Unveiling the Role of Protein Kinase C θ in Porcine Epidemic Diarrhea Virus Replication: Insights from Genome-Wide CRISPR/Cas9 Library Screening.

Porcine epidemic diarrhea virus (PEDV), a member of the Alpha-coronavirus genus in the Coronaviridae family, induces acute diarrhea, vomiting, and dehydration in neonatal piglets. This study aimed to investigate the genetic dependencies of PEDV and identify potential therapeutic targets by using a single-guide RNA (sgRNA) lentiviral library to screen host factors required for PEDV infection. Protein kinase C θ (PKCθ), a calcium-independent member of the PKC family localized in the cell membrane, was found to be a crucial host factor in PEDV infection. The investigation of PEDV infection was limited in Vero and porcine epithelial cell-jejunum 2 (IPEC-J2) due to defective interferon production in Vero and the poor replication of PEDV in IPEC-J2. Therefore, identifying suitable cells for PEDV investigation is crucial. The findings of this study reveal that human embryonic kidney (HEK) 293T and L929 cells, but not Vero and IPEC-J2 cells, were suitable for investigating PEDV infection. PKCθ played a significant role in endocytosis and the replication of PEDV, and PEDV regulated the expression and phosphorylation of PKCθ. Apoptosis was found to be involved in PEDV replication, as the virus activated the PKCθ-B-cell lymphoma 2 (BCL-2) ovarian killer (BOK) axis in HEK293T and L929 cells to increase viral endocytosis and replication via mitochondrial apoptosis. This study demonstrated the suitability of HEK293T and L929 cells for investigating PEDV infection and identified PKCθ as a host factor essential for PEDV infection. These findings provide valuable insights for the development of strategies and drug targets for PEDV infection.

Overlapping cytoplasms segmentation via constrained multi-shape evolution for cervical cancer screening.

Segmenting overlapping cytoplasms in cervical smear images is a clinically essential task for quantitatively measuring cell-level features to screen cervical cancer This task, however, remains rather challenging, mainly due to the deficiency of intensity (or color) information in the overlapping region Although shape prior-based models that compensate intensity deficiency by introducing prior shape information about cytoplasm are firmly established, they often yield visually implausible results, as they model shape priors only by limited shape hypotheses about cytoplasm, exploit cytoplasm-level shape priors alone, and impose no shape constraint on the resulting shape of the cytoplasm In this paper, we present an effective shape prior-based approach, called constrained multi-shape evolution, that segments all overlapping cytoplasms in the clump simultaneously by jointly evolving each cytoplasm's shape guided by the modeled shape priors We model local shape priors (cytoplasm-level) by an infinitely large shape hypothesis set which contains all possible shapes of the cytoplasm In the shape evolution, we compensate intensity deficiency for the segmentation by introducing not only the modeled local shape priors but also global shape priors (clump-level) modeled by considering mutual shape constraints of cytoplasms in the clump We also constrain the resulting shape in each evolution to be in the built shape hypothesis set for further reducing implausible segmentation results We evaluated the proposed method in two typical cervical smear datasets, and the extensive experimental results confirm its effectiveness.

The Combination of Anti-CD47 Antibody with CTLA4 Blockade Enhances Anti-Tumor Immunity in Non-Small Cell Lung Cancer via Normalization of Tumor Vasculature and Reprogramming of the Immune Microenvironment.

In solid tumors, the formidable anti-tumor impact resulting from blocking the "don't eat me" signal, arising from CD47-SIRPα interaction, is constrained, especially compared to its efficacy in hematopoietic malignancies. Activating macrophage anti-tumor activity not only necessitates the inhibition of the "don't eat me" signal, but also the activation of the "eat me" (pre-phagocyte) signal. Intriguingly, the cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) antibody (Ab) has been identified to stimulate Fc receptor-mediated active phagocytes in the tumor microenvironment, thereby generating "eat me" signals. This study postulates that concurrently targeting CD47 and CTLA4 could intensify the anti-tumor effects by simultaneously blocking the "don't eat me" signal while triggering the "eat me" signal. The experimental data from this investigation confirm that the combined targeting of CD47 and CTLA4 enhances immunity against solid tumors in LLC cell-transplanted tumor-bearing mice. This effect is achieved by reducing myeloid-derived suppressor cell infiltration while increasing the presence of effector memory CD8+ T cells, NK1.1+ CD8+ T cells, and activated natural killer T cells. Meanwhile, combination therapy also alleviated anemia. Mechanistically, the anti-CD47 Ab is shown to upregulate CTLA4 levels in NSCLC cells by regulating Foxp1. Furthermore, targeting CD47 is demonstrated to promote tumor vascular normalization through the heightened infiltration of CD4+ T cells. These findings suggest that the dual targeting of CD47 and CTLA4 exerts anti-tumor effects by orchestrating the "eat me" and "don't eat me" signals, reshaping the immune microenvironment, and fostering tumor vascular normalization. This combined therapeutic approach emerges as a potent strategy for effectively treating solid tumors.

TRIM9 promotes Müller cell-derived retinal stem cells to differentiate into retinal ganglion cells by regulating Atoh7.

Glaucoma is a multifactorial, irreversible blinding eye disease characterized by a large number of retinal ganglion cell (RGC) deaths. Müller cell-derived retinal stem cells (RSCs) can be induced to differentiate into RGCs under certain conditions. This study aimed to explore the regulatory effect and mechanism of TRIM9 on the differentiation of Müller cell-derived stem cells into RGCs. First, episcleral vein cauterization was used to induce high intraocular pressure (IOP) rat model. Next, Müller cells were isolated from rat retina, identified and induced to dedifferentiate into RSCs. Finally, RSCs were intervened with lentivirus PGC-FU-TRIM9-GFP transfection or siRNA Atoh7 and induced to redifferentiate into RGCs. In vivo, TRIM9 was highly expressed and Müller cells proliferated abnormally in the high IOP rat model. In vitro, S-100, GFAP, vimentin, and GS were positively expressed in Müller cells isolated from rat retina, and the purity of cells was 97.17%. Under the stimulation of cytokines, the proliferative capacity of the cells and the expression of Nestin and Ki67 gradually increased with the prolongation of culture time. Furthermore, RSCs transfected with the lentiviral vector PGC-FU-TRIM9-GFP displayed a striking morphological feature of long neurites. Additionally, there was a remarkable increase in the fluorescence intensity of Brn-3b and Thy1.1, accompanied by elevated mRNA and protein expression levels of Brn-3b, Thy1.1, and Atoh7. After knocking down Atoh7, the effect of TRIM9 on the above indicators was reversed. TRIM9 might promote the differentiation of Müller cells into RGCs by regulating the expression of Atoh7.

Significance of the cGAS-STING Pathway in Health and Disease.

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway plays a significant role in health and disease. In this pathway, cGAS, one of the major cytosolic DNA sensors in mammalian cells, regulates innate immunity and the STING-dependent production of pro-inflammatory cytokines, including type-I interferon. Moreover, the cGAS-STING pathway is integral to other cellular processes, such as cell death, cell senescence, and autophagy. Activation of the cGAS-STING pathway by "self" DNA is also attributed to various infectious diseases and autoimmune or inflammatory conditions. In addition, the cGAS-STING pathway activation functions as a link between innate and adaptive immunity, leading to the inhibition or facilitation of tumorigenesis; therefore, research targeting this pathway can provide novel clues for clinical applications to treat infectious, inflammatory, and autoimmune diseases and even cancer. In this review, we focus on the cGAS-STING pathway and its corresponding cellular and molecular mechanisms in health and disease.

The impact of heterogeneous environmental regulation on high-quality economic development in China: based on the moderating effect of digital finance.

Under the new normal of economic growth, implementing environmental regulation policies and developing digital finance have become essential factors affecting high-quality economic development. This study aims to examine whether environmental regulation has a positive effect on high-quality economic development and what impact digital finance has in the process of environmental regulation affecting high-quality economic development. This study uses the panel data of 30 provinces in China from 2011 to 2019 to measure the high-quality economic development by using the entropy-TOPSIS method based on constructing an indicator system for high-quality economic development. Then, environmental regulations are classified into four categories: economic, command based, legal, and supervised, and digital finance is included in the analysis framework. The impact of heterogeneous environmental regulations on high-quality economic development and the indirect influence mechanism played by digital finance are empirically analyzed. The results show that command-based environmental regulation significantly hinders improving economic development quality. In contrast, supervised environmental regulation plays a significant positive role and can therefore serve as an essential driver of high-quality economic development. In addition, digital finance plays a significant positive moderating role in the influence of environmental regulation on the economy's high-quality development level. After the robustness test, the conclusion is still valid. Further heterogeneity analysis shows that the impact of environmental regulation on high-quality economic development and the moderating effect of digital finance differ across dimensions of economic quality development and have regional heterogeneity. The research findings are conducive to formulating appropriate environmental regulation policies and giving full play to the positive role of digital finance, providing support for promoting high-quality economic development.

Vaccine induced memory CD8+ T cells efficiently prevent viral transmission from the respiratory tract.

Introduction: Mucosal immunization eliciting local T-cell memory has been suggested for improved protection against respiratory infections caused by viral variants evading pre-existing antibodies. However, it remains unclear whether T-cell targeted vaccines suffice for prevention of viral transmission and to which extent local immunity is important in this context. Methods: To study the impact of T-cell vaccination on the course of viral respiratory infection and in particular the capacity to inhibit viral transmission, we used a mouse model involving natural murine parainfluenza infection with a luciferase encoding virus and an adenovirus based nucleoprotein targeting vaccine. Results and discussion: Prior intranasal immunization inducing strong mucosal CD8+ T cell immunity provided an almost immediate shut-down of the incipient infection and completely inhibited contact based viral spreading. If this first line of defense did not operate, as in parentally immunized mice, recirculating T cells participated in accelerated viral control that reduced the intensity of inter-individual transmission. These observations underscore the importance of pursuing the development of mucosal T-cell inducing vaccines for optimal protection of the individual and inhibition of inter-individual transmission (herd immunity), while at the same time explain why induction of a strong systemic T-cell response may still impact viral transmission.

Scalable CNTs/NiCoSe2 Hybrid Films for Flexible All-Solid-State Asymmetric Supercapacitors.

The rapidly developing wearable flexible electronics makes the development of high-performance flexible energy storage devices, such as all-solid-state supercapacitors (SCs), particularly important. Herein, we report the fabrication of CNTs/NiCoSe2 hybrid films on carbon cloth (CC) through a facile co-electrodeposition method based on flexible electrodes for all-solid-state SCs. The NiCoSe2 sheets grown on CNTs uniformly with a diameter of 50-100 nm act as the active materials. The CNTs in the hybrid films act as the scaffold to offer more deposition sites for NiCoSe2 and provide a conductive network to facilitate the transfer of electrons. Moreover, the one-step electrodeposition process avoids the usage of any organic binders. Benefiting from the high intrinsic reactivity and unique 3D architecture, the obtained CNTs/NiCoSe2 electrode delivers high specific capacity (218.1 mA h g-1) and satisfactory durability (over 5000 cycles). Remarkably, the CNTs/NiCoSe2//AC flexible all-solid-state (FASS) ASC provides remarkable energy density (112.2 W h kg-1) within 0-1.7 V and maintains 98.1% of its initial capacity after 10,000 cycles. In addition, this flexible ASC device could be fabricated at a large scale (5 × 6 cm2), and the LED arrays (>3.7 V) can be easily lighted up by three ASCs in series, showing its potential practical application.

Peptidoglycan recognition proteins regulate immune response of Antheraea pernyi in different ways.

Peptidoglycan recognition proteins (PGRPs) are evolutionarily conserved molecules that act in innate immune responses against invading pathogens. Insect PGRPs activate the Toll and/or immune deficiency (IMD) signal transduction pathways. They induce cellular and humoral immune defense reactions that effectively protect insects from invasion of microorganisms. In this study, four cDNA clones encoding PGRPs (ApPGRP-A, ApPGRP-B, ApPGRP-C, ApPGRP-LE) were isolated from the Chinese oak silkworm, Antheraea pernyi. The deduced amino acid sequences of ApPGRP-B and -C share high identity with enzymatically active PGRP proteins and contain the amino acids required for amidase activity. The spatiotemporal expression patterns of ApPGRPs and their response to immune stimulations were determined, and suggest that PGRPs might act as a broad-spectrum pattern recognition protein and participate in the pathway activation system. Here, using an RNA-interference approach, we examined the function of PGRPs in response to immune stimulation. We observed that RNAi-mediated silencing of ApPGRP-A decreased the tested antimicrobial peptides (Attacin, Attacin 2, Ceropin, Gloverin, lysozyme and Lebocin) in response to Enterococcus pernyi challenge. However, reducing the ApPGRP-B, -C mRNA levels led to a strong increase of the AMP genes (except for Lebocin). These results suggest that ApPGRPs are necessary for pathway initiation complex formation and activate AMP generation. Our data also indicated that PGRP-B and -C down-regulate AMPs generation in the immune response.

Synthesis, structure and magnetic properties of two mixed-valence icosanuclear nanocages.

The reactions of 3,3'-bis(5-mercapto-1,2,4-triazole) with Co(ii) and Ni(ii) ions, respectively, gave two nanospheric mixed-valence icosanuclear cage-like complexes [M20L12](SO4)2·6DMF·CH3OH·3H2O (M = Co, 1; Ni, 2) with the in situ generated oxalyldithiosemicarbazide (H4L) as ligand. The eight octahedral M(ii) ions and twelve square-planar M(iii) ions in the two complexes are linked by twelve three-connecting linkers of L4- to build an icosanuclear [MII8MIII12L12]4+ nanocage with an inner cubic MII8 cage core. Their cage skeletons are stable in water. The sulphate anions reside over the cage portals. The magnetic measurements of the two complexes revealed the presence of dominant antiferromagnetic interactions between the metal ions in both complexes.

[Link between sortase A function and cariogenicity of Streptococcus mutans: a preliminary metabolomics analysis].

OBJECTIVE: This study intends to explore the mechanism underlying the support of sortase A (SrtA) of the cariogenicity of Streptococcus mutans (S. mutans). METHODS: We performed a metabonomics study based on ¹H nuclear magnetic resonance spectroscopy (NMR), in which we compared the extracellular metabolites of wild-type S. mutans UA159 with those of its SrtA-deficient strain. Metabolite differences among strains were identified using a combination of principal component analysis and orthogonality partial least square discriminant analysis. RESULTS: Several differences corresponding mostly to unknown metabolites were identified. Some amino acids such as leucine and valine (δ 0.92×10⁻6-1.20×10⁻6), lactic acid ( δ1.28×10⁻6), oxoglutaric acid (δ 3.00×10⁻6), and glycine (δ 3.60×10⁻6) differed among strains. CONCLUSIONS: This work establishes the feasibility of using ¹H NMR-based metabonomics to provide leads for research into molecular factors that promote caries. The database of microbial metabolites should be also improved in further studies.

A pilot study of the metabolomic profiles of saliva from female orthodontic patients with external apical root resorption.

BACKGROUND: Orthodontically induced external apical root resorption (OIEARR) is one of the most severe complications of orthodontic treatment, which is hard to diagnose at early stage by merely radiographic examination. This study aimed to identify salivary metabolic products using unbiased metabolic profiling in order to discover biomarkers that may indicate OIEARR. MATERIALS AND METHODS: Unstimulated saliva samples were analyzed from 19 healthy orthodontic patients with EARR (n=8) and non-EARR (n=11). Metabolite profiling was performed using 1H Nuclear Magnetic Resonance (NMR) spectroscopy. RESULTS: A total of 187 metabolites were found in saliva samples. With supervised partial least squares discriminant analysis and regression analysis, samples from 2 groups were well separated, attributed by a series of metabolites of interest, including butyrate, propane-1,2-diol, α-linolenic acid (Ala), α-glucose, urea, fumarate, formate, guanosine, purine, etc. Indicating the increased inflammatory responses in the periodontal tissues possibly associated with energy metabolism and oxidative stress. CONCLUSIONS: The effective separation capacity of 1H NMR based metabolomics suggested potential feasibility of clinical application in monitoring periodontal and apical condition in orthodontic patients during treatment and make early diagnosis of OIEARR. Metabolites detected in this study need further validation to identify exact biomarkers of OIEARR. Saliva biomarkers may assist in diagnosis and monitoring of this disease.

Isolation and molecular cloning of hepatocyte growth factor from guinea pig (gHGF), and expression of truncated variant of gHGF with improved anti-fibrotic activity in Escherichia coli.

Hepatocyte growth factor (HGF) is an attractive target for anti-fibrotic therapy because it attenuates excessive transforming growth factor-ß1 (TGF-ß1) which plays an important role in hepatic fibrosis. In the study, we reported on the isolation and molecular cloning of the open reading frame (ORF) of guinea pig HGF (gHGF), encoding a protein of 729 amino acids, with an apple-like (hairpin) domain, four kringle domains and a trypsin-like serine protease domain. Moreover, the truncated variant of gHGF (a double mutant of N-terminal hairpin and first kringle domains of gHGF, K132E and G134E, gmNK1) protein fused with His6 tag, the molecular weight of which was about 20.0kDa, which was expressed in Escherichia coli BL21 (DE3) and purified with Ni2+-affinity chromatography. Furthermore, gmNK1 inhibited protein expression levels of fibrosis-related type I collagen (Col I) and α-smooth muscle actin (α-SMA) genes in TGF-ß1-activated HSC-T6 cells and CCl4-induced liver fibrosis in rat. In addition, gmNK1 ameliorated liver morphology and fibrotic responses in fibrosis animal. Taken together, we first reported on the sequence of HGF from guinea pig and determined the anti-fibrotic activity of gmNK1 in hepatic fibrosis, which will be helpful for investigations into the biological roles of gHGF in this important animal model.

Non-Gaussian Systems Control Performance Assessment Based on Rational Entropy.

Control loop Performance Assessment (CPA) plays an important role in system operations. Stochastic statistical CPA index, such as a minimum variance controller (MVC)-based CPA index, is one of the most widely used CPA indices. In this paper, a new minimum entropy controller (MEC)-based CPA method of linear non-Gaussian systems is proposed. In this method, probability density function (PDF) and rational entropy (RE) are respectively used to describe the characteristics and the uncertainty of random variables. To better estimate the performance benchmark, an improved EDA algorithm, which is used to estimate the system parameters and noise PDF, is given. The effectiveness of the proposed method is illustrated through case studies on an ARMAX system.

Upregulation of a Trypsin-Like Serine Protease Gene in Antheraea pernyi (Lepidoptera: Saturniidae) Strains Exposed to Different Pathogens.

Antheraea pernyi Guérin-Méneville is used for silk production and as a food resource. Its infection by exogenous pathogens, including microsporidia, fungi, bacteria, and virus, can lead to silkworm diseases, causing major economic losses. A trypsin-like serine protease gene (TLS) was found in A. pernyi transcriptome data resulting from two different infection experiments. The cDNA sequence of ApTLS was 1,020 bp in length and contained an open reading frame of 774 bp encoding a 257-amino acid protein (GenBank KF779933). The present study investigated the expression patterns of ApTLS after exposure to different pathogens, and in four different A. pernyi strains. Semiquantitative RT-PCR indicated that ApTLS was expressed in all developmental stages and was most expressed in the midgut. Quantitative real-time PCR indicated ApTLS was upregulated in the midgut of A. pernyi exposed to nucleopolyhedrovirus (ApNPV), Nosema pernyi, Enterococcus pernyi, and Beauveria bassiana infections, and the highest gene expression level was found under ApNPV infection. The strain Shenhuang No. 2 presented the lowest infection rate and the highest ApTLS gene expression level when exposed to ApNPV. Thus, ApTLS seems to be involved in innate defense reactions in A. pernyi.

Morphological characterization and HSP70-, IGS-based phylogenetic analysis of two microsporidian parasites isolated from Antheraea pernyi.

Two microsporidian isolates were extracted from single infected egg-laying tussah silk moth (Antheraea pernyi) in Liaoning Province, China. The microsporidia were subsequently grown in silk moth larvae, isolated, and subjected to morphological characterization (by light and transmission electron microscopy) and phylogenetic analysis (based on conserved genes). One type of spore was long-axis-oval in shape, measuring 4.71 × 1.95 µm, and the other type was short-axis-oval, measuring 3.64 × 2.17 µm. These dimensions were markedly different from those reported in the spores of the common microsporidia infecting A. pernyi, namely, Nosema pernyi (4.36 × 1.49 µm). A neighbor-joining phylogenetic tree based on HSP70 indicated that these microsporidia belonged to Nosema species and were closely related with Nosema bombycis and Nosema ceranae. Furthermore, in the phylogenetic tree based on the intergenic spacer (IGS) region, the long-axis-oval isolates were closely related and tended to form a clade away from the short-axis-oval isolates and N. pernyi isolates. The microsporidia isolated from A. pernyi clustered in one group. Nosema bombycis, Nosema spodopterae, and Endoreticulatus spp. appeared to be genetically distant from N. pernyi. The two isolates from A. pernyi fell in the Nosema group, but their spores differed from those of the spores of the common A. pernyi parasite N. pernyi, both in morphological and genetic aspects. The two isolates were designated Nosema sp. Ap (L) and Nosema sp. Ap (S). IGS was found to be informative in ascertaining phylogenetic relationships among species, and even closely related strains, of microsporidia.

Influence of Surface Properties on Adhesion Forces and Attachment of Streptococcus mutans to Zirconia In Vitro.

Zirconia is becoming a prevalent material in dentistry. However, any foreign bodies inserted may provide new niches for the bacteria in oral cavity. The object of this study was to explore the effect of surface properties including surface roughness and hydrophobicity on the adhesion and biofilm formation of Streptococcus mutans (S. mutans) to zirconia. Atomic force microscopy was employed to determine the zirconia surface morphology and the adhesion forces between the S. mutans and zirconia. The results showed that the surface roughness was nanoscale and significantly different among tested groups (P < 0.05): Coarse (23.94 ± 2.52 nm) > Medium (17.00 ± 3.81 nm) > Fine (11.89 ± 1.68 nm). The contact angles of the Coarse group were the highest, followed by the Medium and the Fine groups. Increasing the surface roughness and hydrophobicity resulted in an increase of adhesion forces and early attachment (2 h and 4 h) of S. mutans on the zirconia but no influence on the further development of biofilm (6 h~24 h). Our findings suggest that the surface roughness in nanoscale and hydrophobicity of zirconia had influence on the S. mutans initial adhesion force and early attachment instead of whole stages of biofilm formation.

The Pleiotropic Effects of PPARs on Vascular Cells and Angiogenesis: Implications for Tissue Engineering.

Angiogenesis is a complex process in which capillaries are produced from blood vessels that already exists. Endothelial cells (ECs) and endothelial progenitor cells (EPCs) are pivotal for this process and for the maintenance/restorage of the endothelium. Decreased numbers and dysfunction of these cells have been related to growing cardiovascular risks. Peroxisome-proliferator-activated receptor (PPAR) is a large family of nuclear receptors, characterized by three isotypes: α, ß and γ. Numerous studies have shown that PPAR activation is involved in the pathology of a wide range of cardiovascular diseases and has a role in endothelial function, thrombosis and inflammation, etc., suggesting that PPAR agonists may be good candidates to treat the cardiovascular disease. However, controversial results exist on whether this nuclear receptor is inductive or depressive in the process of angiogenesis. Herein, this review will provide a detailed discussion of the up-to-date investigation of the role of PPARs in angiogenesis, with particular reference to their effects on angiogenesis-related cells--i.e., ECs, EPCs, vascular smooth-muscle cells (VSMCs), macrophages and endometrial cells--and will discuss the current and potential future applications of PPAR activators.

Effect of enamel morphology on nanoscale adhesion forces of streptococcal bacteria : An AFM study.

We explore the influence of enamel surface morphology on nanoscale bacterial adhesion forces. Three dimensional morphology characteristics of enamel slices, which were treated with phosphoric acid (for 0 s, 5 s, 10 s, 20 s, and 30 s), were acquired. Adhesion forces of three initial colonizers (Streptococcus oralis, Streptococcus sanguinis, and Streptococcus mitis) and two cariogenic bacterial strains (Streptococcus mutans and Streptococcus sobrinus) with etched enamel surfaces were determined. Comparison of the forces was made by using bacterial probe method under atomic force microscope (AFM) in adhesion buffer. The results showed that enamel morphology was significantly altered by etching treatment. The roughness, peak-to-valley height, and valley-to-valley width of the depth profile, surface area, and volume increased linearly with acid exposure time, and reached the maximum at 30s, respectively. The adhesion forces of different strains increased accordingly with etching time. Adhesion forces of S. oralis, S. mitis, S. mutans, and S. sobrinus reached the maximum values of 0.81 nN, 0.84 nN, 0.73 nN, and 0.64 nN with enamel treated for 20s, respectively, whereas that of S. sanguinis at 10s (1.28nN), and dropped on coarser enamel surfaces. In conclusion, enamel micro-scale morphology may significantly alter the direct adhesion forces of bacteria. And there may be a threshold roughness for bacterial adhesion on enamel surface.

Analysis of plasma metabolic biomarkers in the development of 4-nitroquinoline-1-oxide-induced oral carcinogenesis in rats.

The aim of the present study was to identify time-dependent changes in the expression of metabolic biomarkers during the various stages of oral carcinogenesis to provide an insight into the sequential mechanism of oral cancer development. An 1H nuclear magnetic resonance (NMR)-based metabolomics approach was used to analyze the blood plasma samples of Sprague-Dawley rats exhibiting various oral lesions induced by the administration of 4-nitroquinoline-1-oxide (4NQO) in drinking water. The 1H NMR spectra were processed by principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) to determine the metabolic differences between the three developmental stages of oral mucosa cancer (health, oral leukoplakia [OLK] and oral squamous cell carcinoma [OSCC]). The variable importance in projection (VIP) score derived from the PLS-DA model was used to screen for important metabolites, whose significance was further verified through analysis of variance (ANOVA). Data from the present study indicated that 4NQO-induced rat oral carcinogenesis produced oral pre-neoplastic and neoplastic lesions and provided an effective model for analyzing sequential changes in the 1H NMR spectra of rat blood plasma. The 1H NMR-based metabolomics approach clearly differentiates between healthy, OLK and OSSC rats in the PCA and PLS-DA models. Furthermore, lactic acid, choline, glucose, proline, valine, isoleucine, aspartic acid and 2-hydroxybutyric acid demonstrated VIP>1 in the PLS-D model and P<0.05 with ANOVA. It was also identified that increases in lactic acid, choline and glucose, and decreases in proline, valine, isoleucine, aspartic acid and 2-hydroxybutyric acid may be relative to the characteristic mechanisms of oral carcinogenesis. Therefore, these plasma metabolites may serve as metabolic biomarkers in oral carcinogenesis and assist in the early diagnosis and preventive treatment of oral cancer.