Autophagy genes in biology and disease.

Macroautophagy and microautophagy are highly conserved eukaryotic cellular processes that degrade cytoplasmic material in lysosomes. Both pathways involve characteristic membrane dynamics regulated by autophagy-related proteins and other molecules, some of which are shared between the two pathways. Over the past few years, the application of new technologies, such as cryo-electron microscopy, coevolution-based structural prediction and in vitro reconstitution, has revealed the functions of individual autophagy gene products, especially in autophagy induction, membrane reorganization and cargo recognition. Concomitantly, mutations in autophagy genes have been linked to human disorders, particularly neurodegenerative diseases, emphasizing the potential pathogenic implications of autophagy defects. Accumulating genome data have also illuminated the evolution of autophagy genes within eukaryotes as well as their transition from possible ancestral elements in prokaryotes.

ZZ domains keep cytosol to vacuole delivery whiZZing along.

Selective autophagy relies on adaptor proteins to bind and transport cargos (or substrates) to the lysosome or vacuole, yet the mechanisms for cargo recognition are not well understood. In this issue, Wang et al (2021) showed that in the fission yeast, Nbr1, a homolog of a mammalian selective autophagy adaptor, recognizes vacuolar hydrolases Ams1 and Ape4 through both versatile and cargo-specific interactions with the Nbr1 ZZ1 domain.

Apoptosis-related prognostic biomarkers and potential targets for acute kidney injury based on machine learning algorithm and in vivo experiments.

Acute kidney injury (AKI) is a common critical illness in hospitalized patients, characterized by a rapid decline in kidney function over a short period, which can seriously endanger the patient's life. Currently, there is a lack of precise and universal AKI diagnostic biomarkers in clinical practice. In this study, weighted gene coexpression network analysis (WGCNA), differential expression analysis, univariate and multivariate logistic regression analyses, receiver operating characteristic (ROC) curves, and immune cell infiltration were performed to identify apoptosis-related biomarkers that can be used for AKI diagnosis. Three core apoptosis-related genes (ARGs), CBFB, EGF and COL1A1, were identified as AKI biomarkers. More importantly, an apoptosis-related signature containing three hub ARGs was validated as a diagnostic model. The hub genes exhibited good correlations with glomerular filtration rate (GFR) and serum creatinine (SCr) in the Nephroseq kidney disease database. Additionally, CIBERSORT immune infiltration analysis indicated that these core ARGs may affect immune cell recruitment and infiltration in AKI patients. Subsequently, we investigated the alteration of the expression levels of three core ARGs in AKI samples using single-cell RNA sequencing analysis and analyzed the cell types that mainly expressed these ARGs. More importantly, the expression of core ARGs was validated in folic acid- and cisplatin-induced AKI mouse models. In summary, our study identified three diagnostic biomarkers for AKI, explored the roles of ARGs in AKI progression and provided new ideas for the clinical diagnosis and treatment of AKI.

A novel mitochondrial unfolded protein response-related risk signature to predict prognosis, immunotherapy and sorafenib sensitivity in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common cause of cancer-associated death worldwide. The mitochondrial unfolded protein response (UPRmt) not only maintains mitochondrial integrity but also regulates cancer progression and drug resistance. However, no study has used the UPRmt to construct a prognostic signature for HCC. This work aimed to establish a novel signature for predicting patient prognosis, immune cell infiltration, immunotherapy, and chemotherapy response based on UPRmt-related genes (MRGs). Transcriptional profiles and clinical information were obtained from the TCGA and ICGC databases. Cox regression and LASSO regression analyses were applied to select prognostic genes and develop a risk model. The TIMER algorithm was used to investigate immunocytic infiltration in the high- and low-risk subgroups. Here, two distinct clusters were identified with different prognoses, immune cell infiltration statuses, drug sensitivities, and response to immunotherapy. A risk score consisting of seven MRGs (HSPD1, LONP1, SSBP1, MRPS5, YME1L1, HDAC1 and HDAC2) was developed to accurately and independently predict the prognosis of HCC patients. Additionally, the expression of core MRGs was confirmed by immunohistochemistry (IHC) staining, single-cell RNA sequencing, and spatial transcriptome analyses. Notably, the expression of prognostic MRGs was significantly correlated with sorafenib sensitivity in HCC and markedly downregulated in sorafenib-treated HepG2 and Huh7 cells. Furthermore, the knockdown of LONP1 decreased the proliferation, invasion, and migration of HepG2 cells, suggesting that upregulated LONP1 expression contributed to the malignant behaviors of HCC cells. To our knowledge, this is the first study to investigate the consensus clustering algorithm, prognostic potential, immune microenvironment infiltration and drug sensitivity based on the expression of MRGs in HCC. In summary, the UPRmt-related classification and prognostic signature could assist in determining the prognosis and personalized therapy of HCC patients from the perspectives of predictive, preventative and personalized medicine.

Transcription factors-related molecular subtypes and risk prognostic model: exploring the immunogenicity landscape and potential drug targets in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer, with a high mortality rate and poor prognosis. Mutated or dysregulated transcription factors (TFs) are significantly associated with carcinogenesis. The aim of this study was to develop a TF-related prognostic risk model to predict the prognosis and guide the treatment of HCC patients. METHODS: RNA sequencing data were obtained from the TCGA database. The ICGC and GEO databases were used as validation datasets. The consensus clustering algorithm was used to classify the molecular subtypes of TFs. Kaplan‒Meier survival analysis and receiver operating characteristic (ROC) analysis were applied to evaluate the prognostic value of the model. The immunogenic landscape differences of molecular subtypes were evaluated by the TIMER and xCell algorithms. Autodock analysis was used to predict possible binding sites of trametinib to TFs. RT‒PCR was used to verify the effect of trametinib on the expression of core TFs. RESULTS: According to the differential expression of TFs, HCC samples were divided into two clusters (C1 and C2). The survival time, signaling pathways, abundance of immune cell infiltration and responses to chemotherapy and immunotherapy were significantly different between C1 and C2. Nine TFs with potential prognostic value, including HMGB2, ESR1, HMGA1, MYBL2, TCF19, E2F1, FOXM1, CENPA and ZIC2, were identified by Cox regression analysis. HCC patients in the high-risk group had a poor prognosis compared with those in the low-risk group (p < 0.001). Moreover, the area under the ROC curve (AUC) values of the 1-year, 2-year and 3-year survival rates were 0.792, 0.71 and 0.695, respectively. The risk model was validated in the ICGC database. Notably, trametinib sensitivity was highly correlated with the expression of core TFs, and molecular docking predicted the possible binding sites of trametinib with these TFs. More importantly, the expression of core TFs was downregulated under trametinib treatment. CONCLUSIONS: A prognostic signature with 9 TFs performed well in predicting the survival rate and chemotherapy/immunotherapy effect of HCC patients. Trimetinib has potential application value in HCC by targeting TFs.

The evolution of autophagy proteins - diversification in eukaryotes and potential ancestors in prokaryotes.

Autophagy is a degradative pathway for cytoplasmic constituents, and is conserved across eukaryotes. Autophagy-related (ATG) genes have undergone extensive multiplications and losses in different eukaryotic lineages, resulting in functional diversification and specialization. Notably, even though bacteria and archaea do not possess an autophagy pathway, they do harbor some remote homologs of Atg proteins, suggesting that preexisting proteins were recruited when the autophagy pathway developed during eukaryogenesis. In this Review, we summarize our current knowledge on the distribution of Atg proteins within eukaryotes and outline the major multiplication and loss events within the eukaryotic tree. We also discuss the potential prokaryotic homologs of Atg proteins identified to date, emphasizing the evolutionary relationships and functional differences between prokaryotic and eukaryotic proteins.

Evolution and insights into the structure and function of the DedA superfamily containing TMEM41B and VMP1.

TMEM41B and VMP1 are endoplasmic reticulum (ER)-localizing multi-spanning membrane proteins required for ER-related cellular processes such as autophagosome formation, lipid droplet homeostasis and lipoprotein secretion in eukaryotes. Both proteins have a VTT domain, which is similar to the DedA domain found in bacterial DedA family proteins. However, the molecular function and structure of the DedA and VTT domains (collectively referred to as DedA domains) and the evolutionary relationships among the DedA domain-containing proteins are largely unknown. Here, we conduct a remote homology search and identify a new clade consisting mainly of bacterial proteins of unknown function that are members of the Pfam family PF06695. Phylogenetic analysis reveals that the TMEM41, VMP1, DedA and PF06695 families form a superfamily with a common origin, which we term the DedA superfamily. Coevolution-based structural prediction suggests that the DedA domain contains two reentrant loops facing each other in the membrane. This topology is biochemically verified by the substituted cysteine accessibility method. The predicted structure is topologically similar to that of the substrate-binding region of Na+-coupled glutamate transporter solute carrier 1 (SLC1) proteins. A potential ion-coupled transport function of the DedA superfamily proteins is discussed. This article has an associated First Person interview with the joint first authors of the paper.

Afterglow/Fluorescence Dual-Emissive Ratiometric Oxygen Probe for Tumor Hypoxia Imaging.

Hypoxia is a common feature of many diseases such as solid tumors. The measurement and imaging of oxygen (O2) are extremely important for disease diagnosis and therapy evaluation. In this work, the afterglow/fluorescence dual-emissive ratiometric O2 probe based on a photochemical reaction-based afterglow system is reported. The afterglow is highly sensitive to O2 because the O2 content is directly related to the 1O2 yield and eventually affects the afterglow intensity. The O2-insensitive fluorescence of an emitter can serve as an internal reference. As the O2 concentration changes from 0.08 to 18.5 mg L-1, the ratio value shows a remarkable 53-fold increase. Compared with the intensity of a single peak, the ratiometric signal can eliminate the interference of the probe concentration to achieve higher accuracy. This afterglow/fluorescence dual-emissive ratiometric O2 probe is successfully applied to hypoxia imaging in tumor-bearing mice, which may further promote the development of O2 sensing in the biomedical field.

Association between variants around IRF6 and non-syndromic orofacial cleft in Western Han Chinese.

OBJECTIVES: Considering limitations of previous studies and differences across populations and subtypes, this study aimed to identify new potential SNPs around IRF6 associated with non-syndromic orofacial cleft (NSOC) in Western Han Chinese. MATERIALS AND METHODS: We recruited 376 NSOC case-parent trios, including 125 non-syndromic cleft lip only (NSCLO) trios, 151 non-syndromic cleft lip and palate (NSCLP) trios, and 100 non-syndromic cleft palate only (NSCPO) trios. Twenty-two single-nucleotide polymorphisms (SNPs) were genotyped using MassARRAY method. Hardy-Weinberg equilibrium test, allelic transmission disequilibrium test (TDT) analysis, sliding-window haplotype TDT analysis, and tests for parent-of-origin effect were performed using the PLINK software. Pairwise linkage disequilibrium (LD) was computed using the Haploview program. RESULTS: In TDT analysis, allele A at rs17015217 (p = 0.00011, OR = 0.61 and 95% CI: 0.47-0.78) and allele T at rs12080691 (p = 0.00011, OR = 0.61 and 95% CI: 0.47-0.78) were under-transmitted among NSCLO trios but over-transmitted among NSCPO trios. Haplotypes showing evidence of under-transmission in NSCLO trios were over-transmitted in NSCPO trios. In tests for parent-of-origin effects, T allele at rs12080691 presented paternal under-transmission among NSCLO trios but over-transmission among NSCPO trios. CONCLUSIONS: Allele A at rs17015217 and allele T at rs12080691 are associated with NSCLO and NSCPO with potential to have opposite effects on two subtypes in this sample from Western Han Chinese.

Base-specific mutational intolerance near splice sites clarifies the role of nonessential splice nucleotides.

Variation in RNA splicing (i.e., alternative splicing) plays an important role in many diseases. Variants near 5' and 3' splice sites often affect splicing, but the effects of these variants on splicing and disease have not been fully characterized beyond the two "essential" splice nucleotides flanking each exon. Here we provide quantitative measurements of tolerance to mutational disruptions by position and reference allele-alternative allele combinations. We show that certain reference alleles are particularly sensitive to mutations, regardless of the alternative alleles into which they are mutated. Using public RNA-seq data, we demonstrate that individuals carrying such variants have significantly lower levels of the correctly spliced transcript, compared to individuals without them, and confirm that these specific substitutions are highly enriched for known Mendelian mutations. Our results propose a more refined definition of the "splice region" and offer a new way to prioritize and provide functional interpretation of variants identified in diagnostic sequencing and association studies.

Evolutionary history inferred from the de novo assembly of a nonmodel organism, the blue-eyed black lemur.

Lemurs, the living primates most distantly related to humans, demonstrate incredible diversity in behaviour, life history patterns and adaptive traits. Although many lemur species are endangered within their native Madagascar, there is no high-quality genome assembly from this taxon, limiting population and conservation genetic studies. One critically endangered lemur is the blue-eyed black lemur Eulemur flavifrons. This species is fixed for blue irises, a convergent trait that evolved at least four times in primates and was subject to positive selection in humans, where 5' regulatory variation of OCA2 explains most of the brown/blue eye colour differences. We built a de novo genome assembly for E. flavifrons, providing the most complete lemur genome to date, and a high confidence consensus sequence for close sister species E. macaco, the (brown-eyed) black lemur. From diversity and divergence patterns across the genomes, we estimated a recent split time of the two species (160 Kya) and temporal fluctuations in effective population sizes that accord with known environmental changes. By looking for regions of unusually low diversity, we identified potential signals of directional selection in E. flavifrons at MITF, a melanocyte development gene that regulates OCA2 and has previously been associated with variation in human iris colour, as well as at several other genes involved in melanin biosynthesis in mammals. Our study thus illustrates how whole-genome sequencing of a few individuals can illuminate the demographic and selection history of nonmodel species.

Ultrasound Trigger Ce-Based MOF Nanoenzyme For Efficient Thrombolytic Therapy.

The inflammatory damage caused by thrombus formation and dissolution can increase the risk of thrombotic complications on top of cell death and organ dysfunction caused by thrombus itself. Therefore, a rapid and precise thrombolytic therapy strategy is in urgent need to effectively dissolve thrombus and resist oxidation simultaneously. In this study, Ce-UiO-66, a cerium-based metal-organic framework (Ce-MOF) with reactive oxygen species (ROS) scavenging properties, encapsulated by low-immunogenic mesenchymal stem cell membrane with inflammation-targeting properties, is used to construct a targeted nanomedicine Ce-UiO-CM. Ce-UiO-CM is applied in combination with external ultrasound stimulation for thrombolytic therapy in rat femoral artery. Ce-UiO-66 has abundant Ce (III)/Ce (IV) coupling sites that react with hydrogen peroxide (H2O2) to produce oxygen, exhibiting catalase (CAT) activity. The multi-cavity structure of Ce-UiO-66 can generate electron holes, and its pore channels can act as micro-reactors to further enhance its ROS scavenging capacity. Additionally, the porous structure of Ce-UiO-66 and the oxygen produced by its reaction with H2O2 may enhance the cavitation effects of ultrasound, thereby improving thrombolysis efficacy.

A follicle-stimulating hormone receptor-targeted near-infrared fluorescent probe for tumor-selective imaging and photothermal therapy.

Late detection, peritoneal dissemination, chemoresistance and weak response to targeted therapeutics lead to high mortality in ovarian cancer. More efficient and specific tumor imaging and therapeutic agents are needed to improve the resection rate of surgery and to eliminate residual disease. The expression patterns of follicle-stimulating hormone (FSH) receptor make it a suitable target for ovarian cancer. Here, we report a strategy to develop an organic near-infrared probe for FSH receptor-targeted tumor imaging and photothermal therapy. The FSH-Rh760 probe was conjugated from the Rh760 fluorophore with the FSH ß subunit 33-53 peptide. FSH-Rh760 specifically distinguished peritoneal metastatic ovarian cancerous foci from surrounding normal tissues with a high tumor-to-background ratio. The fluorescence signals in tumors peaked at 2 h and were cleared at 120 h postinjection. FSH-Rh760 treatment rapidly increased the abdomen temperature of mice up to ∼43 °C upon exposure to a near-infrared laser and effectively suppressed peritoneal tumor growth with tumor specificity. No significant systemic toxicities were observed. This study demonstrates the targeting ability and biocompatibility of FSH receptor-targeted theranostics and highlights its potential for clinical application in imaging-guided precision tumor resection and photothermal therapy to eliminate cancer lesions intraoperatively and postoperatively.

Clinical efficacy of acupuncture therapy combined with core muscle exercises in treating patients with chronic nonspecific low back pain: a systematic review and meta-analysis of randomized controlled trials.

Introduction: This meta-analysis aimed to determine the clinical efficacy of acupuncture combined with core muscle exercises on pain and functional status in patients with chronic nonspecific low back pain. Methods: This study followed the Preferred Reporting Items for Systematic Reviews and meta-analysis criteria for systematic reviews and meta-analyses. Randomized controlled trials published till November 2023 were searched in PubMed, Web of Science, Cochrane, Embase, China National Knowledge Infrastructure, Chinese Biomedical Literature, and Wanfang databases. The search strategy was related to disease type, intervention, and control measures and was structured around the search terms "low back pain," "acupuncture therapy," and "exercise." Two reviewers applied inclusion and exclusion criteria. Sensitivity and fixed effects analyses were performed to determine the primary outcomes. Results: We included 11 randomized controlled trials (n = 727) on acupuncture combined with core muscle exercises in patients with chronic nonspecific low back pain. Compared with controls, clinical efficacy was significant, with improvements in pain scores (visual analog pain scale and numerical rating scale) and Oswestry Disability Index in the intervention group. Discussion: Acupuncture therapy combined with core muscle exercises improved pain and functional status in patients with chronic nonspecific low back pain, with favorable clinical outcomes compared with single-core muscle training. Multicenter large-sample trials are required to obtain more reliable conclusions.

The convergent evolution of blue iris pigmentation in primates took distinct molecular paths.

How many distinct molecular paths lead to the same phenotype? One approach to this question has been to examine the genetic basis of convergent traits, which likely evolved repeatedly under a shared selective pressure. We investigated the convergent phenotype of blue iris pigmentation, which has arisen independently in four primate lineages: humans, blue-eyed black lemurs, Japanese macaques, and spider monkeys. Characterizing the phenotype across these species, we found that the variation within the blue-eyed subsets of each species occupies strongly overlapping regions of CIE L*a*b* color space. Yet whereas Japanese macaques and humans display continuous variation, the phenotypes of blue-eyed black lemurs and their sister species (whose irises are brown) occupy more clustered subspaces. Variation in an enhancer of OCA2 is primarily responsible for the phenotypic difference between humans with blue and brown irises. In the orthologous region, we found no variant that distinguishes the two lemur species or associates with quantitative phenotypic variation in Japanese macaques. Given the high similarity between the blue iris phenotypes in these species and that in humans, this finding implies that evolution has used different molecular paths to reach the same end.

The autophagy pathway beyond model organisms: an evolutionary perspective.

In this issue, we answer a frequently asked question regarding the evolution of the macroautophagy/autophagy pathway.

Improving VOC control strategies in industrial parks based on emission behavior, environmental effects, and health risks: A case study through atmospheric measurement and emission inventory.

Industrial parks have a very important impact on regional economic development, but the extremely complex and relatively concentrated volatile organic compound (VOC) emissions from industrial parks also result in it being difficult to control VOCs. In this study, we took a large integrated industrial park in the upper reaches of the Yangtze River as an example, conducted a 1-year monitoring campaign of ambient air VOCs, and established a speciated VOC emission inventory based on the measured chemical profiles of the key industries. The comprehensive control index (CCI) of 125 VOCs was evaluated using the entropy weighting method based on comprehensive consideration of three aspects, namely, emission behavior, environmental effects, and health risks of VOCs, to identify priority VOC species and their key sources for VOC control in industrial parks. The total estimated VOC emissions in the industrial park in 2019 were 6446.96 t. Steel production, sewage treatment, natural gas chemical industry, pharmaceuticals, and industrial boilers were the main sources of VOC emissions. In terms of VOC components, halocarbons, aromatics, and OVOCs were the largest groups of VOCs emitted from the industrial park, accounting for 73.75 % of the total VOC emissions. Using the entropy weighting method, we evaluated the index weights of five parameters: emissions, ozone formation potential, secondary organic aerosol formation potential, hazard quotient, and lifetime cancer risk. Based on the CCI, five control levels for VOC species were further established. The VOC species in Level I and Level II, which contain species such as naphthalene, 2-chlorotoluene, benzene, acrolein, and chloroform, should be considered as extremely important priority control species. These results serve as a reference for the development of precise control strategies for VOCs in industrial parks.

Immunogenic landscape and risk score prediction based on unfolded protein response (UPR)-related molecular subtypes in hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is the most common type of cancer and causes a significant number of cancer-related deaths worldwide. The molecular mechanisms underlying the development of HCC are complex, and the heterogeneity of HCC has led to a lack of effective prognostic indicators and drug targets for clinical treatment of HCC. Previous studies have indicated that the unfolded protein response (UPR), a fundamental pathway for maintaining endoplasmic reticulum homeostasis, is involved in the formation of malignant characteristics such as tumor cell invasiveness and treatment resistance. The aims of our study are to identify new prognostic indicators and provide drug treatment targets for HCC in clinical treatment based on UPR-related genes (URGs). Methods: Gene expression profiles and clinical information were downloaded from the TCGA, ICGC and GEO databases. Consensus cluster analysis was performed to classify the molecular subtypes of URGs in HCC patients. Univariate Cox regression and machine learning LASSO algorithm were used to establish a risk prognosis model. Kaplan-Meier and ROC analyses were used to evaluate the clinical prognosis of URGs. TIMER and XCell algorithms were applied to analyze the relationships between URGs and immune cell infiltration. Real time-PCR was performed to analyze the effect of sorafenib on the expression levels of four URGs. Results: Most URGs were upregulated in HCC samples. According to the expression pattern of URGs, HCC patients were divided into two independent clusters. Cluster 1 had a higher expression level, worse prognosis, and higher expression of immunosuppressive factors than cluster 2. Patients in cluster 1 were more prone to immune escape during immunotherapy, and were more sensitive to chemotherapeutic drugs. Four key UPR genes (ATF4, GOSR2, PDIA6 and SRPRB) were established in the prognostic model and HCC patients with high risk score had a worse clinical prognosis. Additionally, patients with high expression of four URGs are more sensitive to sorafenib. Moreover, ATF4 was upregulated, while GOSR2, PDIA6 and SRPRB were downregulated in sorafenib-treated HCC cells. Conclusion: The UPR-related prognostic signature containing four URGs exhibits high potential application value and performs well in the evaluation of effects of chemotherapy/immunotherapy and clinical prognosis.

Evolutionary diversification of the autophagy-related ubiquitin-like conjugation systems.

Two autophagy-related (ATG) ubiquitin-like conjugation systems, the ATG12 and ATG8 systems, play important roles in macroautophagy. While multiple duplications and losses of the ATG conjugation system proteins are found in different lineages, the extent to which the underlying systems diversified across eukaryotes is not fully understood. Here, in order to understand the evolution of the ATG conjugation systems, we constructed a transcriptome database consisting of 94 eukaryotic species covering major eukaryotic clades and systematically identified ATG conjugation system components. Both ATG10 and the C-terminal glycine of ATG12 are essential for the canonical ubiquitin-like conjugation of ATG12 and ATG5. However, loss of ATG10 or the C-terminal glycine of ATG12 occurred at least 16 times in a wide range of lineages, suggesting that possible covalent-to-non-covalent transition is not limited to the species that we previously reported such as Alveolata and some yeast species. Some species have only the ATG8 system (with conjugation enzymes) or only ATG8 (without conjugation enzymes). More than 10 species have ATG8 homologs without the conserved C-terminal glycine, and Tetrahymena has an ATG8 homolog with a predicted transmembrane domain, which may be able to anchor to the membrane independent of the ATG conjugation systems. We discuss the possibility that the ancestor of the ATG12 and ATG8 systems is more similar to ATG8. Overall, our study offers a whole picture of the evolution and diversity of the ATG conjugation systems among eukaryotes, and provides evidence that functional diversifications of the systems are more common than previously thought.Abbreviations: APEAR: ATG8-PE association region; ATG: autophagy-related; LIR: LC3-interacting region; NEDD8: neural precursor cell expressed, developmentally down-regulated gene 8; PE: phosphatidylethanolamine; SAMP: small archaeal modifier protein; SAR: Stramenopiles, Alveolata, and Rhizaria; SMC: structural maintenance of chromosomes; SUMO: small ubiquitin like modifier; TACK: Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota; UBA: ubiquitin like modifier activating enzyme; UFM: ubiquitin fold modifier; URM: ubiquitin related modifier.

An NIR-II Photothermally Triggered "Oxygen Bomb" for Hypoxic Tumor Programmed Cascade Therapy.

Hypoxia, as a characteristic feature of solid tumors, has a close relationship with tumor resistance to photodynamic therapy (PDT) and chemotherapy. Perfluorocarbon (PFC) is reported to relieve hypoxic in solid tumors by acting as an oxygen carrier via several nanostructures. However, the oxygen delivery process is mostly driven by a concentration gradient, which is uncontrollable. Herein, a photothermally controlled "oxygen bomb" PSPP-Au980 -D is designed by encapsulating a PFC core within a functionalized bilayer polymer shell. Near-infrared second window photothermal agent gold nanorods with excellent photo-to-heat energy-conversion ability are fabricated on the surface of the polymer shell via an innovative modified two-step seedless ex situ growth process to thermally trigger O2  release. Then, a programmed cascade therapy strategy is customized for hypoxic orthotopic pancreatic cancer. First, PSPP-Au980 -D is irradiated by a 980 nm laser to photothermally trigger O2  infusing into the hypoxic tumor microenvironment, which is accompanied by local hyperemia and doxorubicin release. Subsequently, a 680 nm laser is used to generate singlet oxygen in the oxygenated tumor microenvironment for PDT. This choreographed programmed cascade therapy strategy will provide a new route for suppressing hypoxic tumor growth under mild conditions based on controllable and effective oxygen release.