CCK-8 enhances acid-sensing ion channel currents in rat primary sensory neurons.

Cholecystokinin (CCK) is a peptide that has been implicated in pain modulation. Acid sensitive ion channels (ASICs) also play an important role in pain associated with tissue acidification. However, it is still unclear whether there is an interaction between CCK signaling and ASICs during pain process. Herein, we report that a functional link between them in rat dorsal root ganglion (DRG) neurons. Pretreatment with CCK-8 concentration-dependently increased acid-evoked ASIC currents. CCK-8 increased the maximum response of ASICs to acid, but did not changed their acid sensitivity. Enhancement of ASIC currents by CCK-8 was mediated by the stimulation of CCK2 receptor (CCK2R), rather than CCK1R. The enhancement of ASIC currents by CCK-8 was prevented by application of either G-protein inhibitor GDP-ß-S or protein kinase C (PKC) inhibitor GF109203×, but not by protein kinase A (PKA) inhibitor H-89 or JNK inhibitor SP600125. Moreover, CCK-8 increased the number of action potentials triggered by acid stimuli by activating CCK2R. Finally, CCK-8 dose-dependently exacerbated acid-induced nociceptive behavior in rats through local CCK2R. Together, these results indicated that CCK-8/CCK2R activation enhanced ASIC-mediated electrophysiological activity in DRG neurons and nociception in rats. The enhancement effect depended on G-proteins and intracellular PKC signaling rather than PKA and JNK signaling pathway. These findings provided that CCK-8/CCK2R is an important therapeutic target for ASIC-mediated pain.

Traumatic acid inhibits ACSL4 associated lipid accumulation in adipocytes to attenuate high-fat diet-induced obesity.

Obesity is a major health concern that lacks effective intervention strategies. Traumatic acid (TA) is a potent wound-healing agent in plants, considered an antioxidant food ingredient. This study demonstrated that TA treatment significantly reduced lipid accumulation in human adipocytes and prevented high-fat diet induced obesity in zebrafish. Transcriptome sequencing revealed TA-activated fatty acid (FA) degradation and FA metabolism signaling pathways. Moreover, western blotting and quantitative polymerase chain reaction showed that TA inhibited the expression of long-chain acyl-CoA synthetase-4 (ACSL4). Overexpression of ACSL4 resulted in the reversal of TA beneficiary effects, indicating that the attenuated lipid accumulation of TA was regulated by ACSL4 expression. Limited proteolysis-mass spectrometry and microscale thermophoresis were then used to confirm hexokinase 2 (HK2) as a direct molecular target of TA. Thus, we demonstrated the molecular basis of TA in regulating lipid accumulation and gave the first evidence that TA may function through the HK2-ACSL4 axis.

The impact of COVID-19 lockdown on nursing higher education at Chengdu University.

BACKGROUND: To combat/control the COVID-19 pandemic, a complete lockdown was implemented in China for almost 6 months during 2020. PURPOSE: To determine the impact of a long-term lockdown on the academic performance of first-year nursing students via mandatory online learning, and to determine the benefits of online teaching. METHODS: The recruitment and academic performance of 1st-year nursing students were assessed between 2019 [prior to COVID-19, n = 195, (146 women)] and 2020 [during COVID-19, n = 180 (142 women)]. The independent sample t test or Mann-Whitney test was applied for a comparison between these two groups. RESULTS: There was no significant difference in student recruitment between 2019 and 2020. The overall performance of the first-year students improved in the Biochemistry, Immunopathology, Traditional Chinese Medicine Nursing and Combined Nursing courses via mandatory online teaching in 2020 compared with traditional teaching in 2019. CONCLUSION: Suspension of in-class learning but continuing education virtually online has occurred without negatively impacting academic performance, thus academic goals are more than achievable in a complete lockdown situation. This study offers firm evidence to forge a path for developments in teaching methods to better incorporate virtual learning and technology in order to adapt to fast-changing environments. However, the psychological/psychiatric and physical impact of the COVID-19 lockdown and the lack of face-to-face interaction on these students remains to be explored.

N6-methyladenosine methylation mediates non-coding RNAs modification in microplastic-induced cardiac injury.

Owing to their potential adverse health effects, global contamination by microplastics (MPs) has attracted increased scientific and societal concerns. However, in vivo studies on MP toxicity, along with its effects and underlying mechanisms, remain limited. We recently found that non-coding RNA (ncRNAs) contribute to MP-mediated vascular toxicity. Moreover, previous studies have identified N6-methyladenosine (m6A) modifications in ncRNAs as influencing factors in cardiovascular disease. However, whether and how m6A modifications in ncRNAs are affected by MP-induced cardiotoxicity remain unknown. Herein, we profiled differentially expressed ncRNAs and their related m6A modification profiles in MP-exposed myocardial tissue using RNA sequencing (RNA-seq) and methylated RNA immunoprecipitation sequencing (MeRIP-seq). First, we observed that MPs accumulated in different organs and upregulated apoptosis in the heart, liver, spleen, and kidney cells. Furthermore, total m6A and METTL3 levels increased in the myocardium after exposure to MPs. RNA-seq results revealed that 392 lncRNAs and 302 circRNAs were differentially expressed in MP-treated mouse myocardium compared to the control group. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that these altered lncRNAs and circRNAs were closely associated with endocytosis, cellular senescence, and cell cycle signaling pathways, which may cause cardiotoxicity. Furthermore, MeRIP-seq data showed different distributions and abundances of m6A modifications in lncRNAs and circRNAs. Additionally, we identified differentially m6A methylated lncRNAs and circRNAs through conjoint analysis of the two high-throughput sequencing datasets and found that both m6A modifications and the expression of circ-Arfgef2 and lncG3bp2 were upregulated after exposure to MPs. This suggests that MP-induced m6A modifications in ncRNAs are involved in cardiotoxicity. Our findings contribute to a better understanding of MP-induced cardiotoxicity and new molecular targets for treating cardiac injury.

Systematic analysis of the prognostic and immunological role of DHX33 in pan-cancer.

DEAH-box helicase 33 (DHX33) is a potent oncogenic agent on patients with hepatocellular carcinoma and colon cancer. Nevertheless, the prognostic significance of DHX33 in human pan-cancers remains unclear. Various bioinformatics tools have been used to clarify the oncogenic effects of DHX33 in pan-cancers. The Cancer Genome Atlas (TCGA) and Human Protein Atlas (HPA) were used to evaluate DHX33 at the mRNA and protein levels, respectively. The pan-cancer prognostic prediction value of DHX33 was evaluated using the Kaplan-Meier plotter. The association between DHX33 levels and clinicopathological features was then determined using the UALCAN database. In addition, gene set enrichment analysis and nomogram prediction models were constructed. The association between DHX33 levels and immune cell infiltration was then assessed using TISIDB. We determined that DHX33 is aberrantly overexpressed in pan-cancers and related to lung adenocarcinoma (LUAD) clinical stage (p < .001). Moreover, DHX33 overexpression was indicative of poor overall survival, disease-free survival, and progression-free interval in patients with LUAD (p < .05). Furthermore, DHX33 levels were associated with age, N stage, T stage, and pathologic stage in patients with LUAD (p < .001). Additionally, multivariate Cox analysis revealed that DHX33 was an independent risk factor for OS in patients with LUAD. A nomogram model between DHX33 levels and characteristic clinical parameters was developed. Additionally, DHX33 levels correlated with immunomodulators and chemokines. Finally, gene set enrichment analysis revealed that the amyloid fiber formation pathway and the WICH complex positively regulates RNA expression pathway, which was the most enriched in LUAD. Our data revealed oncogenic effects of DHX33 in various cancers. We suggest that DHX33 may serve as a biomarker for poor prognosis in LUAD.

Targeting FOS attenuates malignant phenotypes of breast cancer: Evidence from in silico and in vitro studies.

Data retrieved from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases can reveal important information behind molecular biomarkers and their associated oncogenesis. Therefore, this study was based on in silico predictions and in vitro experiments to explore regulatory network associated with breast carcinogenesis. The breast cancer (BC)-related data sets were retrieved from GEO database, followed by differential analysis and protein-protein interaction (PPI) analysis. Then, Fos proto-oncogene, AP-1 transcription factor subunit (FOS)-associated gene network was constructed, and the key gene-related genes in BC were screened by LinkedOmics. Finally, FOS expression was determined in BC tissues and cells, and gain-of-function assays were performed to define the role of FOS in BC cells. It was noted that seven differentially expressed genes (EGR1, RASSF9, FOSB, CDC20, KLF4, PTGS2, and FOS) were obtained from BC microarray data sets. FOS was the gene with the most nodes in PPI analysis. Poor FOS mRNA expression was identified in BC patients. Furthermore, FOS was mainly located in the extracellular matrix and was involved in cell processes. FOS was downregulated in BC tissues and cells, and FOS overexpression restrained the malignant phenotypes of BC cells. Collectively, ectopic expression of FOS curtails the development of BC.

ELA-11 protects the heart against oxidative stress injury induced apoptosis through ERK/MAPK and PI3K/AKT signaling pathways.

Increasing evidence revealed that apoptosis and oxidative stress injury were associated with the pathophysiology of doxorubicin (DOX)-induced myocardial injury. ELABELA (ELA) is a newly identified peptide with 32 amino acids, can reduce hypertension with exogenous infusion. However, the effect of 11-residue furn-cleaved fragment (ELA-11) is still unclear. We first administrated ELA-11 in DOX-injured mice and measured the cardiac function and investigated the effect of ELA-11 in vivo. We found that ELA-11 alleviated heart injury induced by DOX and inhibited cardiac tissues from apoptosis. In vitro, ELA-11 regulated the sensitivity towards apoptosis induced by oxidative stress with DOX treatment through PI3K/AKT and ERK/MAPK signaling pathway. Similarly, ELA-11 inhibited oxidative stress-induced apoptosis in cobalt chloride (CoCl2)-injured cardiomyocytes. Moreover, ELA-11 protected cardiomyocyte by interacting with Apelin receptor (APJ) by using 4-oxo-6-((pyrimidin-2-ylthio) methyl)-4H-pyran-3-yl 4-nitrobenzoate (ML221). Hence, our results indicated a protective role of ELA-11 in oxidative stress-induced apoptosis in DOX-induced myocardial injury.

Implementation of emergency general practitioner management of patients during the complete lockdown consequent to the COVID-19 Omicron outbreak in Shanghai.

The outbreak of the Omicron strain of COVID-19 led to the most restrictive lockdowns ever implemented in Shanghai.

Effects of Clostridium butyricum Capsules Combined with Rosuvastatin on Intestinal Flora, Lipid Metabolism, Liver Function and Inflammation in NAFLD Patients.

The objective of this study was to investigate the effects of Clostridium butyricum capsules combined with rosuvastatin on the intestinal flora, lipid metabolism, liver function and inflammation in patients with nonalcoholic fatty liver disease (NAFLD). For this purpose, a total of 96 patients with NAFLD were selected as research subjects and randomly divided into a control group (n=48) and an observation group (n=48). The Control group was treated with rosuvastatin, based on which observation group received Clostridium butyricum capsule treatment. The efficacy in the two groups of patients was compared, and the intestinal flora, lipid metabolism, liver function and inflammation were observed. Results showed that the efficacy in the observation group was significantly better than that in the control group (p<0.05). After treatment, the content of Eubacterium rectale in the observation group was lower than that in the control group, while the content of Bacteroides thetaiotaomicron and Bifidobacteria was notably higher than that in the control group (p<0.05). Moreover, the observation group had remarkably lower levels of total cholesterol (TC), triglyceride (TG), free fatty acids (FFA), total bilirubin (TBIL), direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), procollagen III peptide (PIIIP), collagen-IV (C-IV), hyaluronicacid (HA) and laminin (LN) as well as lower levels of tumor necrosis factor-alpha (TNF-α), catabolite activator protein (CAP) and interleukin-6 (IL-6) in serum than the control group (p<0.05). It was concluded that Clostridium butyricum capsules combined with rosuvastatin can effectively improve intestinal flora imbalance, reduce blood lipid levels, and alleviate liver fibrosis and liver function damage in the treatment of NAFLD, so it is of therapeutic value.

A novel peptide HSP-17 ameliorates oxidative stress injury and apoptosis in H9c2 cardiomyocytes by activating the PI3K/Akt pathway.

Background: Oxidative stress and cell apoptosis play pivotal roles in the pathogenesis of doxorubicin (DOX)-induced myocardial injury. Heat shock protein-derived peptide (HSP-17) is a peptide which is low-expressed in DOX treated mouse heart tissue. It has high bioactivity and interspecies sequence consistency, and is predicted to have myocardial protective effect. Methods: Firstly, we added 1 µM DOX to H9c2 cell culture medium for 24 hours to construct the myocardial cytotoxicity model. Then we detected the effect of HSP-17 on DOX induced H9c2 cardiomyocyte injury by measuring cell viability and lactate dehydrogenase (LDH) level. In addition, reactive oxygen species (ROS) and tetraethylbenzimidazolylcarbocyanine iodide kits are used to evaluate the effect of the HSP-17 peptide on DOX-induced oxidative stress injury to cardiomyocytes, and the detection of apoptosis related proteins and flow cytometry were applied to detect the level of apoptosis. Furthermore, the protein expression levels [phosphorylated Akt (p-Akt) and phosphorylated PI3K (p-PI3K)] of the PI3K/Akt pathway were also detected by western blotting. Results: We found that the HSP-17 peptide can increase cell viability, protect mitochondrial potential, reduce LDH levels, and reduce ROS and cardiomyocyte apoptosis. In addition, we also observed that HSP-17 upregulated the expression level of p-Akt, and LY294002, a typical inhibitor of PI3K/Akt, was found to eliminate the protective roles of HSP-17. Conclusions: In conclusion, this study demonstrated that the HSP-17 peptide protected H9c2 cells against oxidative stress and apoptosis via PI3K/Akt pathway activation, which provides a new idea for the treatment of DOX-induced myocardial injury.

The Immune Subtypes and Landscape of Gastric Cancer and to Predict Based on the Whole-Slide Images Using Deep Learning.

Background: Gastric cancer (GC) is a highly heterogeneous tumor with different responses to immunotherapy. Identifying immune subtypes and landscape of GC could improve immunotherapeutic strategies. Methods: Based on the abundance of tumor-infiltrating immune cells in GC patients from The Cancer Genome Atlas, we used unsupervised consensus clustering algorithm to identify robust clusters of patients, and assessed their reproducibility in an independent cohort from Gene Expression Omnibus. We further confirmed the feasibility of our immune subtypes in five independent pan-cancer cohorts. Finally, functional enrichment analyses were provided, and a deep learning model studying the pathological images was constructed to identify the immune subtypes. Results: We identified and validated three reproducible immune subtypes presented with diverse components of tumor-infiltrating immune cells, molecular features, and clinical characteristics. An immune-inflamed subtype 3, with better prognosis and the highest immune score, had the highest abundance of CD8+ T cells, CD4+ T-activated cells, follicular helper T cells, M1 macrophages, and NK cells among three subtypes. By contrast, an immune-excluded subtype 1, with the worst prognosis and the highest stromal score, demonstrated the highest infiltration of CD4+ T resting cells, regulatory T cells, B cells, and dendritic cells, while an immune-desert subtype 2, with an intermediate prognosis and the lowest immune score, demonstrated the highest infiltration of M2 macrophages and mast cells, and the lowest infiltration of M1 macrophages. Besides, higher proportion of EVB and MSI of TCGA molecular subtyping, over expression of CTLA4, PD1, PDL1, and TP53, and low expression of JAK1 were observed in immune subtype 3, which consisted with the results from Gene Set Enrichment Analysis. These subtypes may suggest different immunotherapy strategies. Finally, deep learning can predict the immune subtypes well. Conclusion: This study offers a conceptual frame to better understand the tumor immune microenvironment of GC. Future work is required to estimate its reference value for the design of immune-related studies and immunotherapy selection.

The Impact of COVID-19 on Primary Care General Practice Consultations in a Teaching Hospital in Shanghai, China.

Background: The COVID-19 (2019 novel coronavirus disease) pandemic is deeply concerning because of its massive mortality and morbidity, creating adverse perceptions among patients likely to impact on their overall medical care. Thus, we evaluated the impact of the COVID-19 pandemic on the pattern of primary care consultations within a Shanghai health district. Methods: A retrospective observational cohort study was performed, with data analyzed concerning the pattern of patient visits to general practitioners within the Tongren Hospital network (the sole provider of general practice to the population of 700,000). Data from all general practice consultations for adults were collected for the first 6 months of 2020, which included a 60-day lockdown period (January 24-March 24, 2020) and compared to corresponding data from the first 6 months of 2019. We evaluated changes to the numbers and patterns of primary care consultations, including subgroup analysis based on age, sex, and primary diagnosis. Results: A substantial reduction in patient visits, associated with increased median age, was observed during the first wave of the pandemic in the first 6 months of 2020, compared to the same interval during 2019. Additionally, reduced reappointments and waiting times, but increased costs per visit were observed. When analyzed by primary disease diagnosis, patient visits were reduced for all the major systems. The most striking visit reductions were in cardiovascular, respiratory, endocrine, and gastrointestinal diseases. However, psychological disorders were increased following lockdown, but there was also a dramatic fall in consultations for depression. Reduced monthly patient numbers correlated with both rate of reappointment and average waiting time during the first 6 months of both 2019 and 2020, but an inverse correlation was observed between cost per visit and monthly patient numbers. Specifically during the lockdown period, there was ~50% reduced patient visits. Conclusions: The lockdown has had a serious impact on patients' physical and psychological health. Our analysis provides objective health-related data that may inform the current controversy concerning the balance between the detrimental effects of the use of lockdown vs. the use of a more targeted approach to eliminate viral transmission. These data may improve decision-making in medical practice, policy, and education.

Peptidomics analysis revealed that a novel peptide VMP­19 protects against Ang II­induced injury in human umbilical vein endothelial cells.

Vascular endothelial dysfunction is a vital pathological change in hypertension, which is mainly caused by apoptosis and oxidative stress injury of vascular endothelial cells. Peptidomics is a method for the direct analysis of small bioactive peptides in various biological samples using liquid chromatography­mass spectrometry (MS)/MS. Given the advantages of the low molecular weight, optimum targeting and easy access to cells, peptides have attracted extensive attention in the field of drug research. However, to the best of our knowledge, little is currently known regarding the role of peptides in vascular endothelial injury. In order to investigate the peptides involved in vascular endothelial protection, MS was used to analyze the peptide profiles in the supernatant of human umbilical vein endothelial cells (HUVECs) stimulated by Ang II. The results revealed that 211 peptides were identified, of which six were upregulated and 13 were downregulated when compared with the control group. Subsequently, the present study analyzed the physical and chemical properties and biological functions of identified peptides by bioinformatics, and successfully screened a peptide (LLQDSVDFSLADAINTEFK) named VMP­19 that could alleviate the apoptosis and oxidative stress injury of HUVECs induced by Ang II. In conclusion, to the best of our knowledge, the present study was the first to use peptidomics to analyze the peptide profiles of supernatant secreted by HUVECs, and revealed that the novel peptide VMP­19 could protect HUVECs from apoptosis and oxidative stress injury. The results of the present study could provide novel insights into treatment strategies for hypertension.

Clinical laboratory investigation of a patient with an extremely high D-dimer level: A case report.

BACKGROUND: D-dimer, a soluble degradation product of cross-linked fibrin, is commonly used as an important marker for the diagnosis of disseminated intravascular coagulation and differential diagnosis of thrombosis. Herein, we present a geriatric case with an unusually elevated D-dimer level. CASE SUMMARY: An 82-year-old woman, admitted to the ward with a diagnosis of chronic heart failure, was noted to have a remarkably elevated D-dimer level, beyond the qualified range (> 100 mg/L), utilizing the Innovating D-dimer for Sysmex CS-5100 System™. However, no evidence, including clinical symptoms, radiographic evidence of thromboembolic disease, and parallel fibrinogen degradation product values, suggested that this patient was at high risk of thrombopenia. To confirm the discrepancy, a series of approaches including sample dilution, re-analysis via alternative methods, and sample treatment with blockage of specific heterophilic antibodies were performed. A remarkable disappearance of the elevated D-dimer values was observed in the samples after they were subjected to these approaches (4.49, 9.42, 9.06, and 12.58 mg/L, respectively). This confirmed the presence of heterophilic antibodies in this case. In addition, a reduction in cardiac output due to the presence of cardiac failure could also be responsible for the existence of a hypercoagulable state in this case. CONCLUSION: In conclusion, the presence of heterophilic antibodies should be considered when an elevated D-dimer value is not in conformity with the clinical evidence, and a viral infection should be considered when interference by a heterophilic antibody exists.

A simulation training course for family medicine residents in China managing COVID-19.

BACKGROUND AND OBJECTIVES: As a result of the pandemic, family physicians face the additional challenge of navigating COVID-19. The aim of this study was to provide simulated training for best-practice management of COVID-19 presentations for residency program trainees in Shanghai, China. METHOD: A simulated suspected COVID-19 case was designed on the basis of a real patient. The simulation included: pre­ and post-simulation surveys, a PowerPoint presentation, simulation practice, debriefing and reflection. Improvement in survey outcomes was assessed using a paired t-test. RESULTS: A total of 25 trainees participated in the simulation, consisting of first-, second- and third-year family medicine residents. Significant improvement was observed in their knowledge of COVID-19, and sub-analysis showed that all three grades of residents improved their knowledge significantly. Ninety-six per cent of participants believed the simulation was very helpful. DISCUSSION: The simulation scenario improves crisis management skills for family physicians managing the high risk of transmission of respiratory infectious diseases. Higher-order learning outcomes will be explored in future training programs.

Self-care of medical staff in primary care: An issue that needs attention during the COVID-19 outbreak.

Self-care is essential for primary care professionals who are at risk of COVID-19.

LncRNA Blnc1 expression and its effect on renal fibrosis in diabetic nephropathy.

BACKGROUND AND OBJECTIVES: Diabetic nephropathy (DN) is one of the commonest microvascular complications of diabetes and has been the major cause of end-stage renal disease in many countries. It is of great clinical significance to further explore more efficacious therapeutic strategies for DN. This study aims to explore the effect of Blnc1 on renal fibrosis in diabetic nephropathy. METHODS: In this study, mRNA level of Blnc1 was examined by RT-PCR. HE staining and Masson staining were adopted to detect kidney damage and renal fibrosis. The renal fibrosis was evaluated by the levels of PTEN, fibronectin, collagen I and collagen IV with immunofluorescence assay and western blot analysis. Oxidative Stress and inflammatory response were detected by ELISA assay. At the same time, western blot was performed to detect the proteins related to NRF2/HO-1 and NF-κB pathways. RESULTS: Blnc1 has higher expression in serum of DN patients, STZ-induced DN model and HG-induced HK2 cells. Blnc1 interference significantly attenuated renal fibrosis, inflammation and oxidative stress via NRF2/HO-1 and NF-κB pathways. CONCLUSION: Our present study suggested that Blnc1 can affect inflammation, oxidative stress and renal fibrosis by Nrf2/HO-1 and NF-κB pathways in DN.

CTLA-4 gene polymorphisms associate with efficacy of postoperative radioiodine-131 for differentiated thyroid carcinoma.

AIM: To investigate the association of CTLA-4 polymorphisms with efficacy of postoperative radioiodine-131 (I-131) treatment for differentiated thyroid carcinoma (DTC). METHODS: A total of 324 DTC patients and 350 healthy individuals were enrolled in our study. Patients received I-131 remnant ablation following surgical resection. Based on the treatment efficacy, patients were divided into the effective (n = 183) and ineffective groups (n = 141). CTLA-4 polymorphisms (+49A>G, CT60A>G and -318C>T) were genotyped by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: AG + AA genotype distribution and A allele frequency of +49A>G and CT60A>G polymorphisms were higher in the effective group than the ineffective group. CONCLUSION: +49A>G and CT60A>G polymorphisms were associated with the efficacy of postoperative I-131 treatment for DTC; and they might be bioindicators related to the prognosis of I-131 treatment.

Relationship between VEGF protein expression and lymph node metastasis in papillary thyroid carcinoma among Asians: a meta-analysis.

We carried out the current meta-analysis of relevant cohort studies in an attempt to investigate the relationships between vascular endothelial growth factor (VEGF) protein expression and lymph node (LN) metastasis in papillary thyroid carcinoma (PTC) among Asians. A range of electronic databases were searched, including Web of Science (1945∼2013), the Cochrane Library Database (Issue 12, 2013), MEDLINE (1966∼2013), EMBASE (1980∼2013), CINAHL (1982∼2013), and Chinese Biomedical Database (CBM) (1982~2013) with cross-referencing without language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Crude odds ratio (OR) with their 95 % confidence interval (95 %CI) was calculated. Twelve clinical cohort studies with a total of 1,045 PTC patients were included in our meta-analysis, The results of our meta-analysis revealed that patients with VEGF-positive tumors had a 3.02-fold higher risk of LN metastasis than that of patients with VEGF-negative tumors (OR=3.02, 95 %CI=2.05~4.43, P<0.001). Furthermore, subgroup analysis by country suggested that VEGF-positive expression was associated with an increased risk of LN metastasis in PTC patients among Chinese populations (OR=3.33, 95 %CI=2.30~4.83, P<0.001), but not among Korean, Turkish, and Japanese populations (all P>0.05). Our findings support the view that VEGF protein expression may be correlated with LN metastasis in PTC patients, especially among Chinese populations.