Exchange Bias Induced by the Spin-Glass-Like State in a Te-Rich FeGeTe van der Waals Ferromagnet.

We have experimentally investigated the mechanism of the exchange bias in 2D van der Waals (vdW) ferromagnets by means of the anomalous Hall effect (AHE) together with the dynamical magnetization property. The temperature dependence of the AC susceptibility with its frequency response indicates a glassy transition of the magnetic property for the Te-rich FeGeTe vdW ferromagnet. We also found that the irreversible temperature dependence in the anomalous Hall voltage follows the de Almeida-Thouless line. Moreover, the freezing temperature of the spin-glass-like phase is found to correlate with the disappearance temperature of the exchange bias. These important signatures suggest that the emergence of magnetic exchange bias in the 2D van der Waals ferromagnets is induced by the presence of the spin-glass-like state in FeGeTe. The unprecedented insights gained from these findings shed light on the underlying principles governing exchange bias in vdW ferromagnets, contributing to the advancement of our understanding.

Heterogeneous ice nucleation of salt solution in porous media.

Water ubiquitously exists with dissolved salt in both natural and engineered porous media, such as soil, rock, concrete, and tissue; therefore, its freezing temperature depression behavior is of particular interest to various scientific communities tackling with mechanics and physics of porous media. To date, it remains elusive which physical mechanism accounts for its freezing temperature depression and how dissolved ions affect it. Herein, a series of pore-scale experiments were designated to investigate the freezing temperature of salt solutions in tubes with varying pore diameters, pore solution volumes, solid-liquid interfacial areas, ion concentrations, and ion types. The results reveal two main findings: (i) the freezing temperature depression of pore solutions is governed by the heterogeneous ice nucleation (HIN) at the water-solid interface, as evidenced by the observation that the freezing temperature decreases with the decreasing solid-liquid interfacial areas, regardless of pore diameter and pore solution volume; (ii) the dissolved salts alter HIN processes via changing the osmotic potential across the ice embryo-liquid water interface, as indicated by the observation that the freezing temperature is mainly determined by the salt concentration irrespective of salt types. Furthermore, the classical nucleation theory model is adapted for the freezing behavior of pore solutions by including an osmotic potential term. The model shows excellent performance in capturing experimental data with various pore solution concentrations, further substantiating the HIN as the physical mechanism governing pore solution freezing.

Synthesis and evaluation of novel fused pyrimidine derivatives as GPR119 agonists.

A novel series of fused pyrimidine derivatives were designed, synthesized and evaluated as GPR119 agonists. Among them, cyclohexene fused compounds (tetrahydroquinazolines) showed greater GPR119 agonistic activities than did dihydrocyclopentapyrimidine and tetrahydropyridopyrimidine scaffolds. Analogues (16, 19, 26, 28, 42) bearing endo-N-Boc-nortropane amine and fluoro-substituted aniline exhibited better EC50 values (0.27-1.2 µM) though they appeared to be partial agonists.

[Study on neoflavonoids from heartwood of Dalbergia latifolia].

Dalbergiae Odoriferae Lignum is derived from heartwood of Dalbergia odorifera,which is national Ⅱ level of rare and endangered protective plants in China. Its resources are scarce and its price is high. In order to find substitutes of D. odorifera,the chemical constituents of 70% ethanol extract of heartwood of D. catifolia were systematically studied by using silica gel,Sephadex LH-20 column chromatography,and semi-preparative HPLC. Sixteen neoflavanoids were isolated and identified as eight dalbergiphenols( 1-8),three dalbergiones( 9-11),two dalbergins( 12,13),two benzophenones( 14,15) and one other type neoflavanoids( 16) based on spectroscopic data analyses and/or comparing the spectroscopic data with those in literature. Among them,compounds 3,7 and 11 were isolated from the genus Dalbergia for the first time,and compounds 2,4-6,8,14 and 15 were isolated from the D. latifolia for the first time. Ten neoflavonoids were both discovered from D. latifolia and D. odorifera.

Efficient Thermo-Spin Conversion in van der Waals Ferromagnet FeGaTe.

Recent discovery of 2D van der Waals magnetic materials has spurred progress in developing advanced spintronic devices. A central challenge lies in enhancing the spin-conversion efficiency for building spin-logic or spin-memory devices. Here, the anomalous Hall and Nernst effects are systematically investigated to uncover significant spin-conversion effects in above-room-temperature van der Waals ferromagnet FeGaTe with perpendicular magnetic anisotropy. The anomalous Hall effect demonstrates an efficient electric spin-charge conversion with a notable spin Hall angle of over 6%. In addition, the anomalous Nernst effect produces a significant transverse voltage at room temperature without a magnetic field, displaying unique temperature dependence with a maximum transverse Seebeck coefficient of 440 nV K-1 and a Nernst angle of ≈62%. Such an innovative thermoelectric signal arises from the efficient thermo-spin conversion effect, where the up-spin and down-spin electrons move in opposite directions under a temperature gradient. The present study highlights the potential of FeGaTe to enhance thermoelectric devices through efficient thermo-spin conversion without the need for a magnetic field.

The Impact of Vp-Porin, an Outer Membrane Protein, on the Biological Characteristics and Virulence of Vibrio Parahaemolyticus.

Porins are crucial proteins located in the outer membrane that directly influence antimicrobial resistance mechanisms and virulence in bacteria. In this study, a porin gene (Vp-porin) was cloned in V. parahaemolyticus, and the function of Vp-Porin in biological characteristics and virulence was investigated. The results of sequence analysis showed that Vp-Porin is highly conserved in Vibrio spp., and the predicted 3D structure showed it could form a 20-strand transmembrane ß-barrel domian. Membrane permeabilization provides evidence that the membrane integrity of ∆Vp-porin was damaged and the sensitivity to tetracycline, polymyxin B, rifampicin and cephalothin of ∆Vp-porin obviously increased. In addition, loss of Vp-porin damaged motility due to downregulated flagellar synthesis. In addition, ∆Vp-porin exhibited attenuated cytotoxicity to Tetrahymena. The relative survival rate of Tetrahymena infection with ∆Vp-porin was 86%, which is much higher than that with WT (49%). Taken together, the results of this study indicate that Vp-Porin in V. parahaemolyticus plays various roles in biological characteristics in membrane integrity, antimicrobial resistance and motility and contributes to virulence.

Electric Field Switching of Magnon Spin Current in a Compensated Ferrimagnet.

Manipulation of directional magnon propagation, known as magnon spin current, is essential for developing magnonic devices featuring nonvolatile functionalities and ultralow power consumption. Magnon spin current can usually be modulated by magnetic field or current-induced spin torques. However, these approaches may lead to energy dissipation due to Joule heating. Electric-field switching of magnon spin current without charge current is highly preferred but challenging to realize. By integrating magnonic and piezoelectric materials, the manipulation of the magnon spin current generated by the spin Seebeck effect in the ferrimagnetic insulator Gd3Fe5O12 (GdIG) film on a piezoelectric substrate is demonstrated. Reversible electric-field switching of magnon polarization without applied charge current is observed. Through strain-mediated magnetoelectric coupling, the electric field induces the magnetic compensation transition between two magnetic states of the GdIG, resulting in its magnetization reversal and the simultaneous switching of magnon spin current. This work establishes a prototype material platform that paves the way for developing magnon logic devices characterized by all electric field reading and writing and reveals the underlying physics principles of their functions.

Lung cancer cell-intrinsic IL-15 promotes cell migration and sensitizes murine lung tumors to anti-PD-L1 therapy.

BACKGROUND: IL-15 plays a vital role in enhancing NK cell- and T-cell-mediated antitumor immune responses; however, the direct effect of IL-15 on tumor cells has not been fully elucidated. Herein, we investigated the effect of IL-15 on lung adenocarcinoma cells. METHODS: Silencing and overexpression techniques were used to modify endogenous IL-15 expression in tumor cells. Transwell assays were used to assess tumor cell migration and invasion; a live-cell analysis system was used to evaluate cell motility; cellular morphological changes were quantified by confocal fluorescence microscopy; the molecular mechanisms underlying the effect of IL-15 on tumor cells were analyzed by western blotting; and RhoA and Cdc42 activities were evaluated by a pulldown assay. NCG and C57BL/6 mouse models were used to evaluate the functions of IL-15 in vivo. RESULTS: Cancer cell-intrinsic IL-15 promoted cell motility and migration in vitro and metastasis in vivo via activation of the AKT-mTORC1 pathway; however, exogenous IL-15 inhibited cell motility and migration via suppression of the RhoA-MLC2 axis. Mechanistic analysis revealed that both the intracellular and extracellular IL-15-mediated effects required the expression of IL-15Rα by tumor cells. Detailed analyses revealed that the IL-2/IL-15Rß and IL-2Rγ chains were undetected in the complex formed by intracellular IL-15 and IL-15Rα. However, when exogenous IL-15 engaged tumor cells, a complex containing the IL-15Rα, IL-2/IL-15Rß, and IL-2Rγ chains was formed, indicating that the differential actions of intracellular and extracellular IL-15 on tumor cells might be caused by their distinctive modes of IL-15 receptor engagement. Using a Lewis lung carcinoma (LLC) metastasis model, we showed that although IL-15 overexpression facilitated the lung metastasis of LLC cells, IL-15-overexpressing LLC tumors were more sensitive to anti-PD-L1 therapy than were IL-15-wild-type LLC tumors via an enhanced antitumor immune response, as evidenced by their increased CD8+ T-cell infiltration compared to that of their counterparts. CONCLUSIONS: Cancer cell-intrinsic IL-15 and exogenous IL-15 differentially regulate cell motility and migration. Thus, cancer cell-intrinsic IL-15 acts as a double-edged sword in tumor progression. Additionally, high levels of IL-15 expressed by tumor cells might improve the responsiveness of tumors to immunotherapies.

CD4+ Cytotoxic T Lymphocytes in Cancer Immunity and Immunotherapy.

CD4+ T cells have the ability to differentiate into relatively specialized effector subsets after exposure to innate immune signals. The remarkable plasticity of CD4+ T cells is required to achieve immune responses in different tissues and against various pathogens. Numerous studies have shown that CD4+ T cells can play direct and indispensable roles in protective immunity by killing infected or transformed cells. Although the lineage decision of commitment to the CD4+ or CD8+ cell lineage is once thought to be inflexible, the identification of antigen-experienced CD4+ T cells with cytotoxic activity suggests the existence of unexpected plasticity for these cells. The recognition of CD4+ cytotoxic T lymphocytes (CTLs) and the mechanisms driving the differentiation of this particular cell subset create opportunities to explore the roles of these effector cells in protective immunity and immune-related pathology. CD4+ CTLs are proven to play a protective role in antiviral immunity. Here, the latest investigations on the phenotypic and functional features of CD4+ CTLs and their roles in antitumor immunity and immunotherapy are briefly reviewed.

Distinct cellular immune profiles in lung adenocarcinoma manifesting as pure ground glass opacity versus solid nodules.

INTRODUCTION: Ground glass opacity featured lung adenocarcinomas (GGO-LUAD) display more indolent biological behavior than solid nodule featured lung adenocarcinomas (SN-LUAD) and have an excellent prognosis. However, the cellular immune characteristics of GGO-LUAD remain poorly understood. METHODS: Immunohistochemistry technique was performed to stain related immune markers (CD8, CD103, CD20, CD138, CD4, FOXP3, CD68, CD163, PD-1 and PD-L1) and TGF-ß from 15 patients with pure GGO-LUAD and 15 patients with SN-LUAD tissue sections (Paired cohort), and then, the related markers with significant differences were verified on 10 patients (Verified cohort) with both pure GGO-LUAD and SN-LUAD. For localization analysis of CD68 + tumor-associated macrophages (TAMs) and FOXP3 + Terg cells in tumor areas, pure GGO-LUAD and SN-LUAD were also stained for simultaneous detection of pan-CK, CD68 and FOXP3 by multiplex immunofluorescence. RESULTS: In the Paired cohort, compared with SN-LUAD, only the infiltration of TAMs and Treg cells was significantly lower in GGO-LUAD. The infiltration of the remaining immune cells including CD8 + T cells, CD4 + T cells, CD103 + T cells, CD20 + B cells and CD138 + Plasma cells in GGO-LUAD, although relatively low, was not significantly different. Meanwhile, the expression of TGF-ß was significantly higher in SN-LUAD. And the above results have also been confirmed in the Verified cohort. Moreover, there was no significantly difference in PD-L1 expression in GGO-LUAD compared to SN-LUAD both in the Paired cohort and Verified cohort. CONCLUSIONS: GGO-LUAD demonstrates an overall less active immune landscape as compared with SN-LUAD. TAMs and TGF-ß may play an important role in the progression of GGO-LUAD. More importantly, PD-L1 expression in GGO-LUAD is comparable to that in SN-LUAD, indicating that there may be other reasons for the insensitivity of GGO-LUAD to immunotherapy.

TGFß Antagonizes IFNγ-Mediated Adaptive Immune Evasion via Activation of the AKT-Smad3-SHP1 Axis in Lung Adenocarcinoma.

IFNγ-mediated signaling in tumor cells can induce immunosuppressive responses and cause tumor resistance to immunotherapy. Blocking TGFß promotes T lymphocyte infiltration and turns immunologically cold tumors into hot tumors, thereby improving the efficacy of immunotherapy. Several studies have shown that TGFß inhibits IFNγ signaling in immune cells. We thus sought to determine whether TGFß affects IFNγ signaling in tumor cells and plays a role in the development of acquired resistance to immunotherapy. TGFß stimulation of tumor cells increased SHP1 phosphatase activity in an AKT-Smad3-dependent manner, decreased IFNγ-mediated tyrosine phosphorylation of JAK1/2 and STAT1, and suppressed the expression of STAT1-dependent immune evasion-related molecules, e.g., PD-L1, IDO1, herpes virus entry mediator (HVEM), and galectin-9 (Gal-9). In a lung cancer mouse model, dual blockade of TGFß and PD-L1 led to superior antitumor activity and prolonged survival compared with anti-PD-L1 therapy alone. However, prolonged combined treatment resulted in tumor resistance to immunotherapy and increased expression of PD-L1, IDO1, HVEM, and Gal-9. Interestingly, after initial anti-PD-L1 monotherapy, dual TGFß and PD-L1 blockade promoted both immune evasion gene expression and tumor growth compared with that in tumors treated with continuous PD-L1 monotherapy. Alternatively, treatment with JAK1/2 inhibitor following initial anti-PD-L1 therapy effectively suppressed tumor growth and downregulated immune evasion gene expression in tumors, indicating the involvement of IFNγ signaling in immunotherapy resistance development. These results demonstrate an unappreciated effect of TGFß on the development of IFNγ-mediated tumor resistance to immunotherapy. SIGNIFICANCE: Blocking TGFß facilitates IFNγ-mediated resistance to anti-PD-L1 therapy due to the role of TGFß in inhibiting IFNγ-induced immunoevasion by increasing SHP1 phosphatase activity in tumor cells.

Recent Progress of Atomic Layer Technology in Spintronics: Mechanism, Materials and Prospects.

The atomic layer technique is generating a lot of excitement and study due to its profound physics and enormous potential in device fabrication. This article reviews current developments in atomic layer technology for spintronics, including atomic layer deposition (ALD) and atomic layer etching (ALE). To begin, we introduce the main atomic layer deposition techniques. Then, in a brief review, we discuss ALE technology for insulators, semiconductors, metals, and newly created two-dimensional van der Waals materials. Additionally, we compare the critical factors learned from ALD to constructing ALE technology. Finally, we discuss the future prospects and challenges of atomic layer technology in the field of spinronics.

Significant Modulation of Vortex Resonance Spectra in a Square-Shape Ferromagnetic Dot.

The resonance property of a magnetic vortex contained within a micron-sized square Py dot was detected using an amplitude-modulated magnetic field excitation technique. We found a significant modulation of the resonant spectra as the external magnetic field changes. The Lorentzian-like spectrum changes from a peak to a dip via a transition of anti-Lorentzian-like spectra. By conducting the micromagnetic simulations, we confirmed that the transition behavior results from the unusual resistance change depending on the vortex core center position. Additionally, the power dependence of the anti-Lorentzian-like spectra revealed a fairly persistent coexistence of peak and dip. Thus, the tunable spectra suggest one way to develop an integratable radiofrequency microcircuits.

Application of electromagnetic navigation bronchoscopy-guided microwave ablation in multiple pulmonary nodules: a single-centre study.

OBJECTIVES: Electromagnetic navigation bronchoscopy (ENB)-guided microwave ablation is a minimally invasive technology for treating pulmonary lesions. This study analysed the short-term safety and efficacy of ENB-guided microwave ablation in multiple pulmonary nodules (MPNs). METHODS: This retrospective study reports a single-centre experience with ENB-guided microwave ablation for MPNs. Clinical, surgical and pathological data were obtained for patients who underwent ENB-guided microwave ablation from 23 December 2019 to 23 June 2021. The primary end points were technical safety and efficiency. RESULTS: The study assessed 65 patients who underwent ENB-guided microwave ablation, 57 of whom simultaneously underwent video-assisted thoracic surgery. In total, 216 nodules were treated. Of 96 nodules treated by ENB-guided microwave ablation, 94 nodules had ground-glass opacity. Ablation efficiency was confirmed by hybrid cone-beam computed tomography. Of 120 nodules surgically removed, 106 nodules had ground-glass opacity. The mean nodule size was 7.9 mm in ablated nodules and 10.2 mm in resected nodules. Distance between nodules and pleura or fissure was 17.45 mm in ablated nodules and 7.29 mm in resected nodules. The overall malignancy rate was 47.7% (103/216); the complication rate was low (65 patients). At short-term follow-up, the post-ablation target zone shrank by 1 week and stabilized after 4-6 months. No local recurrence or enlargement of other pulmonary nodules was noted. CONCLUSIONS: To treat MPNs, ENB-guided microwave ablation is safe and efficient. The combination of this treatment and video-assisted thoracic surgery is a potential application, which can preserve as much pulmonary function as possible and treat MPNs to the maximum extent.

IFN-γ activates the tumor cell-intrinsic STING pathway through the induction of DNA damage and cytosolic dsDNA formation.

Stimulator of interferon genes (STING) pathway activation predicts the effectiveness of targeting the PD-1/PD-L1 axis in lung cancer. Active IFN-γ signaling is a common feature in tumors that respond to PD-1/PD-L1 blockade. The connection between IFN-γ and STING signaling in cancer cells has not been documented. We showed that IFN-γ caused DNA damage and the accumulation of cytosolic dsDNA, leading to the activation of the cGAS- and IFI16-dependent STING pathway in lung adenocarcinoma cells. IFN-γ-induced iNOS expression and nitric oxide production were responsible for DNA damage and STING activation. Additional etoposide treatment enhanced IFN-γ-induced IFN-ß and CCL5 expression. Tumor-infiltrating T cells stimulated with a combination of anti-CD3 and anti-PD-1 antibodies caused STING activation and increased IFN-ß and CCL5 expression in lung adenocarcinoma. These effects were abrogated by the addition of an IFN-γ neutralizing antibody. Our results suggest that the activation of tumor-infiltrating T cells could alter the tumor microenvironment via the IFN-γ-mediated activation of STING signaling in cancer cells.

Electromagnetic Navigation Bronchoscopy-Guided Microwave Ablation Combined With Uniportal Video-Assisted Thoracoscopic Surgery for Multiple Ground Glass Opacities.

BACKGROUND: An increasing number of patients are being diagnosed with multiple ground glass opacities (GGOs), but a consensus on the treatment of these patients is still lacking. The aim of this study was to investigate the safety and feasibility of a novel technique, electromagnetic navigation bronchoscopy (ENB)-guided microwave ablation combined with uniportal video-assisted thoracoscopic surgery in patients with multiple GGOs. METHODS: The clinical, radiographic, surgical, and pathologic data of patients with multiple GGOs who underwent ENB-guided microwave ablation combined with uniportal video-assisted thoracoscopic surgery from October 2018 to December 2019 were reviewed. RESULTS: Eleven patients with multiple GGOs underwent ENB-guided microwave ablation combined with uniportal video-assisted thoracoscopic surgery; they included 6 men and 5 women with a mean age of 61.3 ± 5.1 years (range, 53 to 68). Thirty-seven lesions were observed in the 11 patients, 21 of which were microwave ablated and 16 of which were surgically resected. Only 1 patient had postoperative pneumothorax and subcutaneous emphysema and was successfully discharged from the hospital after symptomatic treatment. The success rate and the efficiency of microwave ablation under ENB guidance were both 100%, with no other serious complications or procedure-related deaths occurring. No local metastasis or recurrence occurred in any patients during the follow-up period. CONCLUSIONS: Electromagnetic navigation bronchoscopy-guided microwave ablation combined with uniportal video-assisted thoracoscopic surgery is safe and feasible in patients with multiple GGOs suspected of having multiple primary lung cancers, and may represent an alternative approach for more patients, particularly patients who cannot tolerate the simultaneous resection of multiple tumors.

IFN-γ-induced ER stress impairs autophagy and triggers apoptosis in lung cancer cells.

Interferon-gamma (IFN-γ) is a major effector molecule of immunity and a common feature of tumors responding to immunotherapy. Active IFN-γ signaling can directly trigger apoptosis and cell cycle arrest in human cancer cells. However, the mechanisms underlying these actions remain unclear. Here, we report that IFN-γ rapidly increases protein synthesis and causes the unfolded protein response (UPR), as evidenced by the increased expression of glucose-regulated protein 78, activating transcription factor-4, and c/EBP homologous protein (CHOP) in cells treated with IFN-γ. The JAK1/2-STAT1 and AKT-mTOR signaling pathways are required for IFN-γ-induced UPR. Endoplasmic reticulum (ER) stress promotes autophagy and restores homeostasis. Surprisingly, in IFN-γ-treated cells, autophagy was impaired at the step of autophagosome-lysosomal fusion and caused by a significant decline in the expression of lysosomal membrane protein-1 and -2 (LAMP-1/LAMP-2). The ER stress inhibitor 4-PBA restored LAMP expression in IFN-γ-treated cells. IFN-γ stimulation activated the protein kinase-like ER kinase (PERK)-eukaryotic initiation factor 2a subunit (eIF2α) axis and caused a reduction in global protein synthesis. The PERK inhibitor, GSK2606414, partially restored global protein synthesis and LAMP expression in cells treated with IFN-γ. We further investigated the functional consequences of IFN-γ-induced ER stress. We show that inhibition of ER stress significantly prevents IFN-γ-triggered apoptosis. CHOP knockdown abrogated IFN-γ-mediated apoptosis. Inhibition of ER stress also restored cyclin D1 expression in IFN-γ-treated cells. Thus, ER stress and the UPR caused by IFN-γ represent novel mechanisms underlying IFN-γ-mediated anticancer effects. This study expands our understanding of IFN-γ-mediated signaling and its cellular actions in tumor cells.

Effects of apoptosis on liver aging.

As an irreversible and perennial process, aging is accompanied by functional and morphological declines in organs. Generally, aging liver exhibits a decline in volume and hepatic blood flow. Even with a preeminent regenerative capacity to restore its functions after liver cell loss, its biosynthesis and metabolism abilities decline, and these are difficult to restore to previous standards. Apoptosis is a programmed death process via intrinsic and extrinsic pathways, in which Bcl-2 family proteins and apoptosis-related genes, such as p21 and p53, are involved. Apoptosis inflicts both favorable and adverse influences on liver aging. Apoptosis eliminates transformed abnormal cells but promotes age-related liver diseases, such as nonalcoholic fatty liver disease, liver fibrosis, cirrhosis, and liver cancer. We summarize the roles of apoptosis in liver aging and age-related liver diseases.

Roles of aging in sleep.

With aging, various factors deteriorate the normal sleep process that is essential for the restoration of functional and physical performance. Due to aging-related diseases, life changes, or aging itself, disturbances in normal sleep cycles can profoundly affect healthy aging. To understand the interconnections between aging and the factors influencing sleep, with emerging evidence accumulated in recent years, this study elaborates on the roles of aging in sleep from four perspectives: cortical thinning, white matter degeneration, neurotransmitter dysregulation, and circadian disorganization. In brief, with aging, cortical thinning can be induced by the deposition of neurotoxic substances, and white matter degeneration can be induced by vascular abnormalities. These alterations emerging in the brain jointly disrupt sleep spindles and slow waves, leading to sleep disturbances. Age-related dysregulation in neurotransmitters (including galanin, orexin, serotonin, and adenosine) directly impairs the sleep modulation system. Disorganization in the circadian system consisting of suprachiasmatic nucleus dysfunction, reduced light transmission, and local circadian clock disruption collectively interrupts circadian rhythms, also causing sleep disturbances in the older. Of note is the bidirectional relationship between aging and sleep, which required us to examine this issue from different perspectives.

Apoptosis in the aging liver.

Various changes in the liver during aging can reduce hepatic function and promote liver injury. Aging is associated with high morbidity and a poor prognosis in patients with various liver diseases, including nonalcoholic fatty liver disease, hepatitis C and liver cancer, as well as with surgeries such as partial hepatectomy and liver transplantation. In addition, apoptosis increases with liver aging. Because apoptosis is involved in regeneration, fibrosis and cancer prevention during liver aging, and restoration of the appropriate level of apoptosis can alleviate the adverse effects of liver aging, it is important to understand the mechanisms underlying this process. Herein, we elaborate on the causes of apoptosis during liver aging, with a focus on oxidative stress, genomic instability, lipotoxicity, endoplasmic reticulum stress, dysregulation of nutrient sensing, and liver stem/progenitor cell activity.