KCNK1 promotes proliferation and metastasis of breast cancer cells by activating lactate dehydrogenase A (LDHA) and up-regulating H3K18 lactylation.

Breast cancer is the most prevalent malignancy and the most significant contributor to mortality in female oncology patients. Potassium Two Pore Domain Channel Subfamily K Member 1 (KCNK1) is differentially expressed in a variety of tumors, but the mechanism of its function in breast cancer is unknown. In this study, we found for the first time that KCNK1 was significantly up-regulated in human breast cancer and was correlated with poor prognosis in breast cancer patients. KCNK1 promoted breast cancer proliferation, invasion, and metastasis in vitro and vivo. Further studies unexpectedly revealed that KCNK1 increased the glycolysis and lactate production in breast cancer cells by binding to and activating lactate dehydrogenase A (LDHA), which promoted histones lysine lactylation to induce the expression of a series of downstream genes and LDHA itself. Notably, increased expression of LDHA served as a vicious positive feedback to reduce tumor cell stiffness and adhesion, which eventually resulted in the proliferation, invasion, and metastasis of breast cancer. In conclusion, our results suggest that KCNK1 may serve as a potential breast cancer biomarker, and deeper insight into the cancer-promoting mechanism of KCNK1 may uncover a novel therapeutic target for breast cancer treatment.

Regulatory gene network for coffee-like color morph of TYRP1 mutant of oujiang color common carp.

BACKGROUND: Neither a TYRP1-mediated highly conserved genetic network underlying skin color towards optimum defense nor the pathological tendency of its mutation is well understood. The Oujiang Color Common Carp (Cyprinus carpio var. color) as a model organism, offering valuable insights into genetics, coloration, aquaculture practices, and environmental health. Here, we performed a comparative skin transcriptome analysis on TYRP1 mutant and wild fishes by applying a conservative categorical approach considering different color phenotypes. RESULTS: Our results reveal that an unusual color phenotype may be sensitized with TYRP1 mutation as a result of upregulating several genes related to an anti-inflammatory autoimmune system in response to the COMT-mediated catecholamine neurotransmitters in the skin. Particularly, catecholamines-derived red/brown, red with blue colored membrane attack complex, and brown/grey colored reduced eumelanin are expected to be aggregated in the regenerated cells. CONCLUSIONS: It is, thus, concluded that the regenerated cells with catecholamines, membrane attack complex, and eumelanin altogether may contribute to the formation of the unusual (coffee-like) color phenotype in TYRP1 mutant.

RNA modifications in cancer.

Currently, more than 170 modifications have been identified on RNA. Among these RNA modifications, various methylations account for two-thirds of total cases and exist on almost all RNAs. Roles of RNA modifications in cancer are garnering increasing interest. The research on m6A RNA methylation in cancer is in full swing at present. However, there are still many other popular RNA modifications involved in the regulation of gene expression post-transcriptionally besides m6A RNA methylation. In this review, we focus on several important RNA modifications including m1A, m5C, m7G, 2'-O-Me, Ψ and A-to-I editing in cancer, which will provide a new perspective on tumourigenesis by peeking into the complex regulatory network of epigenetic RNA modifications, transcript processing, and protein translation.

Identification of fibrosis in hypertrophic cardiomyopathy: a radiomic study on cardiac magnetic resonance cine imaging.

OBJECTIVES: Hypertrophic cardiomyopathy (HCM) often requires repeated enhanced cardiac magnetic resonance (CMR) imaging to detect fibrosis. We aimed to develop a practical model based on cine imaging to help identify patients with high risk of fibrosis and screen out patients without fibrosis to avoid unnecessary injection of contrast. METHODS: A total of 273 patients with HCM were divided into training and test sets at a ratio of 7:3. Logistic regression analysis was used to find predictive image features to construct CMR model. Radiomic features were derived from the maximal wall thickness (MWT) slice and entire left ventricular (LV) myocardium. Extreme gradient boosting was used to build radiomic models. Integrated models were established by fusing image features and radiomic models. The model performance was validated in the test set and assessed by ROC and calibration curve and decision curve analysis (DCA). RESULTS: We established five prediction models, including CMR, R1 (based on the MWT slice), R2 (based on the entire LV myocardium), and two integrated models (ICMR+R1 and ICMR+R2). In the test set, ICMR+R2 model had an excellent AUC value (0.898), diagnostic accuracy (89.02%), sensitivity (92.54%), and F1 score (93.23%) in identifying patients with positive late gadolinium enhancement. The calibration plots and DCA indicated that ICMR+R2 model was well-calibrated and presented a better net benefit than other models. CONCLUSIONS: A predictive model that fused image and radiomic features from the entire LV myocardium had good diagnostic performance, robustness, and clinical utility. KEY POINTS: • Hypertrophic cardiomyopathy is prone to fibrosis, requiring patients to undergo repeated enhanced cardiac magnetic resonance imaging to detect fibrosis over their lifetime follow-up. • A predictive model based on the entire left ventricular myocardium outperformed a model based on a slice of the maximal wall thickness. • A predictive model that fused image and radiomic features from the entire left ventricular myocardium had excellent diagnostic performance, robustness, and clinical utility.

Ocular Mycobacterium haemophilum infection originating in the cornea: a case report.

BACKGROUND: Mycobacterium haemophilum is a slow-growing non-chromogenic nontuberculous Mycobacterium species that can cause skin infection or arthritis in an immunocompromised population or in children. Primary infection of the healthy adult cornea is rare. The special requirements for culture make this pathogen difficult to diagnose. The study aims to report the clinical manifestation and treatment process of corneal infection and notify the awareness of M. Haemophilus keratitis among clinicians. This is the first case report of primary M. haemophilum infection in the cornea of healthy adults reported in the literature. CASE PRESENTATION: A 53-year-old healthy goldminer presented with left eye redness and a history of vision loss for four months. The patient was misdiagnosed with herpes simplex keratitis until M. haemophilum was detected using high-throughput sequencing. Penetrating keratoplasty was performed, and a large number of mycobacteria were detected by Ziehl-Neelsen staining of the infected tissue. Three months later, the patient developed conjunctival and eyelid skin infections that manifested as caseous necrosis of the conjunctiva and skin nodules. After excision and debridement of the conjunctival lesions and systemic antituberculosis drug treatment for 10 months, the patient was cured. CONCLUSION: M. haemophilum could cause primary corneal infection in healthy adults, which is an infrequent or rare infection. Owing to the need for special bacterial culture conditions, conventional culture methods do not provide positive results. High-throughput sequencing can rapidly identify the presence of bacteria, which aids in early diagnosis and timely treatment. Prompt surgical intervention is an effective treatment option for severe keratitis. Long-term systemic antimicrobial therapy is crucial.

Splicing factor derived circular RNA circCAMSAP1 accelerates nasopharyngeal carcinoma tumorigenesis via a SERPINH1/c-Myc positive feedback loop.

BACKGROUND: Circular RNAs play an important role in tumor genesis and progression, but they have not been sufficiently studied in patients with nasopharyngeal carcinoma (NPC). METHODS: The circular RNA, circCAMSAP1, was screened in NPC cells by RNA sequencing analysis. The expression of circCAMSAP1 in NPC tissues was examined by real-time quantitative polymerase chain reaction (RT-qPCR) and in situ hybridization. Wound-healing, transwell, MTT and flow cytometry assays, and nude mouse tumor models were used to explore the effect of circCAMSAP1 on proliferation and metastasis of NPC in vitro or in vivo. The downstream proteins regulated by circCAMSAP1 were screened using mass spectrometry. The interaction between circCAMSAP1 and the SERPINH1 mRNA was identified using the circular RNA immunoprecipitation method and the luciferase reporter assay. The interaction between SERPINH1 and transcription factor c-Myc was verified through Co-immunoprecipitation (Co-IP) and immunofluorescence. The effect of c-Myc on the generation of circCAMSAP1 was examined through RT-qPCR and chromatin immunoprecipitation. Finally, the splicing factors that promote the production of circCAMSAP1 were explored by RT-qPCR and RNA immunoprecipitation (RIP). RESULTS: We found that circCAMSAP1 was highly expressed in NPC tissues and promoted NPC proliferation and metastasis. Additionally, circCAMSAP1 promoted SERPINH1 expression through improved SERPINH1 mRNA stability by binding to the 3'-untranslated region (3'UTR) of SERPINH1. Highly expressed SERPINH1 reduced the ubiquitination-degradation rate of c-Myc, causing increased tumorigenesis. Meanwhile, c-Myc, cooperating with splicing factor 10 (SRSF10), could also promote CAMSAP1 pre-mRNA transcription and back-splicing, forming a positive feedback of circCAMSAP1 production, resulting in the proliferation and metastasis of NPC. CONCLUSIONS: Our findings revealed that circCAMSAP1 promotes NPC proliferation and metastasis by binding to the 3'UTR of SERPINH1, suggesting that the positive feedback of circCAMSAP1-SERPINH1-c-Myc may serve as a prognostic biomarker or therapeutic target in patients with NPC.

Tim-3: An inhibitory immune checkpoint is associated with maternal-fetal tolerance and recurrent spontaneous abortion.

The establishment and maintenance of pregnancy are involved in maternal-fetal immune tolerance whose imbalance can lead to recurrent spontaneous abortion (RSA). RSA is defined as two or more clinically recognized pregnancy losses within 20-24 weeks of gestation with the same partner, including embryonic and fetal losses. However, approximately half of RSA cases are idiopathic, which may be related to immune aberrations. T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) is an inhibitory checkpoint protein that plays a critical role in immune tolerance. Several studies have reported that Tim-3 expression in immune cells is important for maintaining maternal-fetal immune tolerance and that the abnormal expression of Tim-3 may be associated with RSA. To further understand the etiology and pathogenesis of RSA and inspire novel strategies for its diagnosis and treatment, we reviewed the research progress on the Tim-3-induced regulation of natural killer cells, T cells, macrophages, dendritic cells, and myeloid-derived suppressor cells in maternal-fetal immune tolerance and RSA.

Evaluation of a novel recombinant strain of infectious bronchitis virus emerged from three attenuated live vaccine strains.

Infectious bronchitis virus (IBV) causes avian infectious bronchitis (IB) and there are multiple serotypes worldwide originating from deletions, insertions, point mutations, and RNA recombination. In this study, a recombinant IBV, named CK/CH/MY/2020, was isolated from southwest China. Sequencing and phylogenetic analysis revealed that CK/CH/MY/2020 consists of 27,614 nucleotides and belongs to the GI-28 genotype. Moreover, the strain is a recombination product originating from three live attenuated vaccine strains (H120, 4/91, and LDT3-A). The recombination is complicated involving at least nine recombination sites; the first 3/5 portion is mainly composed of H120 and 4/91, and the second 2/5 contains LDT3-A. Pathogenicity analysis showed that CK/CH/MY/2020 could cause respiratory and kidney diseases in chickens resulting in moderate mortality. Therefore, the recombinant strain is more virulent than the attenuated vaccine strains. This study shows that even in the absence of wild strains, the recombination and revirulence of multiple attenuated vaccines could occur simultaneously, which also highlights the continuous evolution in IBV.

IGF-1 contributes to liver cancer development in diabetes patients by promoting autophagy.

INTRODUCTION AND OBJECTIVES: Type 2 diabetes mellitus (T2DM) increases the occurrence and mortality of liver cancer. Insulin growth factor (IGF) plays a crucial role in the development of diabetes and liver cancer, and specifically, IGF-1 may be involved in the development of liver cancer with preexisting T2DM. Autophagy contributes to cancer cell survival and apoptosis. However, the relationship between IGF-1 and autophagy has rarely been evaluated. The purpose of this study was to investigate whether IGF-1 promotes the development of liver cancer in T2DM patients by promoting autophagy. MATERIALS AND METHODS: Thirty-three hepatocellular carcinoma (HCC) patients with T2DM and 33 age-matched patients with HCC without T2DM were included in this study. We analyzed the expression of IGF-1 and autophagy-related LC3 and p62 mRNA and the prognosis of two groups. In vitro, we stimulated HepG2 cells with IGF-1 and then detected changes in autophagy and cell proliferation, apoptosis, and migration in the presence/absence of wortmannin, an autophagy inhibitor. RESULTS: IGF-1 promoted autophagy, resulting in inhibition of apoptosis and induction of growth and migration of HepG2 cells. Inhibition of autophagy by wortmannin impaired IGF-1 function. Higher expression of IGF-1 was detected in HCC patients with T2DM. IGF-1 expression was higher in liver cancer tissue compared to paracancerous tissue. Elevated IGF-1 was associated with a poor prognosis in patients with HCC. CONCLUSIONS: IGF-1 participates in the development of liver cancer by inducing autophagy. Elevated IGF-1 was a prognostic factor for patients with HCC, especially when accompanied by T2DM.

Circular RNA circRNF13 inhibits proliferation and metastasis of nasopharyngeal carcinoma via SUMO2.

BACKGROUND: Circular RNAs (circRNAs) are widely expressed in human cells and are closely associated with cancer development. However, they have rarely been investigated in the context of nasopharyngeal carcinoma (NPC). METHODS: We screened a new circRNA, circRNF13, in NPC cells using next-generation sequencing of mRNA. Reverse transcription polymerase chain reaction and RNA fluorescence in situ hybridization were used to detect circRNF13 expression in 12 non-tumor nasopharyngeal epithelial (NPE) tissues and 36 NPC samples. Cell proliferation was detected using MTT and flow cytometry assays, and colony formation capability was detected using colony formation assays. Cell migration and invasion were analyzed using wound-healing and Transwell assays, respectively. Cell glycolysis was analyzed using the Seahorse glycolytic stress test. Glucose transporter type 1 (GLUT1) ubiquitination and SUMOylation modifications were analyzed using co-immunoprecipitation and western blotting. CircRNF13 and Small Ubiquitin-like Modifier 2 (SUMO2) interactions were analyzed using RNA pull-down and luciferase reporter assays. Finally, to test whether circRNF13 inhibited NPC proliferation and metastasis in vivo, we used a xenograft nude mouse model generated by means of subcutaneous or tail vein injection. RESULTS: We found that circRNF13 was stably expressed at low levels in NPC clinical tissues and NPC cells. In vitro and in vivo experiments showed that circRNF13 inhibited NPC proliferation and metastasis. Moreover, circRNF13 activated the SUMO2 protein by binding to the 3'- Untranslated Region (3'-UTR) of the SUMO2 gene and prolonging the half-life of SUMO2 mRNA. Upregulation of SUMO2 promotes GLUT1 degradation through SUMOylation and ubiquitination of GLUT1, which regulates the AMPK-mTOR pathway by inhibiting glycolysis, ultimately resulting in the proliferation and metastasis of NPC. CONCLUSIONS: Our results revealed that a novel circRNF13 plays an important role in the development of NPC through the circRNF13-SUMO2-GLUT1 axis. This study implies that circRNF13 mediates glycolysis in NPC by binding to SUMO2 and provides an important theoretical basis for further elucidating the pathogenesis of NPC and targeted therapy.

Circulating miRNAs miR-574-5p and miR-3135b are potential metabolic regulators for serum lipids and blood glucose in gestational diabetes mellitus.

OBJECTIVES: MicroRNAs (miRNAs) are potentially involved in the regulation of glucose and lipid metabolism. The aim of this study was to investigate potential miRNA regulators for serum lipids and blood glucose in gestational diabetes mellitus. METHODS: Plasma samples were obtained from 53 women with GDM and 46 normal pregnant women. Fasting blood glucose and a blood lipid profile were measured. Plasma miRNA expression profiles were analyzed using microarray. To verify the microarray data, the expression of miRNAs was evaluated by real-time PCR. Gene ontology (GO) and genes and genomics (KEGG) pathway enrichment of the predicted target genes of miRNAs were analyzed. RESULTS: The miRNA expression profiles of plasma samples from healthy and GDM women are distinct. We identified 93 differently expressed miRNAs. Compared with healthy pregnant women, 48 miRNAs including miR-574-5p and miR-3135b exhibited significantly lower expression in plasma samples from GDM patients. The expression of miR-574-5p was significantly correlated with levels of blood glucose and LDL-C; miR-3135b was significantly correlated with HDL-C. Some predicted common target genes of these two miRNAs are associated with the metabolism of glucose and lipids as well as the insulin signaling pathway. CONCLUSIONS: miR-574-5p and miR-3135b may serve as metabolic regulators of glucose and lipids for GDM.

Chlamydia trachomatis induces autophagy by p62 in HeLa cell.

Chlamydia trachomatis is the most common bacterial pathogen causing sexually transmitted diseases. C. trachomatis infection is closely related to the development of cervical cancer, studies have shown that C. trachomatis can induce host cell autophagy. The autophagy related gene p62 plays an important role in the process of autophagy. To further understand the role of autophagy-associated gene p62 in autophagy of HeLa cells induced by C. trachomatis, p62-silencing cell line, HeLa229-shp62, and control cell line, HeLa229-shNC, were constructed, and a C. trachomatis-infected cell model was established. The autophagosome and C. trachomatis inclusions were observed under electron microscope. The autophagy level of C. trachomatis-infected HeLa cells was detected by Western blot. The results suggested that knockdown of p62 affected neither C. trachomatis infection of HeLa cells nor the initiation of C. trachomatis-induced autophagy, but at 48 h post C. trachomatis infection, autophagy levels were significantly inhibited in p62 silencing host cells. The study demonstrated the important role of p62 in the autophagy induced by C. trachomatis in HeLa cells, which could provide data support and theoretical basis for exploring the pathogenesis and prevention of C. trachomatis.

Scleral defect repair using decellularized porcine sclera in a rabbit model.

BACKGROUND: The sclera is one of the most commonly used repair materials in ophthalmic plastic surgery and is often used for supporting, wrapping, filling, and pressing during surgery. Although the sclera plays an irreplaceable role in ophthalmology applications, there are many restrictive factors, such as high costs and limited sources. Here, we report the use of a decellularized porcine sclera (DPS) for scleral reconstruction in rabbit models. METHODS: The DPS generated by a hybrid decellularization protocol was characterized in respect of histological observation, DNA, α-gal, GAG, and collagen content. The mechanical properties were evaluated by uniaxial tensile testing. LIVE/DEAD and Cell Counting Kit (CCK)-8 assays were performed to assess its in vitro cytocompatibility and cytotoxicity. In vivo biocompatibility and biointegration of the DPS for repairing scleral defect in rabbit were measured by slit-lamp and histological analyses. Immunohistochemical (IHC) staining was used to detect the expression of CD4, CD8, CD45, CD68, and vimentin. RESULTS: Through decellularization, the major xenoantigen DNA and α-gal are efficiently removed while abundant matrix components and mechanical properties are well preserved in the DPS. Extracts of the DPS and DPS samples had no inhibitory effects on the proliferation of HFSFs. Moreover, there was no sign that an immune reaction occurred in or around the transplanted DPS grafts within 28 days of animal implantation. CONCLUSION: The decellularization strategy we developed is feasible and effective. The prepared DPS holds great potential for the repair of scleral injury.

Correlation analysis of the clinical features and prognosis of acute ocular burns-exploration of a new classification scheme.

PURPOSE: To explore a new classification scheme for acute ocular burns. METHODS: Medical records of 345 patients (450 eyes) with acute ocular burns treated at Shandong Eye Institute between January 2013 and January 2018 with a 12-month minimum follow-up were retrospectively reviewed. A total of 8 parameters in the acute phase were evaluated and graded on a scale from 0 to 3 according to their severity. RESULTS: The key factors affecting the prognosis of acute ocular burns were conjunctival involvement (386 eyes, 85.8%), corneal epithelial defect (349 eyes, 77.6%), and limbal ischemia (244 eyes, 54.2%). Visual acuity in 181/450 eyes (40.2%) was worse than 6/60. The injury severity of the cornea, limbus, bulbar conjunctiva, eyelid, and fornix and intraocular signs in the acute phase was significantly correlated with the logarithm of the minimum angle of resolution (logMAR) visual acuity (correlation coefficient [R] 0.481-0.933, P < 0.0001) and corneal opacification, neovascularization, and symblepharon scores in the stable phase (R 0.513-0.855, P < 0.0001). The mean total score for the 8 parameters in the acute phase was 5.34 ± 4.04 (range 0-14); higher scores indicated worse visual acuity (R = 0.899, P < 0.0001). The total score for acute-phase parameters was significantly correlated with that for the stable-phase parameters (R = 0.872, P < 0.0001). CONCLUSIONS: The severity of acute-phase parameters is significantly correlated with the final visual outcome and prognosis. The new grading scheme can help clinicians more accurately analyze the degree of ocular burns, determine a reasonable treatment protocol, and rationally evaluate the prognosis.

Comparing hepatic steatosis distribution patterns between non-alcoholic fatty liver disease and fatty liver disease with chronic hepatitis B by second-harmonic generation/two-photon excited fluorescence method.

INTRODUCTION AND OBJECTIVES: Hepatitis B virus (HBV) might be an etiological factor modulating fat distribution in steatotic livers. We aim to compare hepatic steatosis distribution patterns between NAFLD and FL&CHB patients with second-harmonic generation (SHG)/two-photon excited fluorescence (TPEF) method. PATIENTS AND METHODS: 42 patients with NAFLD, 46 with FL&CHB and 55 without steatosis were enrolled in the study. Overall and regional steatosis in liver sections were quantified by SHG/TPEF method. The accuracy of which was validated by pathologist evaluation and magnetic resonance spectroscopy (MRS). Difference in degree of overall and regional steatosis between NAFLD and FL&CHB groups was analyzed by Mann-Whitney U test. Multivariable linear regression analysis was used to model factors contributing to steatosis distribution. RESULTS: The hepatic steatosis measured by SHG/TPEF method was highly correlated with pathologist grading (r=0.83, p<0.001) and MRS measurement (r=0.82, p<0.001). The level of overall steatosis in FL&CHB group is significantly lower than that in NAFLD group (p<0.001). In NAFLD group, periportal region has significantly lower steatosis percentage than lobule region and overall region (p<0.001); while in FL&CHB group there is no difference among regions. The ratio of steatosis at periportal region to lobule region is significantly higher in FL&CHB group than that in NAFLD group (p<0.05). Multivariable linear regression analysis shows that HBV infection is the major contributing factor (ß=0.322, p<0.01). CONCLUSIONS: SHG/TPEF method is an accurate and objective method in hepatic steatosis quantification. By quantifying steatosis in different histological regions, we found steatosis distribution patterns are different between FL&CHB and NAFLD patients.

Natural killer group 2D receptor and its ligands in cancer immune escape.

The immune system plays important roles in tumor development. According to the immune-editing theory, immune escape is the key to tumor survival, and exploring the mechanisms of tumor immune escape can provide a new basis for the treatment of tumors. In this review, we describe the mechanisms of natural killer group 2D (NKG2D) receptor and NKG2D ligand (NKG2DL) in tumor immune responses.Natural killer (NK) cells are important cytotoxic cells in the immune system, and the activated NKG2D receptor on the NK cell surface can bind to NKG2DL expressed in tumor cells, enabling NK cells to activate and kill tumor cells. However, tumors can escape the immune clearance mediated by NKG2D receptor/NKG2DL through various mechanisms. The expression of NKG2D receptor on NK cells can be regulated by cells, molecules, and hypoxia in the tumor microenvironment. Tumor cells regulate the expression of NKG2DL at the level of transcription, translation, and post-translation and thereby escape recognition by NK cells. In particular, viruses and hormones have special mechanisms to affect the expression of NKG2D receptor and NKG2DL. Therefore, NKG2D\NKG2DL may have applications as targets for more effective antitumor therapy.

Single-Particle LRET Aptasensor for the Sensitive Detection of Aflatoxin B1 with Upconversion Nanoparticles.

Contamination of foods and feeds by aflatoxins is a universal yet serious problem all over the world. Particularly, aflatoxin B1 (AFB1) is the most primary form and readily leads to terrible damages to human health. In this work, we construct a sensitive aptasensor based on single-particle detection (SPD) to analyze AFB1 in peanut samples with luminescence resonance energy transfer (LRET) between the aptamer-modified upconversion nanoparticles (UCNPs-aptamer) and gold nanoparticles (GNPs). The UCNP-aptamer plays as the luminescence donor, while GNP acts as the energy acceptor. In the absence of AFB1, GNPs would adsorb onto the surface of UCNPs-aptamer because of the association between aptamers and GNPs, leading to luminescence quenching. However, the luminescence of UCNPs-aptamer is recovered gradually in the presence of AFB1, because the aptamers possess stronger affinity toward AFB1 than GNPs. Through statistically counting the number of luminescent particles on the glass slide surface, the concentration of AFB1 in solution is accurately determined. The linear dynamic range for AFB1 detection is from 3.13 to 125.00 ng/mL. The limit-of-detection (LOD) is 0.17 ng/mL, which is much lower than the allowable concentration in foods. As a result, this method would provide promising application for the sensitive detection of AFB1 in foods and feeds, which might make a meaningful contribution to food safety and public health in the future.

Single-Particle Enzyme Activity Assay with Spectral-Resolved Dark-Field Optical Microscopy.

In a clinical assay, enzymes are essential biomarkers for human disease diagnosis. In this work, a spectral-resolved single-particle detection (SPD) method is introduced to quantify alkaline phosphatase (ALP) activity in human serum with a supraparticle (SP) based on MnO2-modified gold nanoparticle (denoted as GNP@MnO2 SP) as the probe. In the presence of ALP, 2-phospho-l-ascorbic acid trisodium salt can be hydrolyzed into l-ascorbic acid, which serves as a good reduction agent to trigger the decomposition of the MnO2 shell on the GNP surface. Given that a trace amount of ALP exists, noticeable scattering color change can be detected at the single-particle level due to the sensitive localized surface plasmon resonance (LSPR) effect from GNPs. With spectral-resolved dark-field optical microscopy, a linear dynamic range of 0.06 to 2.48 mU/mL ( R2 = 0.99) and a very low limit of detection of 5.8 µU/mL for the ALP assay are readily achieved, which is more sensitive over the methods based on ensemble sample measurement. As a consequence, this strategy opens a new avenue for the design of an ultrasensitive detection method for disease-correlated biomarker diagnosis in the future.

A novel protease inhibitor causes inclusion vacuole reduction and disrupts the intracellular growth of Chlamydia trachomatis.

Chlamydia (C.) trachomatis, characterized by a unique biphasic life cycle, is an obligate intracellular bacterial pathogen which is responsible for the highest number of sexually transmitted bacterial infections globally. However, its pathogenic mechanisms have not been fully elucidated because of its unique developmental cycle and obligate intracellular nature. High temperature requirement (HtrA), a critical protease and chaperone, has been previously demonstrated to be essential for several functions and the replicative phase in the C. trachomatis developmental cycle. In the current study, we designed and synthesized a novel peptidomimetic inhibitor targeting C. trachomatis HtrA (CtHtrA) using homology modeling and chemical synthesis. The inhibitor was tested in chlamydia in the mid-replicative phase and resulted in a significant loss of viable infectious progeny and diminishing inclusion size and number at a relatively low concentration. This finding not only indicates that CtHtrA plays a critical role during the replicative phase of the chlamydial developmental cycle but also reveals a useful target for the design of novel anti-chlamydial agents.

Inflammatory mechanism of Chlamydia trachomatis-infected HeLa229 cells regulated by Atg5.

The relation between autophagy and Chlamydia trachomatis infection remain inconclusive. In order to further understand the role of autophagy in C. trachomatis-infected cells. Atg5 silenced HeLa229 cell line was used to establish an autophagy inhibition C. trachomatis infection model. The results suggested that Atg5 served a key regulatory role in the autophagy of C. trachomatis-infected cells. Silencing Atg5 significantly inhibited the autophagy level of the infected cells. Furthermore, Atg5 knockdown led to increased secretion of proinflammatory cytokines IL-1ß, IL-6, IFN-γ and TNF-α, and decreased secretion of anti-inflammatory cytokine IL-10 in C. trachomatis-infected cells after autophagy induction, which suggested the anti-inflammatory role of autophagy during chlamydia infection. This study reveals some physiological and pathological roles of autophagy during C. trachomatis infection, which would provide clues in the treatment of chronic chlamydia infection.