Quantitative Proteomic Analysis Reveals Functional Alterations of the Peripheral Immune System in Colorectal Cancer.

Colorectal cancer (CRC) is characterized by high morbidity, high mortality, and limited response to immunotherapies. The peripheral immune system is an important component of tumor immunity, and enhancements of peripheral immunity help to suppress tumor progression. However, the functional alterations of the peripheral immune system in CRC are unclear. Here, we used mass spectrometry-based quantitative proteomics to establish a protein expression atlas for the peripheral immune system in CRC, including plasma and five types of immune cells (CD4+ T cells, CD8+ T cells, monocytes, natural killer cells, and B cells). Synthesizing the results of the multidimensional analysis, we observed an enhanced inflammatory phenotype in CRC, including elevated expression of plasma inflammatory proteins, activation of the inflammatory pathway in monocytes, and increased inflammation-related ligand-receptor interactions. Notably, we observed tumor effects on peripheral T cells, including altered cell subpopulation ratios and suppression of cell function. Suppression of CD4+ T cell function is mainly mediated by high expression levels of protein tyrosine phosphatases. Among them, the expression of protein tyrosine phosphatase receptor type J (PTPRJ) gradually increased with CRC progression; knockdown of PTPRJ in vitro could promote T cell activation, thereby enhancing peripheral immunity. We also found that the combination of leucine-rich α-2 glycoprotein 1 (LRG1) and apolipoprotein A4 (APOA4) had the best predictive ability for colorectal cancer and has the potential to be a biomarker. Overall, this study provides a comprehensive understanding of the peripheral immune system in CRC. It also offers insights regarding the potential clinical utilities of these peripheral immune characteristics as diagnostic indicators and therapeutic targets.

Phosphoproteomic analysis reveals CDK5-Mediated phosphorylation of MTDH inhibits protein synthesis in microglia.

CDK5 plays a crucial role in maintaining normal central nervous system (CNS) development and synaptic function, while microglia are the primary immune cells present in the CNS and play vital physiological roles in CNS development, immune surveillance, and regulation of synaptic plasticity. Despite this, our understanding of both the substrate proteins and functional mechanisms of CDK5 in microglia remains limited. To address this, we utilized CRISPR-Cas9 knockout of Cdk5 in BV2 cells and conducted quantitative phosphoproteomics analysis to systematically screen potential CDK5 substrates in microglia. Our findings identified 335 phosphorylation sites on 234 proteins as potential CDK5 substrates in microglia based on the reported sequence motif. Through in vitro kinase assay and intracellular inhibition and knockout of CDK5 experiments, we confirmed that ER proteins MTDH (protein LYRIC) and Calnexin are novel substrate proteins of CDK5. Moreover, we demonstrated for the first time a critical mechanism for regulating protein synthesis in microglia, that the phosphorylation of S565 site on MTDH, a key protein mediating cell growth, by CDK5 inhibits protein synthesis. Our data provide valuable insights for the discovery of new substrate proteins of CDK5 and the in-depth investigation of the function and mechanism of CDK5 in microglia.

SDS3 regulates microglial inflammation by modulating the expression of the upstream kinase ASK1 in the p38 MAPK signaling pathway.

BACKGROUND: Microglia, the main innate immune cells in the central nervous system, are key drivers of neuroinflammation, which plays a crucial role in the pathogenesis of neurodegenerative diseases. The Sin3/histone deacetylase (HDAC) complex, a highly conserved multiprotein co-repressor complex, primarily performs transcriptional repression via deacetylase activity; however, the function of SDS3, which maintains the integrity of the complex, in microglia remains unclear. METHODS: To uncover the regulatory role of the transcriptional co-repressor SDS3 in microglial inflammation, we used chromatin immunoprecipitation to identify SDS3 target genes and combined with transcriptomics and proteomics analysis to explore expression changes in cells following SDS3 knocking down. Subsequently, we validated our findings through experimental assays. RESULTS: Our analysis revealed that SDS3 modulates the expression of the upstream kinase ASK1 of the p38 MAPK pathway, thus regulating the activation of signaling pathways and ultimately influencing inflammation. CONCLUSIONS: Our findings provide important evidence of the contributions of SDS3 toward microglial inflammation and offer new insights into the regulatory mechanisms of microglial inflammatory responses.

Associations of multiple serum metals with the risk of metabolic syndrome among the older population in China based on a community study: A mediation role of peripheral blood cells.

Metal exposure has been reported to be associated with metabolic syndrome (MetS), however, the evidence remains inconclusive, particularly in elderly individuals. From May to July 2016, serum levels of 16 metals were measured using inductively coupled plasma mass spectrometry (ICP-MS) in 852 elderly individuals (≥65 years) residing in Wuhan, China. Biological detection and disease recognition were based on individual surveys conducted during health check-ups. Spearman's rank correlation analysis was performed to identify the correlation among serum metals. The data were Ln-transformed to fit a normal distribution for further analyses. Linear and logistic regression were applied to explore the associations between metals and diseases. Restricted cubic spline (RCS) analysis was utilized to examine dose-response relationships. The Weighted Quantile Sum (WQS) score was applied to determine the empirical weights of each heavy metal in the context of their combined effect on metabolic diseases. The prevalence of MetS, hypertension, diabetes, and hyperlipidemia were 46.36 %, 68.90 %, 24.65 %, and 21.60 %, respectively. Serum metal mixture was positively associated with the prevalence of MetS (OR = 1.92, 95 % CI: 1.30-2.82), hypertension (OR = 1.50, 95 % CI: 1.01-2.23), and diabetes (OR = 2.18, 95 % CI: 1.48-3.22). In single metal models, we found that serum zinc levels were associated with an increased risk of MetS, while rubidium had a protective effect against MetS. Interestingly, different metals had distinct effects on specific diseases in this study: lithium and barium were more likely to influence blood pressure, while selenium had a more significant effect on blood glucose. Lipids were more susceptible to the effects of zinc, selenium, and strontium. Platelet count (PLT) and lymphocyte count (LYM) mediated the association between selenium exposure and hyperlipidemia, while neutrophil count (NEU) mediated the relationship between serum rubidium exposure and MetS. Our findings offer valuable etiological insights into the relationship between serum heavy metals and the prevalence of MetS, suggesting that peripheral blood cells may play a mediating role in this association.

Birinapant Reshapes the Tumor Immunopeptidome and Enhances Antigen Presentation.

Birinapant, an antagonist of the inhibitor of apoptosis proteins, upregulates MHCs in tumor cells and displays a better tumoricidal effect when used in combination with immune checkpoint inhibitors, indicating that Birinapant may affect the antigen presentation pathway; however, the mechanism remains elusive. Based on high-resolution mass spectrometry and in vitro and in vivo models, we adopted integrated genomics, proteomics, and immunopeptidomics strategies to study the mechanism underlying the regulation of tumor immunity by Birinapant from the perspective of antigen presentation. Firstly, in HT29 and MCF7 cells, Birinapant increased the number and abundance of immunopeptides and source proteins. Secondly, a greater number of cancer/testis antigen peptides with increased abundance and more neoantigens were identified following Birinapant treatment. Moreover, we demonstrate the existence and immunogenicity of a neoantigen derived from insertion/deletion mutation. Thirdly, in HT29 cell-derived xenograft models, Birinapant administration also reshaped the immunopeptidome, and the tumor exhibited better immunogenicity. These data suggest that Birinapant can reshape the tumor immunopeptidome with respect to quality and quantity, which improves the presentation of CTA peptides and neoantigens, thus enhancing the immunogenicity of tumor cells. Such changes may be vital to the effectiveness of combination therapy, which can be further transferred to the clinic or aid in the development of new immunotherapeutic strategies to improve the anti-tumor immune response.

Novel V-shaped kiss flap harvest technique for the forearm free flap in soft tissue reconstruction.

INTRODUCTION: Radial forearm flap (RFF) is widely used in oral reconstruction. However, the donor-site defect remains the main limit. In this paper, V-shaped kiss RFF (VRFF) is described as a novel technique to improve aesthetics and function of it. A retrospective study was conducted to introduce VRFF and evaluate its effect and safety. METHODS: A total of 21 patients who underwent VRFF for oral reconstruction, and 23 patients who underwent conventional RFF from February 2016 to April 2018 were included in this study. Direct comparisons were made on patient's subjective evaluation of postoperative hand function and degree of scarring and objective donor-site function assessment including range of wrist movements and grip strength before and after surgery between the two groups. RESULTS: No skin grafts were used in the VRFF group, and 20 of 21 patients achieved primary healing at donor site, while all patients from the RFF group had skin grafts. And 18 of 23 patients achieved primary healing. The postoperative scar score of donor site in the VRFF group was significantly higher than that in the RFF group (3.4 vs 2.8, P = 0.035). There were no significant differences in other subjective evaluation and donor-site morbidity and hand function assessment. CONCLUSION: VRFF is able to provide a new and simple method to close donor-site defect and realize a better healing in donor site.

Associations of long-term exposure to air pollution with prevalence of pulmonary nodules: A cross-sectional study in Shijiazhuang, China.

A complete understanding of the associations of ambient air pollution with prevalence of pulmonary nodule is lacking. We aimed to investigate the associations of ambient air pollutants with prevalence of pulmonary nodule. A total of 9991 health examination participants was enrolled and 3166 was elected in the final in Shijiazhuang between April 1st, 2018, and December 31st, 2018. 107 participants were diagnosed in pulmonary nodule while 3059 participants were diagnosed in non-pulmonary (named control). The individual exposure of participants was evaluation by Empirical Bayesian Kriging model according to their residential or work addresses. The pulmonary nodules were found and diagnosed by health examination through chest x-ray detection. Our results suggested that there were positive associations between prevalence of pulmonary nodules and PM2.5 (OR = 1.06, 95% CI: 1.02, 1.11) as well as O3 (OR = 1.49, 95% CI: 1.35, 1.66) levels. The platelet count (PLT) acted as the mediator of pulmonary nodules related with the PM2.5 exposure, while the neutrophil-to-lymphocyte ratio (NLR) as well as platelet-to-lymphocyte ratio (PLR) were the mediators of pulmonary nodules related with the O3 exposure. This study suggests that long-term exposure to PM2.5 and O3 may significantly associated with prevalence of pulmonary nodules, and the above associations are mediated by PLT, NLR and PLR.

Targeting NADPH Oxidase and Integrin α5ß1 to Inhibit Neutrophil Extracellular Traps-Mediated Metastasis in Colorectal Cancer.

Metastasis leads to a high mortality rate in colorectal cancer (CRC). Increased neutrophil extracellular traps (NETs) formation is one of the main causes of metastasis. However, the mechanism of NETs-mediated metastasis remains unclear and effective treatments are lacking. In this study, we found neutrophils from CRC patients have enhanced NETs formation capacity and increased NETs positively correlate with CRC progression. By quantitative proteomic analysis of clinical samples and cell lines, we found that decreased secreted protein acidic and rich in cysteine (SPARC) results in massive NETs formation and integrin α5ß1 is the hub protein of NETs-tumor cell interaction. Mechanistically, SPARC regulates the activation of the nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) pathway by interacting with the receptor for activated C kinase 1 (RACK1). Over-activated NADPH oxidase generates more reactive oxygen species (ROS), leading to the release of NETs. Then, NETs upregulate the expression of integrin α5ß1 in tumor cells, which enhances adhesion and activates the downstream signaling pathways to promote proliferation and migration. The combination of NADPH oxidase inhibitor diphenyleneiodonium chloride (DPI) and integrin α5ß1 inhibitor ATN-161 (Ac-PHSCN-NH2) effectively suppresses tumor progression in vivo. Our work reveals the mechanistic link between NETs and tumor progression and suggests a combination therapy against NETs-mediated metastasis for CRC.

Ultrasensitive detection of DNA methyltransferase activity: a novel dual-amplification fluorescence technique.

DNA methyltransferase (MTase) is an important regulatory enzyme in various biological processes. However, current methods for investigating MTase activity are still limited in terms of sensitivity and/or generality. Herein, we proposed a dual amplification fluorescence strategy for the ultrasensitive detection of DNA adenine methylation methyltransferase (Dam MTase) activity based on strand displacement amplification (SDA) coupled with rolling circle amplification (RCA). In this study, the hairpin probe could not be cleaved by Nt.AlwI nicking endonuclease (Nt.AlwI) in the presence of Dam MTase, and the subsequent SDA-RCA reaction was blocked, resulting in a weak fluorescence signal. Moreover, the blocking effect was more pronounced at a higher concentration of Dam MTase. This assay provides a very low detection limit (down to 0.0067 U ml-1), as well as good selectivity against other types of MTases (e.g., CpG methyltransferase (M.SssI MTase)). In addition, the analytical mode improves the generality and can be extended to the detection of other types of DNA MTases.

A deep analysis of the proteomic and phosphoproteomic alterations that occur in skeletal muscle after the onset of immobilization.

KEY POINTS: A decrease in protein synthesis plays a major role in the loss of muscle mass that occurs in response to immobilization. In mice, immobilization leads to a rapid (within 6 h) and progressive decrease in the rate of protein synthesis and this effect is mediated by a decrease in translational efficiency. Deep proteomic and phosphoproteomic analyses of mouse skeletal muscles revealed that the rapid immobilization-induced decrease in protein synthesis cannot be explained by changes in the abundance or phosphorylation state of proteins that have been implicated in the regulation of translation. ABSTRACT: The disuse of skeletal muscle, such as that which occurs during immobilization, can lead to the rapid loss of muscle mass, and a decrease in the rate of protein synthesis plays a major role in this process. Indeed, current dogma contends that the decrease in protein synthesis is mediated by changes in the activity of protein kinases (e.g. mTOR); however, the validity of this model has not been established. Therefore, to address this, we first subjected mice to 6, 24 or 72 h of unilateral immobilization and then used the SUnSET technique to measure changes in the relative rate of protein synthesis. The result of our initial experiments revealed that immobilization leads to a rapid (within 6 h) and progressive decrease in the rate of protein synthesis and that this effect is mediated by a decrease in translational efficiency. We then performed a deep mass spectrometry-based analysis to determine whether this effect could be explained by changes in the expression and/or phosphorylation state of proteins that regulate translation. From this analysis, we were able to quantify 4320 proteins and 15,020 unique phosphorylation sites, and surprisingly, the outcomes revealed that the rapid immobilization-induced decrease in protein synthesis could not be explained by changes in either the abundance, or phosphorylation state, of proteins. The results of our work not only challenge the current dogma in the field, but also provide an expansive resource of information for future studies that are aimed at defining how disuse leads to loss of muscle mass.

Rapid and sensitive electrochemical detection of microRNAs by gold nanoparticle-catalyzed silver enhancement.

MicroRNAs (miRNAs) have played a vital role in the regulation of gene expression and have been considered as potential biomarker candidates for early cancer diagnosis. Rapid and sensitive detection of microRNAs is highly desired. Here, we present a new method to rapidly and sensitively determine microRNAs based on the technology of gold nanoparticle catalyzed silver staining enhancement. The new method involves the sandwich hybridization of a capture probe immobilized on a magnetic bead, a reporter probe assembled on gold nanoparticles and a miRNA target, catalytic silver precipitation by gold nanoparticles, magnetic collection of the enhanced sandwich complex, dissolution of the silver precipitation and stripping detection. Using the proposed method the microRNA-7a assay was successfully carried out in less than 70 min and the detection limit was as low as 15 fM. The proposed biosensor may hold great promise in biological monitoring of microRNAs.

Factors influencing the acceptability of HIV/AIDS voluntary counselling and testing: a quantitative study of 41336 female university students in China.

This study shows that there is a huge gap between young females' willingness and practice of accepting voluntary counselling and testing (VCT). Only 2.16% (894/41336) of the participants have had HIV/AIDS tests. The study identified age, education major, confidentiality, attitude, accuracy, self-assessment and expense as major factors associated with young female people's acceptance of VCT in China. Therefore, in order to promote HIV VCT among young females, it is necessary for future programs to be sensitive to the targeted population's needs.

Long noncoding RNA LINC01133 inhibits oral squamous cell carcinoma metastasis through a feedback regulation loop with GDF15.

BACKGROUND AND OBJECTIVES: Long noncoding RNAs (lncRNAs) play key roles in carcinoma metastasis. We aimed to investigate lncRNA LINC01133 in oral squamous cell carcinoma (OSCC) metastasis. METHODS: The RNA levels of LINC01133 and growth and differentiation factor 15 (GDF15) in tissue samples from OSCC patients, and OSCC cell lines were tested by real-time quantitative polymerase chain reaction (RT-qPCR). SPSS20.0 was used to perform statistical analysis of LINC01133 expression in clinical samples and correlate expression of LINC01133 and GDF15. Cell migration/invasion was assessed via transwell assays. Downstream genes of LINC01133 were screened using RNA-seq and validated by RT-qPCR. GDF15 protein levels were evaluated via Western blot analysis. RESULTS: LINC01133 was downregulated in OSCCs; higher expression of LINC01133 in OSCCs was correlated with less metastasis and better prognosis. LINC01133 inhibited OSCC cell migration and invasion. RNA-seq data showed that LINC01133 inhibited GDF15, and GDF15 could rescue inhibition of OSCC cell migration and invasion caused by LINC01133. Interestingly, GDF15 also inhibited LINC01133. Furthermore, a significant negative correlation between expression of LINC01133 and GDF15 was validated in the clinical study. CONCLUSIONS: Collectively, these data indicate that LINC01133 inhibited OSCC metastasis via a feedback regulation loop of reciprocal inhibition with GDF15, suggesting a new diagnostic and therapeutic target for OSCC.

Crossed Total Hemiatrophy Associated with Atrophoderma of Pasini-Pierini.

A 45-year-old Chinese man had begun to show asymmetry of the face 30 years previously. Subsequently, he developed visual extinction of the right eye, slight numbness, and weakness of the left extremities. Simultaneously, multiple atrophic brownish patches occurred on his side. He denied prior trauma or tick bites at those sites. There was no report of preceding redness, induration, or a history of trauma. The atrophic lesions extended and enlarged slowly. Ten years previously, some brownish patches with normal texture had appeared on the right side of the trunk. There was no further progression of the lesions. In November 2010, the patient consulted our department for the final diagnosis and prognosis of his disease. He did not suffer from epileptic seizures and had no history of a tick bite or Lyme disease.

Chemical-oxidation cleavage triggered isothermal exponential amplification reaction for attomole gene-specific methylation analysis.

Genomic 5-methylcytosine (5-mC) modification is known to extensively regulate gene expression. The sensitive and convenient analysis of gene-specific methylation is wishful but challenging due to the lack of means that can sensitively and sequence-selectively discriminate 5-mC from cytosine without the need for polymerase chain reaction. Here we report a chemical-oxidation cleavage triggered exponential amplification reaction (EXPAR) method named COEXPAR for gene-specific methylation analysis. EXPAR was proved to not only have rapid amplification kinetics under isothermal condition but also show excellent sequence-selectivity and linear-dependence on EXPAR trigger. Further initiation of EXPAR by chemical-cleavage of DNA at 5-mC, the COEXPAR showed high specificity for methylated and nonmethylated DNA, and ∼10(7) copies of triggers were replicated in 20 min, which were used to quantify the methylation level at the methylation loci. As a result, the gene-specific methylation level of a p53 gene fragment, as a target model, was analyzed in two linear ranges of 10 fM-1 pM and 1 pM-10 nM, and limits of detection of 411 aM (S/N = 3) by fluorescence, and 576 aM (S/N = 3) by electrochemistry. The method fulfilled the assay in an isothermal way in ∼5 h without the need for tedious sample preparation and accurate thermocycling equipment, which is likely to be a facile and ultrasensitive way for gene-specific methylation analysis.

C2-ceramide induces cell death and protective autophagy in head and neck squamous cell carcinoma cells.

Ceramides are second messengers involved in several intracellular processes in cancer cells, amongst others. The aim of this study was to evaluate the anti-tumor efficacy of C2-ceramide (C2-Cer; N-acetyl-D-sphingosine) by investigating cell death and autophagy in head and neck squamous cell carcinoma (HNSCC) cells. C2-Cer showed concentration-dependent cytotoxicity in HN4 and HN30 cell lines. It simultaneously induced caspase-3-independent apoptosis and programmed necrosis. C2-Cer markedly increased the expression level of microtubule-associated protein 1 light chain 3B (LC3B) type II associated with protective autophagy. An autophagy inhibitor enhanced C2-Cer-mediated cytotoxicity, while a programmed-necrosis inhibitor produced the opposite effect. Furthermore, C2-Cer up-regulated the phosphorylation of extracellular signal-regulated kinase 1/2, but down-regulated its downstream substrate phospho-mammalian target of rapamycin (p-mTOR) during the autophagy process. These results suggested that C2-Cer exerts anti-tumor effects by inducing programmed apoptosis and necrosis in HNSCC, and these cytotoxic effects are enhanced by an autophagy inhibitor.

Centrally located acquired bilateral nevus of ota-like macules: a bizarre pattern.

A 22-year-old woman was referred to our hospital for pigmented lesions located on her face. These had gradually increased during the past 4 years. Computed tomography (CT) of her head revealed no significant parenchymal abnormalities of temporal, maxillary and sphenoid bones or of either parietal bone. Further screening, including neurologic, ophthalmologic, orthopedic, and visceral investigations, did not reveal any abnormalities. There was no family history of abnormal cutaneous pigmentation.

A three-dimensional quantitative assessment on bony growth and symmetrical recovery of mandible after decompression for unicystic ameloblastoma.

Unicystic ameloblastoma (UAM) of the jaw can be effectively reduced in volume through decompression, which promotes bone regeneration and restores jaw symmetry. This study quantitatively evaluated changes in mandible volume and symmetry following decompression of mandibular UAM. This study included 17 patients who underwent surgical decompression followed by second-stage curettage for mandibular UAM. Preoperative and postoperative three-dimensional computed tomography (CT) images were collected. Bone volume and the area of cortical perforation were measured to assess bone growth during decompression. Mandibular volumetric symmetry was analyzed by calculating the volumetric ratio of the two sides of the mandible. Twelve pairs of landmarks were identified on the surface of the lesion regions, and their coordinates were used to calculate the mean asymmetry index (AI) of the mandible. Paired t-tests and the Mann-Whitney U test were used for statistical analysis, with p < 0.05 considered indicative of statistical significance. The mean duration of decompression was 9.41 ± 3.28 months. The mean bone volume increased by 8.07 ± 2.41%, and cortical perforation recovery was 71.97 ± 14.99%. The volumetric symmetry of the mandible improved significantly (p < 0.05), and a statistically significant decrease in AI was observed (p < 0.05). In conclusion, UAM decompression enhances bone growth and symmetry recovery of the mandible. The present evaluation technique is clinically useful for quantitatively assessing mandibular asymmetry.

Female patients with hepatitis B may exhibit a reduced risk of breast cancer: A review of NHANES data.

Hepatic viral infections and breast cancer (BC) constitute major global health challenges, yet the interconnection between these hepatic infections and BC continues to be ambiguous. Conducting a comprehensive evaluation of the link between hepatitis virus infection and the incidence of BC and leveraging data from the National Health and Nutrition Examination Survey covering the period from 1999 to March 2022, we utilized logistic regression and subgroup analysis, among other methodologies, to execute a cross-sectional investigation. The univariate logistic regression analysis elucidates that individuals classified as non-Hispanic White exhibit a markedly higher incidence of BC at 2.620 (95% confidence interval [CI], 1.117-7.676; P = .045); moreover, advanced age at 1.063 (95% CI, 1.036-1.093; P < .001), elevated educational attainment at 1.962 (95% CI, 1.17-3.366; P = .012), and higher income levels at 2.835 (95% CI, 1.303-7.439; P = .017) emerge as significant predisposing factors for BC. In contrast, a greater number of live births significantly diminishes the risk of BC, reducing the incidence to 81.1% with each additional birth. Pertaining to hepatitis and vaccination status, our analysis distinctly demonstrates that only hepatitis B at 0.110 (95% CI, 0.018-0.353; P = .002) bears a significant inverse relationship with BC risk, suggesting a protective effect. The multivariate logistic regression analysis further reveals a negative association between hepatitis B infection and BC incidence, whereas hepatitis B vaccination shows a positive correlation with the disease incidence. After adjusting for all covariates, model 3 delineates odds ratios (95% CI) as follows: 0.14 (0.02-0.50; P = .009) and 1.92 (0.99-3.62; P = .046). Our investigation uncovers that within the general populace, there exists an inverse correlation between hepatitis B infection and BC incidence; in addition, the administration of the hepatitis B virus vaccine is potentially positively associated with the prevalence of BC.

Enzyme-free electrochemical biosensor based on bio-barcode amplification for ultra-sensitive detection of microRNA.

The rapid and accurate detection of miRNAs is of great significance for early diagnosis and treatment of cancer. Hence, a novel enzyme-free and label-free electrochemical biosensor based on bio-barcode amplification for detecting miRNAs was presented. Sandwich structures constructed of magnetic nanoparticles modified with DNA probes, gold nanoparticles with numerous barcoded DNA strands that hybridized with target miRNAs were fabricated as the amplifier. The released barcoded DNA strands then acted as the secondary targets and triggered the electrochemical sensor with a significant electrochemical response. A highly sensitive (detection limit of 0.24 fM) and selective electrochemical miRNA detection was realized, which has great potential for application in miRNA-related clinical diagnosis and biochemical research.