patients with colorectal cancer. These findings highlight the immunological relevance of RNA splicing in Treg cells and provide important insights into the environmental mechanism governing CTLA-4 expression in Treg cells.

Compromised very-low density lipoprotein induced polyunsaturated triglyceride accumulation in N-nitrosodiethylamine-induced hepatic steatosis.

N-Nitrosodiethylamine (NDEA), a carcinogen in some foods and medications, is linked to liver damage similar to non-alcoholic fatty liver disease (NAFLD). This study explores how NDEA disrupts liver lipid metabolism. Sprague-Dawley rats were given two doses of NDEA (100 mg/kg) orally, 24 h apart. Liver response was assessed through tissue staining, blood tests, and biochemical markers, including fatty acids, lipid peroxidation, and serum very-low density lipoprotein (VLDL) levels. Additionally, lipidomic analysis of liver tissues and serum was performed. The results indicated significant hepatic steatosis (fat accumulation in the liver) following NDEA exposure. Blood analysis showed signs of inflammation and liver damage. Biochemical tests revealed decreased liver protein synthesis and specific enzyme alterations, suggesting liver cell injury but maintaining mitochondrial function. Increased fatty acid levels without a rise in lipid peroxidation were observed, indicating fat accumulation. Lipidomic analysis showed increased polyunsaturated triglycerides in the liver and decreased serum VLDL, implicating impaired VLDL transport in liver dysfunction. In conclusion, NDEA exposure disrupts liver lipid metabolism, primarily through the accumulation of polyunsaturated triglycerides and impaired fat transport. These findings provide insight into the mechanisms of NDEA-induced liver injury and its progression to hepatic steatosis.

ZNF143 deletion alters enhancer/promoter looping and CTCF/cohesin geometry.

The transcription factor ZNF143 contains a central domain of seven zinc fingers in a tandem array and is involved in 3D genome construction. However, the mechanism by which ZNF143 functions in chromatin looping remains unclear. Here, we show that ZNF143 directionally recognizes a diverse range of genomic sites directly within enhancers and promoters and is required for chromatin looping between these sites. In addition, ZNF143 is located between CTCF and cohesin at numerous CTCF sites, and ZNF143 removal narrows the space between CTCF and cohesin. Moreover, genetic deletion of ZNF143, in conjunction with acute CTCF degradation, reveals that ZNF143 and CTCF collaborate to regulate higher-order topological chromatin organization. Finally, CTCF depletion enlarges direct ZNF143 chromatin looping. Thus, ZNF143 is recruited by CTCF to the CTCF sites to regulate CTCF/cohesin configuration and TAD (topologically associating domain) formation, whereas directional recognition of genomic DNA motifs directly by ZNF143 itself regulates promoter activity via chromatin looping.

Interventing mitochondrial PD-L1 suppressed IFN-γ-induced cancer stemness in hepatocellular carcinoma by sensitizing sorafenib-induced ferroptosis.

Evidence recently showed that pleiotropic cytokine interferon-gamma (IFN-γ) in the tumor microenvironment (TME) plays a positive role in hepatocellular carcinoma (HCC) progression through the regulation of liver cancer stem cells (LCSCs) in HCC. The present study explored the role and potential mechanism of mitochondrial programmed cell death-ligand 1 (PD-L1) and its regulation of ferroptosis in modulating the cancer stemness of LCSCs. It was shown that mimicking TME IFN-γ exposure increased the LCSCs ratio and cancer stemness phenotypes in HCC cells. IFN-γ exposure inhibited sorafenib (Sora)-induced ferroptosis by enhancing glutathione peroxidase 4 (GPX4) expression as well reactive oxygen species (ROS) and lipid peroxidation (LPO) generation in LCSCs. Furthermore, IFN-γ exposure upregulated PD-L1 expression and its mitochondrial translocation, inducing dynamin-related protein 1 (Drp1)-dependent mitochondrial fission and correlating with glycolytic metabolism reprogramming in LCSCs. The genetic intervention of PD-L1 promoted ferroptosis-dependent anti-tumor effects of Sora, reduced glycolytic metabolism reprogramming, and inhibited cancer stemness of HCC in vitro and in vivo. Our results revealed a novel mechanism that IFN-γ exposure-induced mitochondrial translocation of PD-L1 enhanced glycolytic reprogramming to mediate the GPX4-dependent ferroptosis resistance and cancer stemness in LCSCs. This study provided new insights into the role of mitochondrial PD-L1-Drp1-GPX4 signal axis in regulating IFN-γ exposure-associated cancer stemness in LCSCs and verified that PD-L1-targeted intervention in combination with Sora might achieve promising synergistic anti-HCC effects.

Outward-oriented sites within clustered CTCF boundaries are key for intra-TAD chromatin interactions and gene regulation.

CTCF plays an important role in 3D genome organization by adjusting the strength of chromatin insulation at TAD boundaries, where clustered CBS (CTCF-binding site) elements are often arranged in a tandem array with a complex divergent or convergent orientation. Here, using Pcdh and HOXD loci as a paradigm, we look into the clustered CTCF TAD boundaries and find that, counterintuitively, outward-oriented CBS elements are crucial for inward enhancer-promoter interactions as well as for gene regulation. Specifically, by combinatorial deletions of a series of putative enhancer elements in mice in vivo or CBS elements in cultured cells in vitro, in conjunction with chromosome conformation capture and RNA-seq analyses, we show that deletions of outward-oriented CBS elements weaken the strength of long-distance intra-TAD promoter-enhancer interactions and enhancer activation of target genes. Our data highlight the crucial role of outward-oriented CBS elements within the clustered CTCF TAD boundaries in developmental gene regulation and have interesting implications on the organization principles of clustered CTCF sites within TAD boundaries.

De novo NAD+ synthesis contributes to CD8+ T cell metabolic fitness and antitumor function.

The dysfunction and clonal constriction of tumor-infiltrating CD8+ T cells are accompanied by alterations in cellular metabolism; however, how the cell-intrinsic metabolic pathway specifies intratumoral CD8+ T cell features remains elusive. Here, we show that cell-autonomous generation of nicotinamide adenine dinucleotide (NAD+) via the kynurenine pathway (KP) contributes to the maintenance of intratumoral CD8+ T cell metabolic and functional fitness. De novo NAD+ synthesis is involved in CD8+ T cell metabolism and antitumor function. KP-derived NAD+ promotes PTEN deacetylation, thereby facilitating PTEN degradation and preventing PTEN-dependent metabolic defects. Importantly, impaired cell-autonomous NAD+ synthesis limits CD8+ T cell responses in human colorectal cancer samples. Our results reveal that KP-derived NAD+ regulates the CD8+ T cell metabolic and functional state by restricting PTEN activity and suggest that modulation of de novo NAD+ synthesis could restore CD8+ T cell metabolic fitness and antitumor function.