Association between mitochondrial DNA genotype and sperm motility in humans.

The relationship between genetic alterations in mitochondrial DNA (mtDNA) and progressive motility (PR) and rapid progressive motility (grade A) of ejaculated human spermatozoa remains unclear. In this study, we explored the association between human mtDNA genotype and sperm PR and grade A by analyzing mtDNA copy number, loci, haplogroup, rearrangement, deletions, and duplications and sperm motility parameters. Human sperm mtDNA copy number, loci and haplogroups were not associated with human sperm motility PR or A grade. However, the cumulative frequency of human sperm mtDNA rearrangements (including deletions and duplications) in participants with high PR and grade A ratio was higher than in participants with low PR and grade A ratio. Additional studies are needed to understand the relationship between mtDNA genotypes, including deletions and duplications, and human sperm motility.

P-doped spherical hard carbon with high initial coulombic efficiency and enhanced capacity for sodium ion batteries.

Hard carbon (HC) is one of the most promising anode materials for sodium-ion batteries (SIBs) due to its cost-effectiveness and low-voltage plateau capacity. Heteroatom doping is considered as an effective strategy to improve the sodium storage capacity of HC. However, most of the previous heteroatom doping strategies are performed at a relatively low temperature, which could not be utilized to raise the low-voltage plateau capacity. Moreover, extra doping of heteroatoms could create new defects, leading to a low initial coulombic efficiency (ICE). Herein, we propose a repair strategy based on doping a trace amount of P to achieve a high capacity along with a high ICE. By employing the cross-linked interaction between glucose and phytic acid to achieve the in situ P doped spherical hard carbon, the obtained PHC-0.2 possesses a large interlayer space that facilitates Na+ storage and transportation. In addition, doping a suitable amount of P could repair some defects in carbon layers. When used as an anode material for SIBs, the PHC-0.2 exhibits an enhanced reversible capacity of 343 mA h g-1 at 20 mA g-1 with a high ICE of 92%. Full cells consisting of a PHC-0.2 anode and a Na2Fe0.5Mn0.5[Fe(CN)6] cathode exhibited an average potential of 3.1 V with an initial discharge capacity of 255 mA h g-1 and an ICE of 85%. The full cell displays excellent cycling stability with a capacity retention of 80.3% after 170 cycles. This method is simple and low-cost, which can be extended to other energy storage materials.

Extracellular vesicles containing MFGE8 from colorectal cancer facilitate macrophage efferocytosis.

BACKGROUND: Colorectal cancer (CRC) commonly exhibits tolerance to cisplatin treatment, but the underlying mechanisms remain unclear. Within the tumor microenvironment, macrophages play a role in resisting the cytotoxic effects of chemotherapy by engaging in efferocytosis to clear apoptotic cells induced by chemotherapeutic agents. The involvement of extracellular vesicles (EVs), an intercellular communicator within the tumor microenvironment, in regulating the efferocytosis for the promotion of drug resistance has not been thoroughly investigated. METHODS: We constructed GFP fluorescent-expressing CRC cell lines (including GFP-CT26 and GFP-MC38) to detect macrophage efferocytosis through flow cytometric analysis. We isolated and purified CRC-secreted EVs using a multi-step ultracentrifugation method and identified them through electron microscopy and nanoflow cytometry. Proteomic analysis was conducted to identify the protein molecules carried by CRC-EVs. MFGE8 knockout CRC cell lines were constructed using CRISPR-Cas9, and their effects were validated through in vitro and in vivo experiments using Western blotting, immunofluorescence, and flow cytometric analysis, confirming that these EVs activate the macrophage αvß3-Src-FAK-STAT3 signaling pathway, thereby promoting efferocytosis. RESULTS: In this study, we found that CRC-derived EVs (CRC-EVs) enhanced macrophage efferocytosis of cisplatin-induced apoptotic CRC cells. Analysis of The Cancer Genome Atlas (TCGA) database revealed a high expression of the efferocytosis-associated gene MFGE8 in CRC patients, suggesting a poorer prognosis. Additionally, mass spectrometry-based proteomic analysis identified a high abundance of MFGE8 protein in CRC-EVs. Utilizing CRISPR-Cas9 gene edition system, we generated MFGE8-knockout CRC cells, demonstrating that their EVs fail to upregulate macrophage efferocytosis in vitro and in vivo. Furthermore, we demonstrated that MFGE8 in CRC-EVs stimulated macrophage efferocytosis by increasing the expression of αvß3 on the cell surface, thereby activating the intracellular Src-FAK-STAT3 signaling pathway. CONCLUSIONS: Therefore, this study highlighted a mechanism in CRC-EVs carrying MFGE8 activated the macrophage efferocytosis. This activation promoted the clearance of cisplatin-induced apoptotic CRC cells, contributing to CRC resistance against cisplatin. These findings provide novel insights into the potential synergistic application of chemotherapy drugs, EVs inhibitors, and efferocytosis antagonists for CRC treatment.

Recovering carbon fibers from waste CFRPs via pyrolysis-oxidation method: Implications for reuse in remanufactured materials.

Carbon fiber-reinforced polymer composites (CFRPs) have gained widespread usage due to their promising physiochemical properties, while this causes large amounts of waste CFRPs worldwide. In this study, carbon fibers were successfully recovered from waste CFRPs through the pyrolysis-oxidation method, and the recovered fibers were reused in remanufacturing the secondary generation CFRPs. Moreover, the individual and interactive effects of pyrolysis-oxidation recovering parameters on the mechanical strength of the resulting remanufactured CFRPs (reCFRPs) were investigated. The recovered carbon fibers displayed surface chemical structures similar to virgin fibers but with high contents of oxygen-containing bonds. The tensile strength retention (TSR) of the reCFRPs was primarily influenced by oxidation temperature. Notably, a higher oxidation temperature, especially exceeding 560 °C, amplified the impact of oxidation duration on the TSR value. Similarly, concerning interlaminar shear strength retention (ISSR), the oxidation stage had a more substantial effect compared to the pyrolysis stage. As the oxidation temperature increased from 500 °C to 600 °C, the ISSR value initially increased and then decreased, irrespective of variations in pyrolysis parameters. Additionally, through integrating the response surface methodology (RSM) analysis and multi-island genetic algorithm (MIGA) global optimization, three recovery strategies, along with the corresponding processing parameters, were proposed to meet diverse requirements. The conclusions could provide valuable insights for optimizing the recovery and reuse of carbon fibers from waste CFRPs.

Emergence and genomic chion of Proteus mirabilis harboring blaNDM-1 in Korean companion dogs.

Proteus mirabilis is a commensal bacterium dwelling in the gastrointestinal (GI) tract of humans and animals. Although New Delhi metallo-ß-lactamase 1 (NDM-1) producing P. mirabilis is emerging as a threat, its epidemiology in our society remains largely unknown. LHPm1, the first P. mirabilis isolate harboring NDM-1, was detected from a companion dog that resides with a human owner. The whole-genome study revealed 20 different antimicrobial resistance (AMR) genes against various classes of antimicrobial agents, which corresponded to the MIC results. Genomic regions, including MDR genes, were identified with multiple variations and visualized in a comparative manner. In the whole-genome epidemiological analysis, multiple phylogroups were identified, revealing the genetic relationship of LHPm1 with other P. mirabilis strains carrying various AMR genes. These genetic findings offer comprehensive insights into NDM-1-producing P. mirabilis, underscoring the need for urgent control measures and surveillance programs using a "one health approach".

Ultrasound-augmented cancer immunotherapy.

Cancer is a growing worldwide health problem with the most broadly studied treatments, in which immunotherapy has made notable advancements in recent years. However, innumerable patients have presented a poor response to immunotherapy and simultaneously experienced immune-related adverse events, with failed therapeutic results and increased mortality rates. Consequently, it is crucial to develop alternate tactics to boost therapeutic effects without producing negative side effects. Ultrasound is considered to possess significant therapeutic potential in the antitumor field because of its inherent characteristics, including cavitation, pyrolysis, and sonoporation. Herein, this timely review presents the comprehensive and systematic research progress of ultrasound-enhanced cancer immunotherapy, focusing on the various ultrasound-related mechanisms and strategies. Moreover, this review summarizes the design and application of current sonosensitizers based on sonodynamic therapy, with an attempt to provide guidance on new directions for future cancer therapy.

The extrachromosomal circular DNA atlas of aged and young mouse brains.

Extrachromosomal circular DNA (eccDNA) refers to a distinct class of circular DNA molecules that exist independently from linear chromosomal DNA. Extensive evidence has firmly established the significant involvement of eccDNA in cancer initiation, progression, and evolutionary processes. However, the relationship between eccDNA and brain aging remains elusive. Here, we employed extrachromosomal circular DNA sequencing (Circle-seq) to generate a comprehensive dataset of eccDNA from six brain structures of both young and naturally-aged mice, including the olfactory bulb, medial prefrontal cortex, nucleus accumbens, caudate putamen, hippocampus, and cerebellum. Furthermore, through database annotation, we characterized the properties of mouse brain eccDNA, thereby gaining insights into the potential functions of eccDNA in the mouse brain. In conclusion, our study addresses a previously unexplored area by providing a comprehensive molecular characterization of eccDNA in brain tissues. The data presented in the study can be used as a fundamental resource to associate the molecular phenotypes of eccDNA with brain aging and gain deep insights into the biological role of eccDNA in mammalian brain aging.

Circle-seq based method for eccDNA synthesis and its application as a canonical promoter independent vector for robust microRNA overexpression.

Extrachromosomal circular DNA (eccDNA) has recently gained increasing attention due to its significant role in cancer and other pathophysiologic states. The majority of circular DNAs detected by Circle-seq are small-size eccDNAs with enigmatic functions. One major technical hurdle is to synthesize eccDNA for functional identification. Here, we describe CAES (Circle-seq based Artificial EccDNA Synthesis), a promising and reliable method for artificial eccDNA synthesis. Eight eccDNAs carrying different microRNA genes (eccMIR) found in gastric cancer tissues, ranging from 329 bp to 2189 bp in size, were created utilizing the CAES method. Exonuclease V and single restriction-endonuclease digestion identified the circular structure of synthetic eccDNAs. The DNA circularization efficiency afforded by CAES ranged from 15.6% to 31.1%, which was negatively correlated with the eccDNA length. In addition, we demonstrated that CAES-synthesized eccMIRs can express both miRNA-3p and - 5p molecules efficiently independent of a canonical promoter in human cell lines. Further assays proved that these eccMIRs were functional as they were able to repress the luciferase gene containing a miRNA-target sequence in the 3'UTR as well as the endogenous mRNA targets. Finally, kinetics study revealed that eccDNA exhibited a decay rate similar to the standard plasmids and linear DNA in cultured cells. Together, this study offers a rapid and convenient method for Circle-seq users to synthesize artificial eccDNAs. It also demonstrates the promising potential of eccMIR as a bacterial DNA-free vector for safe and robust miRNA overexpression in both basic research and therapeutic applications.

Conjugated Network Supporting Highly Surface-Exposed Ru Site-Based Artificial Antioxidase for Efficiently Modulating Microenvironment and Alleviating Solar Dermatitis.

Solar dermatitis, a form of acute radiation burn that affects the skin, results from overexposure to ultraviolet B (UVB) radiation in strong sunlight. Cell damage caused by the accumulation of reactive oxygen species (ROS) produced by UVB radiation plays an important role in UVB-induced inflammation in the skin. Here, for efficiently scavenging excess ROS, modulating the microenvironment, and alleviating solar dermatitis, a π-conjugated network polyphthalocyanine supporting a highly surface-exposed Ru active site-based artificial antioxidase (HSE-PPcRu) is designed and fabricated with excellent ROS-scavenging, antioxidant, and anti-inflammatory capabilities. In photodamaged human keratinocyte cells, HSE-PPcRu could modulate mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B signaling pathways, prevent DNA damage, suppress apoptosis, inhibit pro-inflammatory cytokine secretion, and alleviate cell damage. In vivo animal experiments reveal the higher antioxidant and anti-inflammatory efficacies of HSE-PPcRu by reversing the activation of p38 and c-Jun N-terminal kinase, inhibiting expression of cyclooxygenase-2, interleukin-6, interleukin-8, and tumor necrosis factor-α. This work not only provides an idea for alleviating solar dermatitis via catalytically scavenging ROS and modulating the microenvironment but also offers a strategy to design an intelligent conjugated network-based artificial antioxidase with a highly surface-exposed active site.

Enantioselective Total Synthesis of (-)-Daphenylline.

A concise enantioselective total synthesis of (-)-daphenylline, a hexacyclic Daphniphyllum alkaloid with a unique benzene ring, was achieved in 14 steps. The synthesis commences with two chiral stereocenters, C2 and C18, readily installed via Carreira's Ir/amine dual-catalyzed allylation. The allylic bridgehead amine 6 was rapidly prepared through Wickens' photoredox-catalyzed hydrocarboxylation of olefin and CuBr2-catalyzed α-amination of ketone. The tetracycle 4 was formed via Pd-catalyzed reductive Heck reaction or, more concisely, by Krische's Rh-catalyzed reductive 1,6-enyne cyclization. In this synthesis, newly reported Wickens' photoredox-catalyzed hydrocarboxylation was used twice, and Friedel-Crafts acylation thrice.

l-Theanine delays d-galactose-induced senescence by regulating the cell cycle and inhibiting apoptosis in rat intestinal cells.

BACKGROUND: Intestinal senescence is associated with several aging-related diseases. l-Theanine (LTA) has demonstrated strong potential as an antioxidant and antisenescence agent. This study investigated the regulatory effect of LTA on cellular senescence using an in vitro model of d-galactose (D-Gal)-induced senescence in the rat epithelial cell line, intestinal epithelioid cell-6 (IEC-6). RESULTS: Treatment of IEC-6 cells with 40 mg/mL D-Gal for 48 h resulted in the successful development of the senescent cell model. Compared with D-Gal alone, both LTA preventive and delayed intervention increased cell viability and the ratio of JC-1 monomers to aggregates, increased the antioxidant capacity, and decreased the advanced glycation end product (AGE) levels and the overall number of senescent cells. Preventive and delayed intervention with 1000 µM LTA alleviated the D-Gal-induced cell cycle arrest by regulating p38, p53, CDK4, and CDK6 expression at the mRNA and protein levels, and further induced CycD1 proteins. Moreover, LTA preventive intervention reduced apoptosis to a greater degree than delayed intervention by upregulating the expression of the receptors of AGEs, Bax, Bcl-2, and NF-κB at the mRNA and protein levels. CONCLUSION: Our findings indicate that LTA intervention could attenuate senescence in IEC-6 cells by regulating the cell cycle and inhibiting apoptosis. © 2023 Society of Chemical Industry.

Pre-Oxidation Strategy Transforming Waste Foam to Hard Carbon Anodes for Boosting Sodium Storage Performance.

Large reserves, high capacity, and low cost are the core competitiveness of disordered carbon materials as excellent anode materials for sodium-ion batteries (SIBs). And the existence and improper treatment of a large number of organic solid wastes will aggravate the burden on the environment, therefore, it is significant to transform wastes into carbon-based materials for sustainable energy utilization. Herein, a kind of hard carbon materials are reported with waste biomass-foam as the precursor, which can improve the sodium storage performance through pre-oxidation strategy. The introduction of oxygen-containing groups can promote structural cross-linking, and inhibit the melting and rearrangement of carbon structure during high-temperature carbonization that produces a disordered structure with a suitable degree of graphitization. Moreover, the micropore structure are also regulated during the high-temperature carbonization process, which is conducive to the storage of sodium ions in the low-voltage plateau region. The optimized sample as an electrode material exhibits excellent reversible specific capacity (308.0 mAh g-1) and initial Coulombic efficiency (ICE, 90.1%). In addition, a full cell with the waste foam-derived hard carbon anode and a Na3V2(PO4)3 cathode is constructed with high ICE and energy density. This work provides an effective strategy to conversion the waste to high-value hard carbon anode for sodium-ion batteries.

Konjac flour-mediated gut microbiota alleviates insulin resistance and improves placental angiogenesis of obese sows.

Our previous study revealed that dietary konjac flour (KF) could remodel gut microbiota and improve reproductive performance of sows, but its underlying mechanisms remain unclear. This experiment aimed to investigate how dietary KF improves reproductive performance of obese sows. Here, 60 sows were assigned into three groups according to their backfat thickness: normal backfat sows fed with control diet (CON-N), high backfat sows fed with control diet (CON-H) and high backfat sows fed with KF inclusion diet (KF-H). The characteristics of sows and piglets were recorded. Next, fecal microbiota transplantation (FMT) was performed on female mice, followed by recording the characteristics of female mice. The results showed that compared with CON-H group, KF-H group showed downtrend in stillbirth rate (P = 0.07), an increase in placental efficiency (P < 0.01) and average piglet weight (P < 0.01); coupled with a decrease in the values of homeostasis model assessment-insulin resistance (P < 0.01); as well as an increase in placental vascular density and protein expression of angiogenesis markers (P < 0.01). As expected, sows fed KF diets had improved abundance and diversity of gut microbiota. More importantly, compared with CON-H(FMT) group, KF-H(FMT) group showed improvement in reproductive performance and insulin sensitivity (P < 0.05), as well as an increase in placental labyrinth zone and protein expression of angiogenesis markers (P < 0.05). Furthermore, we found a content increase (P < 0.05) of SCFAs in both KF-H group sow and KF-H (FMT) group mice. Overall, KF supplementation could alleviate insulin resistance, promote placental angiogenesis, and ultimately improve the reproductive performance of sows via gut microbiota remodeling.

Sonneralignan A, a new lignan from the fruit of mangrove Sonneratia apetala.

A new lignan, sonneralignan A (1), along with two known lignan compounds, (+)-lariciresinol-9-O-ß-D-glucopyranoside (2) and (-)isolariciresinol-9-O-ß-D-glucopyranoside (3) were isolated from the n-butanol extract of the mangrove Sonneratia apetala fruit. The structures of the compounds were elucidated on the basis of extensive spectral analysis. The evaluation of activity showed that compound 1 exhibited significant anti-aging activity, which extended the mean lifespan of Caenorhabditis elegans by up to 19.13% (p < 0.05) and 55.29% (p < 0.01) under normal and heat stress cultivation conditions, respectively. Molecular docking studies showed that compound 1 was bound to the DNA binding domain of DAF-16 and promoted the conformation of DAF-16, thus strengthening the interaction between the DAF-16 and related DNA. TRP-252, SER-250 and SER-249 of the binding region might be the key amino residues during the interaction.

Dissecting molecular mechanisms underlying ferroptosis in human umbilical cord mesenchymal stem cells: Role of cystathionine γ-lyase/hydrogen sulfide pathway.

BACKGROUND: Ferroptosis can induce low retention and engraftment after mesenchymal stem cell (MSC) delivery, which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension (PAH) therapy. Interestingly, the cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway may contribute to mediating ferroptosis. However, the influence of the CSE/H2S pathway on ferroptosis in human umbilical cord MSCs (HUCMSCs) remains unclear. AIM: To clarify whether the effect of HUCMSCs on vascular remodelling in PAH mice is affected by CSE/H2S pathway-mediated ferroptosis, and to investigate the functions of the CSE/H2S pathway in ferroptosis in HUCMSCs and the underlying mechanisms. METHODS: Erastin and ferrostatin-1 (Fer-1) were used to induce and inhibit ferroptosis, respectively. HUCMSCs were transfected with a vector to overexpress or inhibit expression of CSE. A PAH mouse model was established using 4-wk-old male BALB/c nude mice under hypoxic conditions, and pulmonary pressure and vascular remodelling were measured. The survival of HUCMSCs after delivery was observed by in vivo bioluminescence imaging. Cell viability, iron accumulation, reactive oxygen species production, cystine uptake, and lipid peroxidation in HUCMSCs were tested. Ferroptosis-related proteins and S-sulfhydrated Kelch-like ECH-associating protein 1 (Keap1) were detected by western blot analysis. RESULTS: In vivo, CSE overexpression improved cell survival after erastin-treated HUCMSC delivery in mice with hypoxia-induced PAH. In vitro, CSE overexpression improved H2S production and ferroptosis-related indexes, such as cell viability, iron level, reactive oxygen species production, cystine uptake, lipid peroxidation, mitochondrial membrane density, and ferroptosis-related protein expression, in erastin-treated HUCMSCs. In contrast, in vivo, CSE inhibition decreased cell survival after Fer-1-treated HUCMSC delivery and aggravated vascular remodelling in PAH mice. In vitro, CSE inhibition decreased H2S levels and restored ferroptosis in Fer-1-treated HUCMSCs. Interestingly, upregulation of the CSE/H2S pathway induced Keap1 S-sulfhydration, which contributed to the inhibition of ferroptosis. CONCLUSION: Regulation of the CSE/H2S pathway in HUCMSCs contributes to the inhibition of ferroptosis and improves the suppressive effect on vascular remodelling in mice with hypoxia-induced PAH. Moreover, the protective effect of the CSE/H2S pathway against ferroptosis in HUCMSCs is mediated via S-sulfhydrated Keap1/nuclear factor erythroid 2-related factor 2 signalling. The present study may provide a novel therapeutic avenue for improving the protective capacity of transplanted MSCs in PAH.

Integrated genomic analysis of antibiotic resistance and virulence determinants in invasive strains of Streptococcus pneumoniae.

Introduction: Streptococcus pneumoniae is an important human pathogen that may cause severe invasive pneumococcal diseases (IPDs) in young children and the elderly. A comprehensive comparative whole-genome analysis of invasive and non-invasive serotype strains offers great insights that are applicable to vaccine development and disease control. Methods: In this study, 58 invasive (strains isolated from sterile sites) and 71 non-invasive (serotypes that have not been identified as invasive in our study) pneumococcal isolates were identified among the 756 pneumococcal isolates obtained from seven hospitals in Zhejiang, China (2010-2022). Serotyping, antimicrobial resistance tests, and genomic analyses were conducted to characterize these strains. Results and discussion: The three most invasive serotypes were 23F, 14, and 6B. The invasive pneumococcal isolates' respective resistance rates against penicillin, ceftriaxone, tetracycline, and erythromycin were 34.5%, 15.5%, 98.3%, and 94.7%. Whole-genome sequencing indicated that the predominant invasive clonal complexes were CC271, CC876, and CC81. The high rate of penicillin non-susceptible Streptococcus pneumoniae (PNSP) is related to the clonal distribution of resistance-conferring penicillin-binding proteins (PBP). Interestingly, we found a negative correlation between invasiveness and resistance in the invasive pneumococcal serotype strains, which might be due to the proclivity of certain serotypes to retain their ß-lactam resistance. Moreover, the mutually exclusive nature of zmpC and rrgC+srtBCD suggests their intricate and potentially redundant roles in promoting the development of IPD. These findings reveal significant implications for pneumococcal vaccine development in China, potentially informing treatment strategies and measures to mitigate disease transmission.

Limited protection of pneumococcal vaccines against emergent Streptococcus pneumoniae serotype 14/ST876 strains.

PURPOSE: Streptococcus pneumoniae (Spn) is a major cause of child death. We investigated the epidemiology of S. pneumoniae in a pediatric fever clinic and explored the genomics basis of the limited vaccine response of serotype 14 strains worldwide. METHODS: Febrile disease and pneumonia were diagnosed following criteria from the WHO at the end of 2019 at a tertiary children's hospital. Spn was isolated by culture from nasopharyngeal (NP) swabs. The density was determined by lytA-base qPCR. Isolates were serotyped by Quellung and underwent antimicrobial susceptibility testing. Whole-genome sequencing was employed for molecular serotyping, MLST, antibiotic gene determination, SNP calling, recombination prediction, and phylogenetic analysis. RESULTS: The presence of pneumococcus in the nasopharynx (87.5%, 7/8, p = 0.0227) and a high carriage (100%, 7/7, p = 0.0123) were significantly associated with pneumonia development. Living with siblings (73.7%, 14/19, p = 0.0125) and non-vaccination (56.0%, 28/50, p = 0.0377) contributed significantly to the Spn carriage. Serotype 14 was the most prevalent strain (16.67%, 5/30). The genome analysis of 1497 serotype 14 strains indicated S14/ST876 strains were only prevalent in China, presented limited vaccine responses with higher recombination activities within its cps locus, and unique variation patterns in the genes wzg and lrp. CONCLUSION: With the lifting of the one-child policy, it will be crucial for families with multiple children to get PCV vaccinations in China. Due to the highly variant cps locus and distinctive variation patterns in capsule shedding and binding proteins genes, the prevalent S14/ST876 strains have shown poor response to current vaccines. It is necessary to continue monitoring the molecular epidemiology of this vaccine escape clone.

Plasma extrachromosomal circular DNA is a pathophysiological hallmark of short-term intensive insulin therapy for type 2 diabetes.

BACKGROUND: Extrachromosomal circular DNA (eccDNA) has emerged as a promising biomarker for disease diagnosis and prognosis prediction. However, its role in type 2 diabetes remains unexplored. OBJECTIVE: To investigate the characteristics and dynamics of circulating eccDNAs in newly diagnosed type 2 diabetes mellitus (T2DM) patients undergoing short-term intensive insulin therapy (SIIT), a highly effective treatment for inducing long-term glycemic remission. METHODS: We conducted Circle-Seq analysis on plasma samples from 35 T2DM patients at three time points: pre-SIIT, post-SIIT, and 1-year post-SIIT. Our analysis encompassed the characterization of eccDNA features, including GC content, eccDNA length distribution, genomic distribution, and the genes in eccDNAs. RESULTS: Following SIIT, we observed an increase in plasma eccDNA load, suggesting metabolic alterations during therapy. Notably, a correlation was identified between eccDNA profiles and glycemia in T2DM, both quantitatively and genetically. Our analysis also revealed the frequent presence of metabolism-related genes within T2DM plasma eccDNAs, some of which spanned gene exons and/or fractions. CONCLUSION: This study represents the first report of cell-free eccDNA in T2DM and underscores a compelling association between cell-free eccDNA and profound glycemic changes. These findings highlight the potential of eccDNAs as crucial players in the context of T2DM and glycemic control.