Altered ocular surface microbiota in obesity: a case-control study.

Purpose: This study aimed to investigate the composition of ocular surface microbiota in patients with obesity. Methods: This case-control study, spanning from November 2020 to March 2021 at Henan Provincial People's Hospital, involved 35 patients with obesity and an equivalent number of age and gender-matched healthy controls. By employing 16S rRNA sequencing, this study analyzed the differences in ocular surface microbiota between the two groups. The functional prediction analysis of the ocular surface microbiota was conducted using PICRUSt2. Results: The alpha diversity showed no notable differences in the richness or evenness of the ocular surface microbiota when comparing patients with obesity to healthy controls (Shannon index, P=0.1003). However, beta diversity highlighted significant variances in the microbiota composition of these two groups (ANOSIM, P=0.005). LEfSe analysis revealed that the relative abundances of Delftia, Cutibacterium, Aquabacterium, Acidovorax, Caulobacteraceae unclassified, Comamonas and Porphyromonas in patients with obesity were significantly increased (P<0.05). Predictive analysis using PICRUSt2 highlighted a significant enhancement in certain metabolic pathways in patients with obesity, notably xenobiotics metabolism via cytochrome P450 (CYP450), lipid metabolism, and the oligomerization domain (NOD)-like receptor signaling pathway (P<0.05). Conclusions: Patients with obesity exhibit a distinct ocular surface core microbiome. The observed variations in this microbiome may correlate with increased activity in CYP450, changes in lipid metabolism, and alterations in NOD-like receptor signaling pathways.

NEDD4 lactylation promotes APAP induced liver injury through Caspase11 dependent non-canonical pyroptosis.

Caspase-11 detection of intracellular lipopolysaccharide mediates non-canonical pyroptosis, which could result in inflammatory damage and organ lesions in various diseases such as sepsis. Our research found that lactate from the microenvironment of acetaminophen-induced acute liver injury increased Caspase-11 levels, enhanced gasdermin D activation and accelerated macrophage pyroptosis, which lead to exacerbation of liver injury. Further experiments unveiled that lactate inhibits Caspase-11 ubiquitination by reducing its binding to NEDD4, a negative regulator of Caspase-11. We also identified that lactates regulated NEDD4 K33 lactylation, which inhibits protein interactions between Caspase-11 and NEDD4. Moreover, restraining lactylation reduces non-canonical pyroptosis in macrophages and ameliorates liver injury. Our work links lactate to the exquisite regulation of the non-canonical inflammasome, and provides a basis for targeting lactylation signaling to combat Caspase-11-mediated non-canonical pyroptosis and acetaminophen-induced liver injury.

Defense Regulatory Network Associated with circRNA in Rice in Response to Brown Planthopper Infestation.

The brown planthopper (BPH), Nilaparvata lugens (Stål), a rice-specific pest, has risen to the top of the list of significant pathogens and insects in recent years. Host plant-mediated resistance is an efficient strategy for BPH control. Nonetheless, BPH resistance in rice cultivars has succumbed to the emergence of distinct virulent BPH populations. Circular RNAs (circRNAs) play a pivotal role in regulating plant-environment interactions; however, the mechanisms underlying their insect-resistant functions remain largely unexplored. In this study, we conducted an extensive genome-wide analysis using high-throughput sequencing to explore the response of rice circRNAs to BPH infestations. We identified a total of 186 circRNAs in IR56 rice across two distinct virulence groups: IR-IR56-BPH (referring to IR rice infested by IR56-BPH) and IR-TN1-BPH, along with a control group (IR-CK) without BPH infestation. Among them, 39 circRNAs were upregulated, and 43 circRNAs were downregulated in the comparison between IR-IR56-BPH and IR-CK. Furthermore, in comparison with IR-CK, 42 circRNAs exhibited upregulation in IR-TN1-BPH, while 42 circRNAs showed downregulation. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the targets of differentially expressed circRNAs were considerably enriched in a multitude of biological processes closely linked to the response to BPH infestations. Furthermore, we assessed a total of 20 randomly selected circRNAs along with their corresponding expression levels. Moreover, we validated the regulatory impact of circRNAs on miRNAs and mRNAs. These findings have led us to construct a conceptual model that circRNA is associated with the defense regulatory network in rice, which is likely facilitated by the mediation of their parental genes and competing endogenous RNA (ceRNA) networks. This model contributes to the understanding of several extensively studied processes in rice-BPH interactions.

Mechanical strength changes of combustible municipal solid waste components during their early pyrolysis stage and mechanism analysis.

Implementation of municipal solid waste (MSW) source segregation leads to a more convenient recycle of combustible MSW components. Textiles, plastics and papers are commonly available combustible components in MSW. Their shredding is conducive to resources recovery. But these components usually have high tensile strengths and are difficult to shred. To understand their mechanical strength changes in their early pyrolysis stage will help to address this problem. In this study, a universal electronic testing machine was used to determine the breaking strengths of the materials including cotton towel, polyethylene glycol terephthalate (PET), ivory board (IB), kraft paper (KP) and wool scarf in the temperature range of 30-250°C under N2 atmosphere, and the mechanisms of their strength changes were explored. The reaction force field molecular dynamics (ReaxFF-MD) simulation was used to explain the decomposition behaviours of different sugar groups of hemicellulose in cotton and paper and the change of van der Waals energy of wool during their early pyrolysis stages. The results showed that breaking strengths of all the combustible MSW components reduced as the temperature increased. The breaking strength of PET was found to have the highest descent rate with increasing temperature, then the descent rates of wool and cotton came as the second and third, respectively. Compared with cotton, the breaking strengths of KP and IB decreased more slowly. As the temperature increased, the breaking strength of cotton reduced mainly due to the decomposition of the glucuronic acid in hemicellulose, and the reduction was characterized by CO2 release. The breaking strength reduction of PET was caused by its molecular chain being relaxed. The breaking strength reduction of wool was firstly caused by the decrease in the van der Waals energy between its molecules, and then caused by molecular chain breaking. In addition, in order to understand the influence of material size on the breaking strength change during thermal treatment, the breaking strengths of cotton yarn bundles were correlated with their yarn number and temperature. This study lays the foundation for understanding changes in mechanical strengths of combustible MSW components during their early pyrolysis stage.

Supramolecular interactions between functional saccharide-based ionic liquids and cellulose macromolecules.

Interactions between polysaccharides and ionic liquids (ILs) at the molecular level are essential to elucidate the dissolution and/or plasticization mechanism of polysaccharides. Herein, saccharide-based ILs (SILs) were synthesized, and cellulose membrane was soaked in different SILs to evaluate the interactions between SILs and cellulose macromolecules. The relevant results showed that the addition of SILs into cellulose can effectively reduce the intra- and/or inter-molecular hydrogen bonds of polysaccharides. Glucose-based IL showed the intensest supramolecular interactions with cellulose macromolecules compared to sucrose- and raffinose-based ILs. Two-dimensional correlation and perturbation-correlation moving window Fourier transform infrared techniques were for the first time used to reveal the dynamic variation of the supramolecular interactions between SILs and cellulose macromolecules. Except for the typical HO⋯H interactions of cellulose itself, stronger -Cl⋯HO hydrogen bonding interactions were detected in the specimen of SILs-modified cellulose membranes. Supramolecular interactions of -Cl⋯H, HO⋯H, C-Cl⋯H, and -C=O⋯H between SILs and cellulose macromolecules sequentially responded to the stimuli of temperature. This work provides a new perspective to understanding the interaction mechanism between polysaccharides and ILs, and an avenue to develop the next-generation ILs for dissolving or thermoplasticizing polysaccharide materials.

Interplay of Systemic Immune-Inflammation Index and Serum Klotho Levels: Unveiling a New Dimension in Rheumatoid Arthritis Pathology.

Aim: The association between the systemic immune-inflammation index (SII) and serum Klotho concentrations (pg/ml) in patients with rheumatoid arthritis (RA) has not been elucidated. The purpose of this study was to clarify the relationship between the SII and serum Klotho concentrations in RA patients. Methods: All data come from the National Health and Nutrition Examination Survey (NHANES) database in the United States, which included 982 RA patients (age range: 40 to 79 years). The measurement data of the SII and serum Klotho are all from the NHANES mobile examination centre. We constructed a multivariate linear regression model to evaluate the association between the SII and serum Klotho levels in RA patients and conducted a subgroup analysis to test the stability of the statistical results. Results: Multivariate linear regression results indicated a negative linear relationship between the SII and serum Klotho concentrations in RA patients (ß = -6.33, 95% CI [confidence interval]: -10.15 to -2.53). Compared to the quartile 1 group, the quartile 4 group was associated with significantly lower (P<0.001) serum Klotho concentrations (ß = -120.93, 95% CI: -174.84 to -67.02). Compared with the quartile 1 group, with the increase in the SII, the ß value showed a decreasing trend (P trend < 0.001). The subgroup analysis showed that none of the covariates affected the stability of these results (all P for interaction ≥ 0.05). Conclusion: There is a significant negative linear association between the SII and serum Klotho concentrations in RA patients. The SII can serve as a predictive indicator of serum Klotho concentrations in RA patients, and Klotho may be a potential anti-inflammatory target for RA treatment.

Photomechaelectric Nanogenerators with Different Photoisomers and Dipole Units for Harvesting UV Light Energy.

To date, transforming environmental energy into electricity through a non-mechanical way is challenging. Herein, a series of photomechaelectric (PME) polyurethanes containing azobenzene-based photoisomer units and ionic liquid-based dipole units are synthesized, and corresponding PME nanogenerators (PME-NGs) to harvest electricity are fabricated. The dependence of the output performance of PME-NGs on the structure of the polyurethane is evaluated. The results show that the UV light energy can directly transduce into alternating-current (AC) electricity by PME-NGs via a non-mechanical way. The optimal open-circuit voltage and short-circuit current of PME-NGs under UV illumination reach 17.4 V and 696 µA, respectively. After rectification, the AC electricity can be further transformed into direct-current (DC) electricity and stored in a capacitor to serve as a power system to actuate typical microelectronics. The output performance of PME-NGs is closely related to the hard segment content of the PME polyurethane and the radius of counter anions in the dipole units. Kelvin probe force microscopy is used to confirm the existence of the PME effect and the detailed mechanism about the generation of AC electricity in PME-NGs is proposed, referring to the back and forth drift of induced electrons on the two electrodes in contact with the PME polyurethanes.

Co-registration of OPM-MCG signals with CT using optical scanning.

Magnetocardiography (MCG) can be used to noninvasively measure the electrophysiological activity of myocardial cells. The high spatial resolution of magnetic source localization can precisely determine the location of cardiomyopathy, which is of great significance for the diagnosis and treatment of cardiovascular disease. To perform magnetic source localization, MCG data must be co-registered with anatomical images. We propose a co-registration method that can be applied to OPM-MCG systems. In this method, the sensor array and the trunk of the subject are scanned using structured light-scanning technology, and the scan results are registered with the reconstructed structure using computed tomography (CT). This can increase the number of effective cloud points acquired and reduce the interference from respiratory motion. The scanning bed of the OPM-MCG system was modified to be consistent with the CT device, ensuring that the state of the body remains consistent between the cardiac magnetometry measurements and CT scans.

Cyclosporin A-mediated translocation of HuR improves MTX-induced cognitive impairment in a mouse model via NCOA4-mediated ferritinophagy.

Chemotherapy-induced cognitive impairment (CICI) is a subject that requires critical solutions in neuroscience and oncology. However, its potential mechanism of action remains ambiguous. The aim of this study was to investigate the vital role of HuR in the neuroprotection of cyclosporin A (CsA) during methotrexate (MTX)-induced cognitive impairment. A series of Hu-antigen R (HuR) gain and loss experiments were used to examine cyclosporin A (CsA)-mediated translocation of HuR's ability to improve MTX-induced cognitive impairment through NCOA4-mediated ferritinophagy in vitro and in vivo. Obtained results show that the administration of CsA alleviated MTX-induced cognitive impairment in mice. The presence of MTX promoted the shuttling of HuR from the cytoplasm to the nucleus, whereas treatment with CsA increased cytoplasmic HuR expression levels and the levels of ferritinophagy-related proteins, such as NCOA4 and LC3II, compared to the MTX group. However, applying KH-3, an inhibitor of HuR, reversed CsA's impact on the expression of ferritinophagy-related proteins in the hippocampus and in vitro. Also, treatment with CsA attenuated microglial activation by altering Iba-1 expression and decreased TNF-α and IL-1ß levels in mice hippocampi. Moreover, KH-3 neutralized CsA's effects on the expression of both Iba-1 and HuR in vivo and in vitro. In summary, CsA was confirmed to have a neuroprotective role in CICI. Its possible underlying mechanisms may be involved in the translocation of HuR. Mediating the translocation of HuR during CICI could mitigate neruoinflammation and neuronal apoptosis via NCOA4-mediated ferritinophagy and, thus, alleviate cognitive impairment in mice with CICI.

Intra-arterial lidocaine therapy via the middle meningeal artery for migraine headache: Theory, current practice and future directions.

Recent developments in neurointerventional research have seen the emergence of the middle meningeal artery (MMA) as an effective conduit for intra-arterial (IA) therapy for a number of pathologies. Here, we review the anatomical, pathophysiological and experimental basis for utilisation of the MMA for IA treatment of migraine headache. We explore the in-human case literature for the treatment of headaches with IA lidocaine and discuss considerations and challenges for future research.

Association between serum uric acid, hyperuricemia and periodontitis: a cross-sectional study using NHANES data.

OBJECTIVES: Diabetes and other metabolic diseases have been linked to the development of periodontitis, but little research has been done to determine whether serum uric acid (SUA) levels and hyperuricemia play a role. This study aimed to investigate the relationship between SUA, hyperuricemia, and periodontitis. METHODS: Using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014, we created a nationally representative data set. We used multivariable logistic regression models to assess the relationship between SUA, hyperuricemia, and periodontitis and presented odds ratios (OR) in women and men, respectively. RESULTS: In women, adjusted multivariable regression models showed that SUA (4.1-4.3mg/dl) was associated with higher odds of periodontitis (OR = 1.43; 95% confidence interval (CI):1.0 ~ 2.03, p = 0.047) with SUA (≤ 3.3mg/dl) as reference. The risk of periodontitis tended to increase slightly but insignificantly with increasing SUA levels, and the adverse effects occurred only when SUA increased to a certain level, and then reached a plateau. In men, the adjusted OR values for SUA (4.9-5.2mg/dl), SUA (5.3-5.5mg/dl), SUA (5.9-6.2mg/dl), and SUA (6.3-6.5mg/dl) were 0.66 (95% CI: 0.45 ~ 0.96, p = 0.029), 0.58 (95% CI: 0.40 ~ 0.85, p = 0.006), 0.67(95% CI: 0.47 ~ 0.97, p = 0.035), and 0.67 (95% CI: 0.45 ~ 0.99, p = 0.043), respectively, with SUA (≤ 4.3mg/dl) as reference. The elevated SUA levels are protective against periodontitis, but there is a range within which the risk of periodontitis decreases, followed by a non-significant tendency to increase. CONCLUSIONS: The levels of SUA that are linked to the risk of periodontitis. Future prospective longitudinal studies and strategies are required to further confirm whether controlled SUA treatment is an effective adjunct to systematic periodontal therapy and whether SUA can be used as a diagnostic biomarker to assess the risk or progression of periodontitis.

Intercropping Sedum alfredii Hance and Cicer arietinum L. does not present a suitable land use pattern for multi-metal-polluted soil.

Intercropping of specific accumulators with industrial crops is used in moderately metal contaminated agricultural land. The distribution characteristics and environmental risks of non-accumulated ions in intercropping fields have rarely been reported. This study analyzed dissolved organic matter (DOM) fractionation and metal chemical forms to investigate the bioavailability, transformation, and uptake of non-hyperaccumulated metals in different cultivation patterns of a Cd hyperaccumulator (Sedum alfredii Hance) and a commercial crop (Cicer arietinum L.). The study focused on the distribution and transformation of heavy metals, with a particular emphasis on the role of DOM in intercropping. The contents of DOM in the rhizosphere soils of the Cd hyperaccumulator monoculture and the intercropping field were obviously greater than the DOM concentration in the commercial crop monoculture. The content of soluble Cd was significantly lower in the former two planting patterns than in the latter. In contrast, soluble Pb and Cu exhibited opposite content characteristics. In addition, the metal extraction ability of DOM extracted from the C. arietinum monoculture was lower than those from the Cd hyperaccumulator monoculture and the intercropping field. The concentrations of Cd in both below-ground and aerial parts of C. arietinum intercropping were significantly lower than those in its monoculture, since S. alfredii depleted soil Cd. Contrastingly, the contents of Cu and Pb in C. arietinum harvested from intercropping were significantly greater than those in its monoculture because the intercropped Cd hyperaccumulator activated Cu and Pb by changing soil DOM content and fractionations without absorbing them. The findings provide valuable insights into the use of intercropping to remediate moderately metal-contaminated agricultural land and highlight the potential risks associated with intercropping in multi-metal-contaminated fields.

In Situ Fabrication of Silver Peroxide Hybrid Ultrathin Co-Based Metal-Organic Frameworks for Enhanced Chemodynamic Antibacterial Therapy.

Bacterial-induced infectious diseases have always caused an unavoidable problem and lead to an increasing threat to human health. Hence, there is an urgent need for effective antibacterial strategies to treat infectious diseases. Current methods are often ineffective and require large amounts of hydrogen peroxide (H2O2), with harmful effects on normal healthy tissue. Chemodynamic therapy (CDT) provides an ideal infection microenvironment (IME)-activated paradigm to tackle bacterial-related diseases. To take full advantage of the specificity of IME and enhanced CDT for wounds with bacterial infection, we have designed an intelligent antibacterial system that exploits nanocatalytic ZIF-67@Ag2O2 nanosheets. In this system, silver peroxide nanoparticles (Ag2O2 NPs) were grown on ultrathin zeolitic imidazolate framework-67 (ZIF-67) nanosheets by in situ oxidation, and then, ZIF-67@Ag2O2 nanosheets with the ability to self-generate H2O2 were triggered by the mildly acidic environment of IME. Lamellar ZIF-67 nanosheets were shown to rapidly degrade and release Co2+, allowing the conversion of less reactive H2O2 into the highly toxic reactive oxygen species hydroxyl radicals (•OH) for enhanced CDT antibacterial properties. In vivo results revealed that the ZIF-67@Ag2O2 nanosheet system exhibits excellent antibacterial performance against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The proposed hybrid strategy demonstrates a promising therapeutic strategy to enable antibacterial agents with IME-responsive nanocatalytic activity to circumvent antibiotic resistance against bacterial infections.

Identification of optimal reference genes in golden Syrian hamster with ethanol- and palmitoleic acid-induced acute pancreatitis using quantitative real-time polymerase chain reaction.

BACKGROUND: Acute pancreatitis (AP) is a severe disorder that leads to high morbidity and mortality. Appropriate reference genes are important for gene analysis in AP. This study sought to study the expression stability of several reference genes in the golden Syrian hamster, a model of AP. METHODS: AP was induced in golden Syrian hamster by intraperitoneal injection of ethanol (1.35 g/kg) and palmitoleic acid (2 mg/kg). The expression of candidate genes, including Actb, Gapdh, Eef2, Ywhaz, Rps18, Hprt1, Tubb, Rpl13a, Nono, and B2m, in hamster pancreas at different time points (1, 3, 6, 9, and 24 h) posttreatment was analyzed using quantitative polymerase chain reaction. The expression stability of these genes was calculated using BestKeeper, Comprehensive Delta CT, NormFinder, and geNorm algorithms and RefFinder software. RESULTS: Our results show that the expression of these reference genes fluctuated during AP, of which Ywhaz and Gapdh were the most stable genes, whereas Tubb, Eef2, and Actb were the least stable genes. Furthermore, these genes were used to normalize the expression of TNF-α messenger ribonucleic acid in inflamed pancreas. CONCLUSIONS: In conclusion, Ywhaz and Gapdh were suitable reference genes for gene expression analysis in AP induced in Syrian hamster.

Relationship Between Platelets and the Clinical Efficacy of Umbilical Cord Mesenchymal Stem Cells for HBV-Related Acute-on-Chronic Liver Failure and Liver Cirrhosis: A Preliminary Clinical Study.

BACKGROUND: Previous studies have found that the production of platelets could enhance the therapeutic effects of stem cells. Nevertheless, there are still no articles reporting on the relationship between platelets and the clinical efficacy of umbilical cord mesenchymal stem cells (UCMSCs) for HBV-related acute-on-chronic liver failure (ACLF) and liver cirrhosis (LC). METHODS: In this retrospective observational study, patients who met the criteria were included. Patients were divided into subgroups according to the aims of this study. In the first part, the platelet count changes of ACLF and patients with LC after UCMSC therapy were compared and analyzed. Subgroup analysis based on UCMSC infusion times and patient age was also performed. In the second part, patients in the ACLF group and LC group were further divided into subgroups according to their platelet levels. Their clinical characteristics, demographics, and biochemical factors were compared. RESULTS: This study enrolled 64 patients with ACLF and 59 patients with LC. In both groups, platelet levels declined similarly. Compared with the short-course UCMSC treatment group (≤4 times), patients with ACLF and patients with LC with long-course UCMSC treatment (>4 times) showed an overall increasing trend. Younger patients with LC (<45 years) had significantly higher platelet levels than older patients with LC (≥45 years). However, this age difference was not present in the ACLF group. The median TBIL decrease and cumulative TBIL decrease were not significantly different between patients with high PLT and patients with low PLT after UCMSC transfusions. For patients with ACLF, the cumulative TBIL decrease and the median TBIL decrease were significantly greater than those of patients with LC at the same platelet level after UCMSC treatment. However, this difference was not observed at all time points. CONCLUSION: Trend of the platelet levels for HBV-related patients with ACLF and LC after UCMSC treatment did not parallel and varied according to treatment times and patients' age. Platelet levels did not affect the efficacy of MSCs for patients with ACLF or LC.

Molecular Dynamic Simulation of Ni-Al Alloy-H2O Reactions Using the ReaxFF Reactive Force Field.

Hydrogen as clean energy can effectively solve the problems of fossil energy shortage and environmental pollution. However, traditional methods of H2 production are generally lacking in application value. The procedure for manufacturing H2 by a reaction between active metals and H2O has received wide attention due to its high efficiency. Profound insights into the mechanism and influencing factors of H2 production from active metals are insufficient. The ReaxFF reaction force field module of the Amsterdam Modeling Suite (AMS) is applied in this paper to simulate the reaction of Ni-Al alloys with H2O. It reveals the reaction route of H2 production at the atomic level. The calculation results show that Al is the most critical active site. Moreover, the H2 production capacity of the alloy varies with the crystal structure and atomic ratio. The H2 production rate decreases due to the influence of the water solvation layer and surface coverage. Oxygen reduces the H2 production capacity because oxygen reduces the active sites for H2O adsorption by forming a stable oxide layer with Al.

Bibliometric Analysis of Research Relating to Perineal Pain Reported over the Period 1981 to 2021.

BACKGROUND: Perineal pain is a painful neuropathic condition, which does not have a standard diagnostic or treatment approach. As such, we sought to evaluate the global scientific output of research into perineal pain and explore trends from 1981 to 2021 using bibliometric methods. METHODS: Articles on perineal pain were retrieved from the Web of Science (WoS) database. We analyzed the content and quality of publications from within the specified timeframe. We also utilized VOSviewer to mine and cluster data from retrieved articles. RESULTS: A total of 1917 articles were collected. The number of related papers published increased year by year. Articles were most frequently published by authors in the United States and France. Although the US remains at the center of this field, publications from China have become more frequent in recent years. We also found that French academic institutions dominate the field of perineal pain, and Jean-Jacques Labat from Nantes Universite is the most published author in the field. "Episiotomy", "pain", "management", "prostatectomy", "pelvic pain", and "complication" were frequently cited as keywords. CONCLUSION: The increasing number of publications each year indicates that perineal pain has gained more attention as an important research topic.

Metformin enhances T lymphocyte anti-tumor immunity by increasing the infiltration via vessel normalization.

Abnormal tumor vasculature blocks the extravasation of T lymphocytes into the tumor, thereby suppressing anti-tumor immunity. Recently, metformin has been shown to affect tumor vasculature and enhance T lymphocyte anti-tumor immunity. However, whether or how metformin affects T lymphocyte anti-tumor immunity via a vascular mechanism remains poorly understood. Herein, we show that a large number of CD8+ lymphocytes gathered in the peri-tumoral region, while very few infiltrated the tumor. Metformin administration increased the expression of anti-tumor immunity-associated genes and the number of tumor-infiltrating CD8+ lymphocytes. Injection of CD8 but not CD4 neutralization antibody into tumor-bearing mice significantly abrogated the anti-tumor effect of metformin. Critically, CD8+ lymphocytes were found to pass through the wall of perfused vessel. Further results of immunofluorescent staining showed that metformin greatly elevated tumor perfusion, which was accompanied by increased vascular maturity in the intratumoral region (ITR) but not peritumoral region (PTR). These findings provide evidence for the vascular mechanism involved in metformin-induced enhancement of T lymphocyte anti-tumor immunity. By remodeling the abnormal tumor vasculature, also called vessel normalization metformin increases vascular maturity and tumor perfusion, thus allowing more CD8+ lymphocytes to infiltrate the tumor.