Viruses adapt and modulate cellular pathways to allow their replication in host cells. The catabolic pathway of macroautophagy, for simplicity referred to as autophagy, is no exception. In this review, we discuss anti-viral functions of both autophagy and select components of the autophagy machinery, and how viruses have evaded them. Some viruses use the membrane remodeling ability of the autophagy machinery to build their replication compartments in the cytosol or efficiently egress from cells in a non-lytic fashion. Some of the autophagy machinery components and their remodeled membranes can even be found in viral particles as envelopes or single membranes around virus packages that protect them during spreading and transmission. Therefore, studies on autophagy regulation by viral infections can reveal functions of the autophagy machinery beyond lysosomal degradation of cytosolic constituents. Furthermore, they can also pinpoint molecular interactions with which the autophagy machinery can most efficiently be manipulated, and this may be relevant to develop effective disease treatments based on autophagy modulation.

Copper is a vital cofactor in various enzymes, plays a pivotal role in maintaining cell homeostasis. When copper metabolism is disordered and mitochondrial dysfunction is impaired, programmed cell death such as apoptosis, paraptosis, pyroptosis, ferroptosis, cuproptosis, autophagy and necroptosis can be induced. In this review, we focus on the metabolic mechanisms of copper. In addition, we discuss the mechanism by which copper induces various programmed cell deaths. Finally, this review examines copper's involvement in prevalent kidney diseases such as acute kidney injury and chronic kidney disease. The findings indicate that the use of copper chelators or plant extracts can mitigate kidney damage by reducing copper accumulation, offering novel insights into the pathogenesis and treatment strategies for kidney diseases.

Regulated cell death (such as apoptosis, necroptosis, pyroptosis, autophagy, cuproptosis, ferroptosis, disulfidptosis) involves complex signaling pathways and molecular effectors, and has been proven to be an important regulatory mechanism for regulating neuronal aging and death. However, excessive activation of regulated cell death may lead to the progression of aging-related diseases. This review summarizes recent advances in the understanding of seven forms of regulated cell death in age-related diseases. Notably, the newly identified ferroptosis and cuproptosis have been implicated in the risk of cognitive impairment and neurodegenerative diseases. These forms of cell death exacerbate disease progression by promoting inflammation, oxidative stress, and pathological protein aggregation. The review also provides an overview of key signaling pathways and crosstalk mechanisms among these regulated cell death forms, with a focus on ferroptosis, cuproptosis, and disulfidptosis. For instance, FDX1 directly induces cuproptosis by regulating copper ion valency and dihydrolipoamide S-acetyltransferase aggregation, while copper mediates glutathione peroxidase 4 degradation, enhancing ferroptosis sensitivity. Additionally, inhibiting the Xc- transport system to prevent ferroptosis can increase disulfide formation and shift the NADP + /NADPH ratio, transitioning ferroptosis to disulfidptosis. These insights help to uncover the potential connections among these novel regulated cell death forms and differentiate them from traditional regulated cell death mechanisms. In conclusion, identifying key targets and their crosstalk points among various regulated cell death pathways may aid in developing specific biomarkers to reverse the aging clock and treat age-related neurodegenerative conditions.

Precise tumor therapy is essential for improving treatment specificity, enhancing efficacy, and minimizing side effects. Targeting organelles is a key strategy for achieving this goal and is a frontier research area attracting a considerable amount of attention. The concept of organelle targeting has a significant effect on the structural design of the nanodrugs employed. Most notably, the intricate interactions among different organelles in a tumor cell essentially create a unified system. Unfortunately, this aspect might have been somewhat overlooked when existing organelle-targeting nanodrugs were designed. In this review, we underscore the synergistic relationship among the various organelles and advocate for a holistic view of organelle-targeting design. Through the integration of biology and material science, recent advancements in organelle targeting, escaping, and collaborating are consolidated to offer fresh perspectives for the development of antitumor nanomedicines.

Selective autophagy plays a crucial role in maintaining cellular homeostasis by specifically targeting unwanted cargo labeled with "autophagy cues" signals for autophagic degradation. In this study, we identify Rab GTPases as a class of such autophagy cues signals involved in selective autophagy. Through biochemical and imaging screens, we reveal that human Rab GTPases are common autophagy substrates. Importantly, we confirm the conservation of Rab GTPase autophagic degradation in different model organisms. Rab GTPases translocate to damaged mitochondria, lipid droplets, and invading Salmonella-containing vacuoles (SCVs) to serve as degradation signals. Furthermore, they facilitate mitophagy, lipophagy, and xenophagy, respectively, by recruiting receptors. This interplay between Rab GTPases and receptors may ensure the de novo synthesis of isolation membranes around Rab-GTPase-labeled cargo, thereby mediating selective autophagy. These processes are further influenced by upstream regulators such as LRRK2, GDIs, and RabGGTase. In conclusion, this study unveils a conserved mechanism involving Rab GTPases as autophagy cues signals and proposes a model for the spatiotemporal control of selective autophagy.

Cerebral ischemia/reperfusion (IR) after ischemic stroke causes deleterious microglial activation. Lysosomal associated membrane protein 3 (LAMP-3) has been indicated play a role in autophagy, yet the specific role of LAMP3 in microglia autophagy during cerebral ischemia and reperfusion (I/R) injury (CIRI) is unknown.

The oxygen-glucose deprivation/reperfusion (OGD/R) model and middle cerebral artery occlusion/reperfusion (MCAO/R) model were established. Changes in autophagy levels were detected through Western blot, immunohistochemistry, transmission electron microscopy, and laser scanning confocal microscopy. Oxidative stress damage in neurons was assessed using ROS and LDH assays. Cytokine levels (IL-6, IL-10, TNF-α, and IL-13) were measured using RT-qPCR and ELISA assays. HMC3, SH-SY5Y cell viability was evaluated using CCK8, EdU staining, Calcein/PI staining, and Transwell assays. Apoptosis was detected via TUNEL staining and flow cytometry. The role of LAMP3 in neuronal function post-cerebral ischemia-reperfusion was further investigated by administering rapamycin and BAY 11-7082.

LAMP3 expression is decreased in IS, and negatively correlated with LC3B expression. In the HMC3 OGD/R model, LAMP3 inhibits microglial autophagy, and induces oxidative stress damage and inflammatory response in HMC3 cells through the NF-κB pathway. In co-culture system of HMC3 and SH-SY5Y cells, LAMP3 inhibits neuronal autophagy and activity through the NF-κB pathway under OGD/R conditions. In vivo, overexpression of LAMP3 inhibits autophagy and exacerbates brain tissue damage after MCAO/R.

During cerebral ischemia-reperfusion, LAMP3 inhibits autophagy in microglia and neurons by activating the NF-κB pathway, thereby inducing oxidative stress and inflammatory factor release, promoting neuronal death. Treatment targeting microglial LAMP3 might be a potential therapeutic strategy for ischemic stroke treatment.

Pneumonia is a frequent-occurring event in children death. Vitamin D (VD) can alleviate inflammatory response and it might be a promising adjunct to antibiotics for the treatment of acute childhood pneumonia. This study intended to uncover the relevant mechanism of VD in pneumonia. For simulating inflammatory condition, BEAS-2B cells were induced using lipopolysaccharide (LPS). Cell viability was detected using cell counting kit-8 (CCK-8) method, and cell apoptosis was detected using flow cytometry and western blot. Inflammatory cytokines as well as oxidative stress markers were detected using enzyme-linked immunosorbent assay (ELISA) and corresponding assays. Western blot evaluated the contents of cathepsin D (CTSD), apoptosis- and autophagy-related proteins. Through real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) and western blot, the transfection efficiency of overexpression (OV)-CTSD was detected. Immunofluorescence assay detected light chain 3 (LC3II) level. Through SuperPred database analysis, VD can target CTSD. VD was revealed to suppress viability damage, inflammatory response, oxidative stress, and autophagy injury in BEAS-2B cells induced by LPS via targeting CTSD. However, the protective effects exhibited by VD against LPS-induced viability damage, inflammatory response, and oxidative stress in BEAS-2B cells were all counteracted by autophagy inhibitor 3-methyladenine (3-MA). Collectively, VD alleviated the severity of LPS-induced lung injury by promoting autophagy through targeting CTSD.

Hemoglobin-based carbon monoxide carrier (HBCOC) can dissociate carbon monoxide and ameliorate organ damage by inhibiting inflammation and oxidative stress. In this study, we evaluated its effect on cerebral ischemia-reperfusion injury in mice and explored its potential mechanism.

A middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was established using the wire embolization method, and HBCOC or equivalent normal saline was administered via the tail vein during reperfusion. HE staining and TEM were used to observe the injury in the tissue. The levels of IL-1β, IL-6, TNF-α were detected by ELISA and RT-qPCR, meantime, western blotting were used to detect expressions of TREM-1, ERK, NF-κB,LC3 and P62.

We found that the HBCOC treatment alleviated nerve injury and reduced the cerebral infarction area caused by ischemia-reperfusion, simultaneously lowered the expression of IL-1β, IL-6, and TNF-α in plasma and brain tissues. HBCOC suppressed the levels of LC3II, lysosomes, and autophagy in the brain, suggesting potent inhibition of autophagy. Mechanistic analysis indicated that the expression of TREM-1/ERK/NF-κB pathway-related proteins and mRNA was higher in the saline group than that in the HBCOC group. HBCOC combined with the targeting TREM-1 receptor inhibitors LP17 inhibited the expression of the TREM-1 protein, further reducing the release of inflammatory factors and autophagy, restoring nerve function and infarct area after reperfusion, and exerting an overall protective effect against cerebral reperfusion injury. In summary, our results indicated that HBCOC alleviated cerebral ischemia-reperfusion injury in mice and inhibited inflammation and autophagy via TREM-1.

Dysregulated autophagy has been implicated in the pathogenesis of numerous diseases, including cancer. Despite extensive research on the underlying mechanisms of autophagy, the involvement of long non-coding RNAs (lncRNAs) remains poorly understood. Here, we demonstrate that a previously identified lncRNA, HITT (HIF-1α inhibitor at the translation level), is closely associated with biological processes such as autophagy through unbiased bioinformatic analysis. Subsequent studies demonstrate that HITT is increased by several autophagic stimuli, including PI-103, a potent inhibitor of PI3K and mTOR. This is caused by a reduction in the binding between HITT and AGO2, resulting in a reduction in the activity of miR-205 towards HITT degradation. Increased HITT then binds to a key autophagy protein, Autophagy-related 5 (ATG5), and inhibits autophagosome formation by preventing the formation of the ATG12-ATG5-ATG16L1 complex. This results in HITT sensitizing PI-103-mediated cell death both in vitro and in vivo in nude mice by attenuating protective autophagy. The data presented herein demonstrate that HITT is a newly identified RNA regulator of autophagy and that it can be used to sensitize the colon cancer response to cell death by blocking the protective autophagy.

Silicosis, caused by the inhalation of silicon dioxide (SiO2), is one of the most pressing public health problems. Nevertheless, there is currently no effective treatment. This study employed male C57BL/6 J mice and mouse alveolar macrophage cell line MH-S to investigate the biological mechanism in the development of silicosis, with a view to exploring the potential applications of puerarin (Pue) in the improvement of pulmonary inflammation and fibrosis in SiO2-exposed mice. This study elucidated that SiO2 could induce expression of inflammatory factors, accompanied by autophagy flux block, lysosome alkalization and membrane permeability in MH-S cells. Pue pretreatment could effectively inhibit expression of inflammatory factors in SiO2-exposed MH-S cells via alleviating autophagolysosomal dysfunction, and suppress TGF-β-induced myofibroblast differentiation. In addition, Pue was also been demonstrated to mitigate autophagolysosomal dysfunction, pulmonary inflammation and fibrosis in SiO2-exposed C57BL/6 J mice. Furthermore, the ingestion of Pue-enriched pueraria lobata tea (Plt), a traditional Chinese tea substitute that possesses anti-inflammatory, antioxidant, and cardiovascular benefits, was determined to improve imbalance of lysosome homeostasis, pulmonary inflammation and fibrosis in SiO2-exposed mice. This study illustrates the anti-inflammatory and antifibrotic properties of Pue and Plt by alleviating autophagolysosomal dysfunction and, consequently, reducing pulmonary inflammation and fibrosis. These findings provide insights into the pathogenesis mechanism of silicosis and indicate potential avenues for application of Pue and Plt in the mitigation of silicosis.

Autophagy is a crucial cellular process that facilitates the degradation of damaged organelles and protein aggregates, and the recycling of cellular components for the energy production and macromolecule synthesis. It plays an indispensable role in maintaining cellular homeostasis. Over recent decades, research has increasingly focused on the role of autophagy in regulating adult stem cells (SCs). Studies suggest that autophagy modulates various cellular processes and states of adult SCs, including quiescence, proliferation, self-renewal, and differentiation. The primary role of autophagy in these contexts is to sustain homeostasis, withstand stressors, and supply energy. Notably, the dysfunction of adult SCs during aging is correlated with a decline in autophagic activity, suggesting that autophagy is also involved in SC- and aging-associated disorders. Given the diverse cellular processes mediated by autophagy and the intricate mechanisms governing adult SCs, further research is essential to elucidate both universal and cell type-specific regulatory pathways of autophagy. This review discusses the role of autophagy in regulating adult SCs during quiescence, proliferation, self-renewal, and differentiation. Additionally, it summarizes the relationship between SC aging and autophagy, providing therapeutical insights into treating and ameliorating aging-associated diseases and cancers, and ultimately promoting longevity.

Chronic stress remodels brain homeostasis, in which persistent change leads to depressive disorders1. As a key modulator of brain homeostasis2, it remains elusive whether and how brain autophagy is engaged in stress dynamics. Here we discover that acute stress activates, whereas chronic stress suppresses, autophagy mainly in the lateral habenula (LHb). Systemic administration of distinct antidepressant drugs similarly restores autophagy function in the LHb, suggesting LHb autophagy as a common antidepressant target. Genetic ablation of LHb neuronal autophagy promotes stress susceptibility, whereas enhancing LHb autophagy exerts rapid antidepressant-like effects. LHb autophagy controls neuronal excitability, synaptic transmission and plasticity by means of on-demand degradation of glutamate receptors. Collectively, this study shows a causal role of LHb autophagy in maintaining emotional homeostasis against stress. Disrupted LHb autophagy is implicated in the maladaptation to chronic stress, and its reversal by autophagy enhancers provides a new antidepressant strategy.

Autophagy is a conserved catabolic process that removes protein clumps and defective organelles, thereby promoting cell equilibrium. Growing data suggest that dysregulation of the autophagic pathway is linked to several cancer hallmarks. Long non-coding RNAs (lncRNAs), which are key parts of gene transcription, are increasingly recognized for their significant roles in various biological processes. Recent studies have uncovered a strong connection between the mutational landscape and altered expression of lncRNAs in the tumor formation and development, including leukemia. Research over the past few years has emphasized the role of lncRNAs as important regulators of autophagy-related gene expression. These RNAs can influence key leukemia characteristics, such as apoptosis, proliferation, epithelial-mesenchymal transition (EMT), migration, and angiogenesis, by modulating autophagy-associated signaling pathways. With altered lncRNA expression observed in leukemia cells and tissues, they hold promise as diagnostic biomarkers and therapeutic targets. The current review focuses on the regulatory function of lncRNAs in autophagy and their involvement in leukemia, potentially uncovering valuable therapeutic targets for leukemia treatment.

Autophagy plays a critical role in colitis-associated colorectal cancer (CAC). However, non-autonomous regulation of macroautophagic/autophagic flux during inflammation remains largely unexplored. Here, we show that F2rl1/Par2 deficiency (F2rl1[ΔIEC]) aggravated azoxymethane-dextran sulfate sodium-induced CAC based on tumor number and burden, promoted autophagy dysfunction characterized by SQSTM1/p62 accumulation and autophagosome-lysosome fusion inhibition in IECs, and reduced lysosomal acidification by suppressing FOXA2-induced V-ATPase ATP6V0E1 transcription. FOXA2 or ATP6V0E1 overexpression rescued autophagy impairment, reactive oxygen species accumulation, and DNA damage induced by F2RL1 deficiency in vitro and in vivo. Neutrophil-derived serine proteases suppressed FOXA2 expression, causing autophagy dysfunction. F2RL1 knockout completely blocked the effects of neutrophil proteases on FOXA2 and ATP6V0E1. The correlation between neutrophil and FOXA2-ATP6V0E1 activities was validated in ulcerative colitis and colorectal carcinoma. Therefore, F2RL1 deficiency in intestinal epithelial cells suppressed FOXA2 expression, leading to V-ATPase-mediated autophagic dysfunction and exacerbating CAC. Neutrophils may contribute to impaired autophagy and promote CAC by inactivating canonical F2RL1/PAR2 signaling via its derived proteases. F2RL1/PAR2 signaling may participate in maintaining intestinal homeostasis via autophagy. These findings provide useful insights into F2RL1/PAR2 and its cleaving serine proteases in CAC and would help in developing new therapeutic strategies for this malignancy.

Autophagy is a conserved cellular process essential for homeostasis and development that plays a central role in the degradation and recycling of cellular components. Recent studies reveal bidirectional interactions between autophagy and steroid-hormone signaling. Steroids are signaling molecules synthesized from cholesterol that regulate key physiological and developmental processes - including autophagic activity. Conversely, other work demonstrates that autophagy regulates steroid production by controlling the availability of precursor sterol substrate. Insights from Drosophila and mammalian models provide compelling evidence for the conservation of these mechanisms across species. In this review we explore how steroid hormones modulate autophagy in diverse tissues and contexts, such as metabolism and disease, and discuss advances in our understanding of autophagy's regulatory role in steroid hormone production. We examine the implications of these interactions for health and disease and offer perspectives on the potential for harnessing this functionality for addressing cholesterol-related disorders.

Ischemia-reperfusion (I/R) injury describes the pathological process wherein tissue damage, initially caused by insufficient blood supply (ischemia), is exacerbated upon the restoration of blood flow (reperfusion). This phenomenon can lead to irreversible tissue damage and is commonly observed in contexts such as cardiac surgery and stroke, where blood supply is temporarily obstructed. During ischemic conditions, the anaerobic metabolism of tissues and organs results in compromised enzyme activity. Subsequent reperfusion exacerbates mitochondrial dysfunction, leading to increased oxidative stress and the accumulation of reactive oxygen species (ROS). This cascade ultimately triggers cell death through mechanisms such as autophagy and mitophagy. Autophagy constitutes a crucial catabolic mechanism within eukaryotic cells, facilitating the degradation and recycling of damaged, aged, or superfluous organelles and proteins via the lysosomal pathway. This process is essential for maintaining cellular homeostasis and adapting to diverse stress conditions. As a cellular self-degradation and clearance mechanism, autophagy exhibits a dualistic function: it can confer protection during the initial phases of cellular injury, yet potentially exacerbate damage in the later stages. This paper aims to elucidate the fundamental mechanisms of autophagy in I/R injury, highlighting its dual role in regulation and its effects on both organ-specific and systemic responses. By comprehending the dual mechanisms of autophagy and their implications for organ function, this study seeks to explore the potential for therapeutic interventions through the modulation of autophagy within clinical settings.

Lenvatinib is the first-line therapy for inoperable HCC. However, intrinsic and acquired drug resistance occurs during the treatment period. Autophagy is an adaptive response that favors tumor survival under stress. In the present study, we aim to reveal the unknown autophagic engagement in lenvatinib resistance. Lenvatinib-resistant HCC cell lines and xenograft mouse HCC models were established to identify the key regulator of lenvatinib resistance in HCC. By in vitro functional restoration assays and autophagic flux detection, we demonstrated that the Syntaxin-6 (STX6) -mediated autophagy induced lenvatinib resistance of HCC cells. Mechanistically, Co-immunoprecipitation assay and mass spectrometry indicated that the interactions of STX6 with Beclin1, VTI1A, and VAMP3 facilitated autophagy, leading to the lenvatinib resistance. Additionally, STX6 enhanced the ability of proliferation, migration, and invasion of HCC in vitro and in vivo. Clinically, STX6 expression was significantly elevated in HCC tissues compared to it in para-tumor tissues. High STX6 expression predicted poor outcomes for patients following resection. Moreover, high expression of STX6 displayed low preventive efficacy of lenvatinib as a postoperative adjuvant treatment for HCC patients with a high risk of recurrence. Collectively, we identified that STX6-mediated autophagy plays a crucial role in lenvatinib resistance in HCC, providing a potential therapeutic target to overcome lenvatinib resistance for HCC patients.

Lung adenocarcinoma (LUAD) is marked by its considerable aggressiveness and pronounced heterogeneity. Programmed cell death (PCD) plays a pivotal role in the progression of tumors, their aggressive behavior, resistance to treatment, and recurrence of the disease.

Using expression data from 878 patients across four multicenter cohorts, we identified 13 consensus prognostic genes from 1481 genes associated with PCD. We employed 10 machine-learning algorithms, generating 101 combinations, from which the optimal algorithm was chosen to develop an artificial intelligence-derived cell death index (CDI) on the basis of the average C-index.

The training cohort and three external validation cohorts consistently demonstrated that CDI could accurately predict LUAD prognosis. Moreover, CDI showed significantly greater accuracy than traditional clinical variables, molecular characteristics, and 22 previously published signatures. Patients in the low-CDI group had a more favorable prognosis, higher levels of immune cell infiltration, better responsiveness to immunotherapy, and a higher likelihood of displaying the "hot tumor" phenotype. Single-cell analysis revealed that neutrophils had the highest CDI scores and exhibited significant differences in marker gene expression.

Pseudotime trajectory analysis indicated that BCL2L14 plays a crucial role in the developmental pathway of neutrophils, potentially influencing the fate of LUAD cells. Knockdown of BCL2L14 significantly reduced the growth, proliferation, and colony formation abilities of LUAD cells, while also enhancing apoptosis rates.

The prevalence and spread of canine influenza virus (CIV) pose a threat to the health of dogs and humans. Some studies have shown that autophagy is closely related to virus replication, but the exact relationship between CIV replication and autophagy is still unclear. Therefore, this study investigated the effects of autophagy on CIV replication in vitro and in vivo. The data showed that CIV infection significantly caused respiratory tract damage in mice, upregulated the mRNA/protein levels of CIV replication-related genes and autophagy-related genes. In addition, the activation of autophagy by rapamycin (Rapa) significantly intensified the CIV replication and the respiratory tract damage of mice, while the inhibition of autophagy by 3-Methyladenine (3-MA) significantly alleviated these effects. Data of MDCK cells also demonstrated that CIV promoted self-replication through activating autophagy, and the upregulation of AKT/mTOR by insulin significantly inhibited the CIV replication. In summary, this study showed that CIV could promote self-replication by activating AKT/mTOR mediated autophagy, which provides new ideas for the prevention and treatment of canine influenza.

Radiotherapy (RT) is one of the main therapies for hepatocellular carcinoma (HCC), but its effectiveness has been constrained due to the resistance effect of radiation. Thus, the factors involved in radioresistance are evaluated and the underlying molecular mechanisms are also done. In this present study, we identified Integrin β6 (ITGB6) as a potential radioresistant gene through an integrative analysis of transcriptomic profiles, proteome datasets and survival using HCC cases treated with IR. We show that ITGB6 functionally contributed to radioresistance by activating autophagy through a series of in vitro and in vivo methods, such as clonogenic assays, autophagy flux (LC3B-GFP-mCherry reporter) analysis and a subcutaneous transplantation model. Mechanically, ITGB6 binds to Annexin A2 (ANXA2) and enhanced its stability by competitively antagonizing proteasome mediated ANXA2 degradation, thereby promoting autophagy and radioresistance. Notably, HCC radioresistance was significantly improved by either blocking ITGB6 or autophagy, but the combination was more effective. Importantly, ITGB6/ANXA2 axis triggered autophagic program endowed HCC cells with radioresistant activity in a radiated patient-derived xenograft (PDX) model and hydrodynamic injection in liver-specific Itgb6-knockout mice, further supported by clinical evidence. Together, our data revealed that ITGB6 is a radioresistant gene stabilizing the autophagy regulatory protein ANXA2, providing insights into the biological and potentially clinical significance of ITGB6/ANXA2 axis in radiotherapy planning of HCC.

Hippocampal aromatase (AROM) knockdown induces Aβ accumulation and Alzheimer's disease (AD)-like spatial learning and memory impairment, and early hippocampal AROM overexpression in APP/PS1 mice prevents Aβ deposition and memory loss later in life. The aim of this study was to elucidate the underlying mechanism and provide novel prevention and treatment targets for AD.

AROM-inhibiting viral vectors were constructed and injected into the hippocampi of adult female mice, after which label-free LC-MS/MS proteomics and bioinformatics analysis were conducted. Additional viral vectors targeting LAMP2 or LC3 were constructed and used to treat HT22 cells. LAMP2 expression was verified, and macroautophagy levels, autophagosome formation and Aβ accumulation were examined. Additionally, ovariectomy combined with the hippocampal injection of LAMP2 inhibition/overexpression viral vectors was applied, and learning and memory abilities and Aβ accumulation were examined.

Proteomics revealed the enrichment of CMA and autophagy, and LAMP2 was the most significantly upregulated protein. Higher LAMP2 levels were correlated with lower macroautophagy and autophagosomes levels but were correlated with higher Aβ accumulation, and vice versa. Additionally, hippocampal LAMP2 mediated the effects of ovariectomy on spatial memory and Aβ accumulation.

These results demonstrated the important role of the hippocampal LAMP2-macroautophagy pathway in mediating both hippocampal and ovarian estrogen regulation of Aβ accumulation and AD-like behavior, indicating that LAMP2 might be a novel target for both hippocampal and circulating estrogen deficiency-associated memory impairments, such as AD.

Post-translational lipid modification by palmitoylation is a reversible process crucial for maintaining cellular functionality. The palmitoyl acyltransferase zinc finger Asp-His-His-Cys motif-containing 5 (ZDHHC5) has garnered significant attention due to its roles in neurodegenerative diseases, oncogenesis, and cardiac function. ZDHHC5 recognizes substrates through diverse mechanisms and its activity is regulated by multiple factors. Highly expressed in the brain, liver and heart, ZDHHC5 exerts regulatory functions in various cellular processes through self-regulation and substrate palmitoylation. This review focuses on the regulatory roles of ZDHHC5 in the nervous system including circadian rhythm, tumor, lipid metabolism. Dysfunctions in ZDHHC5 are associated with several diseases, thereby highlighting its potential as a target for novel therapeutic strategies against neurological, lipid metabolic, and oncogenesis.

Osteoarthritis is one of the most prevalent age-related joint diseases, with chondrocyte inflammation and autophagy dysregulation serving as pivotal pathogenesis factors. Andrographolide (AD), a phytochemical identified in Andrographis paniculata, exhibits anti-inflammatory properties and regulates autophagy to safeguard cells from damage. Nevertheless, the precise mechanism underlying the influence of AD on autophagy in osteoarthritis (OA) chondrocytes remains unelucidated. Concurrently, sustained efficacy of andrographolide typically necessitates prolonged administration, posing a challenge for its clinical application. We engineered an injectable 4-arm PEG-Mix-Hydrogel/PF system capable of encapsulating lipophilic drugs and achieving sustained release over a period of up to 24 days, substantially reducing the frequency of medication. Our findings indicate that andrographolide augments chondrocyte autophagy via the PRKCA/EGFR pathway and modulates chondrocyte inflammation as well as extracellular matrix degradation. Subsequent experimentation revealed that the injectable 4-arm PEG-Mix-Hydrogel/PF@AD (PHPF@AD) exhibited excellent biocompatibility with chondrocytes, possessed a rapid in-situ gelation time, and a single injection was sufficient to alleviate joint degeneration, abnormal gait, and weakened chondrocyte autophagy in OA mice, while ameliorating inflammation, matrix degradation, and apoptosis levels, and maintaining a certain degree of bone mass around the joints. In summary, this injectable hydrogel with spontaneous andrographolide release is anticipated to be a promising therapeutic modality for OA.

As an autophagy receptor, SQSTM1/p62 facilitates the degradation of various cytoplasmic components, including proteins, organelles, and pathogens, by mediating interactions between polyubiquitination cargo and autophagosomes. Our study observed an increase in the expression level of SQSTM1/p62 during autophagy induced by Vibrio alginolyticus (V. alginolyticus) in Penaeus vannamei (P. vannamei), contrary to expectations, which promoted an investigation into the role of SQSTM1/p62 in infectious diseases of aquatic animals. Using silencing techniques, we examined the function and regulatory mechanism of SQSTM1/p62 during V. alginolyticus infection. Silencing the Pvp62 gene in P. vannamei and infecting them with V. alginolyticus led to a significant decrease in the survival rate of P. vannamei, indicating its importance in the infection process. Furthermore, Pvp62 silencing was found to affect the lysosome function of P. vannamei. Immunofluorescence analysis showed that silences of Pvp62 inhibited co-localization of LC3 and lamp1 after infection, while overexpression of Pvp62 promoted this process, suggesting that Pvp62 was a necessary condition for autophagosome-lysosome fusion after infection by V. alginolyticus. Importantly, the overexpression of Pvp62 counteracted the inhibitory effect of the autophagy inhibitor chloroquine on autophagosome-lysosome fusion in primary hemocytes of shrimp after infection, underscoring the protective role of Pvp62-mediated autophagosome-lysosome fusion pathway during V. alginolyticus infection.

The age-associated decline in intestinal stem cell (ISC) function is a key factor in intestinal aging in organisms, resulting in impaired intestinal function and increased susceptibility to age-related diseases. Consequently, it is imperative to develop effective therapeutic strategies to prevent ISC aging and functional decline. In this study, we utilized an aging Drosophila model screening of amino acids and found that asparagine (Asn), a nonessential amino acid in vivo, exhibits its profound anti-aging properties on ISCs. Asn inhibits the hyperproliferation of aging ISCs in Drosophila, maintains intestinal homeostasis, and extends the lifespan of aging flies. Complementarily, Asn promotes the growth and branching of elderly murine intestinal organoids, indicating its anti-aging capacity to enhance ISC function. Mechanistic analyses have revealed that Asn exerts its effects via the activation of the autophagic signaling pathway. In summary, this study has preliminarily explored the potential supportive role of Asn in ameliorating intestinal aging, providing a foundation for further research into therapeutic interventions targeting age-related intestinal dysfunction.

Cellular senescence, a hallmark of aging, has emerged as a captivating area of research in tumor immunology with profound implications for cancer prevention and treatment. In the tumor microenvironment, senescent cells exhibit a dual role, simultaneously hindering tumor development through collaboration with immune cells and evading immune cell attacks by upregulating immunoinhibitory proteins. However, the intricate immune escape mechanism of cellular senescence in the tumor microenvironment remains a subject of intense investigation. Chronic inflammation is exacerbated by cellular senescence through the upregulation of pro-inflammatory factors such as interleukin-1β, thereby augmenting the risk of tumorigenesis. Additionally, the interplay between autophagy and cellular senescence adds another layer of complexity. Autophagy, known to slow down the aging process by reducing p53/p21 levels, may be downregulated by cellular senescence. To harness the therapeutic potential of cellular senescence, targeting its immunological aspects has gained significant attention. Strategies such as immune checkpoint inhibitors and T-cell senescence inhibition are being explored in the context of cellular senescence immunotherapy. In this comprehensive review, we provide a compelling overview of the regulation of cellular senescence and delve into the influencing factors, including chronic inflammation, autophagy, and circadian rhythms, associated with senescence in the tumor microenvironment. We specifically focus on unraveling the enigmatic dual role of cellular senescence in tumor immune escape. By deciphering the intricate nature of cellular senescence in the tumor microenvironment, this review aims to advance our understanding and pave the way for leveraging senescence as a promising target for tumor immunotherapy applications.

Autophagy is a self-eating pathway for maintaining normal cellular physiology, while dysregulation of autophagy is associated with cancer progression. Autophagy-related 4B gene (ATG4B) is a cysteine protease to regulate autophagosome formation and is positively correlated with poor prognosis of colorectal cancer (CRC) patients. An increasing number of reports have implied that ATG4B might be an attractive drug target for CRC. Natural products are the most important source of drug development for cancer therapy due to their high degree of diversity in chemical structure. However, there are few natural products targeting autophagy regulation, especially targeting ATG4B. We aim to identify effective natural compounds from costal plants against ATG4B as potential CRC therapies. We extracted the whole plants, stem, and leaves from nine coastal plant species of Taiwan using different solvents including acetone, methanol, or chloroform. We then evaluated their effects on ATG4B activity and cancer malignancy in CRC cells (DLD-1, HCT116, and SW620). Among these 26 extracts, we found that the methanol leaf extract of A. elliptifolia significantly inhibited ATG4B proteolytic activity. Moreover, cell viability and colony formation and mobility were decreased in CRC cells treated with the extract. The extract further reduced the number of living cells and induced subG1 proportion of CRC cells. The cytotoxicity of A. elliptifolia leaf extract was also enhanced in CRC cells under starvation, whereas it had no additional effects in ATG4B or autophagy deficient cells. Taken together, the methanol leaf extract of A. elliptifolia might contains bioactive compounds for inhibiting ATG4B and autophagy activity to diminish viability and mobility of CRC cells, indicating its potential as an anti-CRC drug for future development.

Metabolic disorders have been identified as one of the causes of drug-induced liver injury; however, the direct regulatory mechanism regarding this disorder has not yet been clarified. In this study, a single regulatory mechanism of small molecule kinase inhibitors, with crizotinib as the representative drug is elucidated. First, it is discovered that crizotinib induced aberrant lipid metabolism and apoptosis in the liver. A mechanistic study revealed that crizotinib treatment promoted the accumulation of squalene epoxidase (SQLE) by inhibiting autophagosome-lysosome fusion which blocked the autophagic degradation of SQLE. A maladaptive increase in SQLE led to disturbances in cholesterol and sphingolipid metabolism via an enzymatic activity-dependent manner. Abnormal cholesterol results in both steatosis and inflammatory infiltration, and disturbances in sphingolipid metabolism promote cell apoptosis by inducing lysosomal membrane permeabilization. The restoration of the level or activity of SQLE ameliorated steatosis and hepatocyte injury. The autophagy activator known as metformin or the SQLE enzymatic inhibitor known as terbinafine has potential clinical use for alleviating crizotinib hepatotoxicity.

Bone defect repair remains a great challenge in the field of orthopedics. Human body essential trace element such as copper is essential for bone regeneration, but how to use it in bone defects and the underlying its mechanisms of promoting bone formation need to be further explored. In this study, by doping copper into mesoporous bioactive glass nanoparticles (Cu-MBGNs), we unveil a previously unidentified role of copper in facilitating osteoblast mitophagy and mitochondrial dynamics, which enhance amorphous calcium phosphate (ACP) release and subsequent biomineralization, ultimately accelerating the process of bone regeneration. Specifically, by constructing conditional knockout mice lacking the autophagy gene Atg5 in osteogenic lineage cells, we first confirmed the role of Cu-MBGNs-promoted bone formation via mediating osteoblast autophagy pathway. Then, the in vitro studies revealed that Cu-MBGNs strengthened mitophagy by inducing ROS production and recruiting PINK1/Parkin, thereby facilitating the efficient release of ACP from mitochondria into matrix vesicles for biomineralization during bone regeneration. Moreover, we found that Cu-MBGNs promoted mitochondrion fission via activating dynamin related protein 1 (Drp1) to reinforce mitophagy pathway. Together, this study highlights the potential of Cu-MBGNs-mediated mitophagy and biomineralization for augmenting bone regeneration, offering a promising avenue for the development of advanced bioactive materials in orthopedic applications.

Delayed fracture healing (DFH) is a common postoperative complication in fracture patients, and a validated serum marker may aid in the clinical management and improve the prognosis of fracture patients. In this study, we investigated the diagnostic role and potential regulatory mechanisms of miR-654-3p in DFH.

73 patients with DFH and 75 patients with normal fracture healing (NFH) were included. Expression of miR-654-3p and EMP1 and several mRNA markers of osteogenic differentiation were evaluated by RT-qPCR. The diagnostic value of miR-654-3p and EMP1 alone and in combination was assessed using ROC curves. Cell proliferation capacity was assessed by CCK-8 and apoptosis rate by flow cytometry. DLR experiments demonstrated the targeting relationship between miR-654-3p and EMP1.

Levels of miR-654-3p were found to be significantly lower in DFH compared to NFH. Following cell differentiation treatment, miR-654-3p levels increased and EMP1 levels decreased. Furthermore, a negative correlation was identified between miR-654-3p and EMP1 target binding and expression levels. The combination of miR-654-3p and EMP1 holds significant diagnostic value for DFH. miR-654-3p high expression can inhibit EMP1 levels, which promotes cell proliferation, increases osteoblast activity and levels of differentiation markers, and decreases the rate of apoptosis.

miR-654-3p and EMP1 are aberrantly expressed in DFH, and both have high diagnostic value for DFH. miR-654-3p is involved in the proliferation, differentiation, and apoptotic activities of osteoblasts by regulating the level of EMP1, thus affecting the progression of DFH.

Autophagy is a lysosome-dependent degradation pathway for recycling intracellular materials and removing damaged organelles, and it is usually considered a prosurvival process in response to stress stimuli. However, increasing evidence suggests that autophagy can also drive cell death in a context-dependent manner. The bulk degradation of cell contents and the accumulation of autophagosomes are recognized as the mechanisms of cell death induced by autophagy alone. However, autophagy can also drive other forms of regulated cell death (RCD) whose mechanisms are not related to excessive autophagic vacuolization. Notably, few reviews address studies on the transformation from autophagy to RCD, and the underlying molecular mechanisms are still vague.

This review aims to summarize the existing studies on autophagy-mediated RCD, to elucidate the mechanism by which autophagy initiates RCD, and to comprehensively understand the role of autophagy in determining cell fate.

This review highlights the prodeath effect of autophagy, which is distinct from the generally perceived cytoprotective role, and its mechanisms are mainly associated with the selective degradation of proteins or organelles essential for cell survival and the direct involvement of the autophagy machinery in cell death. Additionally, this review highlights the need for better manipulation of autophagy activation or inhibition in different pathological contexts, depending on clinical purpose.

Pre-clinical evidence indicates that mitochondria may be a therapeutic target for luteolin (3',4',5,7-tetrahydroxyflavone; LUT) in different conditions. LUT modulates mitochondrial physiology in in vitro, ex vivo, and in vivo experimental models. This flavone exerted mitochondria-related antioxidant and anti-apoptotic effects, stimulated mitochondrial fusion and fission, induced mitophagy, and promoted mitochondrial biogenesis in human and animal cells and tissues. Moreover, LUT modulated the activity of components of the oxidative phosphorylation (OXPHOS) system, improving the ability of mitochondria to produce adenosine triphosphate (ATP) in certain circumstances. The mechanism of action by which LUT promoted mitochondrial benefits and protection are not completely clear yet. Nonetheless, LUT is a potential candidate to be utilized in mitochondrial therapy in the future. In this work, it is explored the mechanisms of action by which LUT modulates mitochondrial physiology in different pre-clinical experimental models.

Autophagy is a highly conserved cellular process essential for maintaining cellular homeostasis and influencing cancer development. Lysosomal acidification and autophagosome-lysosome fusion are two important steps of autophagy degradation that are tightly regulated. Although many key proteins that regulate these two events have been identified, the effector proteins that co-regulate both steps remain to be explored. ATP6AP1, an accessory subunit of V-ATPase, plays a critical role in the assembly and regulation of V-ATPase. However, the function of ATP6AP1 in autophagy remains unknown, and the role of ATP6AP1 in cancer is still poorly understood. In this study, we found that ATP6AP1 is overexpressed in luminal breast cancer tissues and promotes the proliferation and tamoxifen resistance of luminal breast cancer cells both in vitro and in vivo. We also observed that high ATP6AP1 expression correlates with poor overall patient survival. Our research further revealed that ATP6AP1 enhances tamoxifen resistance by activating autophagy. Mechanistically, ATP6AP1 promotes autophagy by regulating both lysosomal acidification and autophagosome-lysosome fusion. Remarkably, ATP6AP1 induces lysosomal acidification through the regulation of V-ATPase assembly and facilitates autophagosome-lysosome fusion by enhancing the interaction between Rab7 and the HOPS complex. Together, our studies identify ATP6AP1 as a crucial regulator of autophagy, potentially serving as a valuable prognostic marker or therapeutic target in human luminal breast cancer.

Pancreatic cancer (PC) presents significant challenges in oncology, with metastasis critically affecting patient outcomes. Autophagy-related genes (ARGs)'s involvement in influencing immune activity and metastasis in PC remains inadequately understood.

This study seeks to identify and validate five ARGs that could serve as immune targets, enhancing enhancing Pancreatic cancer metastasis (PCM)'s prognostic models and informing immunotherapy strategies.

ARGs that were diffentially expressed were screened, followed by Cox regression and LASSO analyses to pinpoint five genes linked to overall survival (OS). A prognostic model was developed and validated using ROC curves. Functional analyses, including GO and KEGG, were performed to elucidate ARG mechanisms. Immune infiltration and TFs/microRNA/mRNA networks were assessed to understand ARG-immune cell interactions. Experimental validation employed real-time PCR, IHC, and Western blotting, supported by TCGA data. Functional assays explored RHEB's role in PC, particularly its interaction with LC3.

Five ARGs (CASP1, RHEB, CHMP2B, MYC, and HDAC6) were identified, contributing to a robust prognostic model where low-risk individuals showed significantly longer OS. The model demonstrated high AUC scores, indicating strong prognostic capability. CD8 T cells and Treg cells' elevated levels were observed in metastatic subjects. RHEB knockdown suppressed cancer cell proliferation and invasion, with a negative correlation between RHEB and LC3, suggesting a role in autophagy-mediated modulation of PC metastasis.

This study introduces a novel prognostic model incorporating five ARGs, highlighting their potential as immune targets for cancer immunotherapy. The negative correlation between RHEB and LC3 suggests a therapeutic pathway for PCM intervention, laying the groundwork for more effective anti-cancer strategies. These findings advance the identification of novel immune targets and signaling pathways, aligning with precision medicine goals in cancer treatment.

Heterozygous mutations in the Bone morphogenetic protein (BMP) type I receptor ACVR1, encoding activin-like kinase 2 (ALK2), underlie all cases of the rare genetic musculoskeletal disorder Fibrodysplasia Ossificans Progressiva (FOP). The most commonly found mutant ALK2 p.R206H receptor variant exhibits loss of auto inhibition of BMP signaling and can be activated by Activins, while wild-type receptors remain unresponsive. Consequently, the downstream chondrogenic signaling is enhanced, thus driving heterotopic ossification within soft connective tissues. Despite several investigational treatments being evaluated in clinical trials, no cure for FOP exists today. The cellular and molecular mechanisms underlying disease progression are still being deciphered. In this study, we show a close interplay between the mutant ALK2R206H receptor signaling and dysregulation of the autophagic flux triggered by hypoxia. Mechanistically, reduced autophagic flux correlates with increased stability of ALK2R206H, resulting in sustained signaling. Of note, we demonstrated that Rapamycin, under clinical investigation as a treatment for FOP, inhibits chondrogenic differentiation in an autophagy-dependent manner. Consistently, other pharmacological autophagy inducers, like Spermidine, can reduce ALK2R206H driven chondrogenic differentiation in vitro. These results were verified in FOP patient-derived cells. In conclusion, this study shows that aberrant autophagic flux mediates sustained ALK2R206H signaling, introducing a novel druggable target in FOP by reactivating autophagy.

Mitophagy is an important lysosomal degradative pathway that removes damaged or unwanted mitochondria to maintain cellular and organismal homeostasis. The mechanisms behind how mitophagy is initiated to form autophagosomes around mitochondria have gained a lot of interest since they can be potentially targeted by mitophagy-inducing therapeutics. Mitophagy initiation can be driven by various autophagy receptors or adaptors that respond to different cellular and mitochondrial stimuli, ranging from mitochondrial damage to metabolic rewiring. This review will cover recent advances in our understanding of how mitophagy is initiated, and by doing so reveal the mechanistic plasticity of how autophagosome formation can begin.

The lymphatic system functions in fluid homeostasis, lipid absorption and the modulation of the immune response. The role of Gpnmb (osteoactivin), an established osteoinductive molecule with newly identified anti-inflammatory properties, has not been studied in lymphangiogenesis. Here, we demonstrate that Gpnmb increases lymphatic endothelial cell (LEC) migration and lymphangiogenesis marker gene expression in vitro by enhancing pro-autophagic gene expression, while no changes were observed in cell proliferation or viability. In addition, cellular spreading and cytoskeletal reorganization was not altered following Gpnmb treatment. We show that systemic Gpnmb overexpression in vivo leads to increases in lymphatic tubule number per area. Overall, data presented in this study suggest Gpnmb is a positive modulator of lymphangiogenesis.