Rapid conversion of porcine pluripotent stem cells into macrophages with chemically defined conditions.

A renewable source of porcine macrophages derived from pluripotent stem cells (PSCs) would be a valuable alternative to primary porcine alveolar macrophages (PAMs) in the research of host-pathogen interaction mechanisms. We developed an efficient and rapid protocol, within 11 days, to derive macrophages from porcine PSCs (pPSCs). The pPSC-derived macrophages (pPSCdMs) exhibited molecular and functional characteristics of primary macrophages. The pPSCdMs showed macrophage-specific surface protein expression and macrophage-specific transcription factors, similar to PAMs. The pPSCdMs also exhibited the functional characteristics of macrophages, such as endocytosis, phagocytosis, porcine respiratory and reproductive syndrome virus infection and the response to lipopolysaccharide stimulation. Furthermore, we performed transcriptome sequencing of the whole differentiation process to track the fate transitions of porcine PSCs involved in the signaling pathway. The activation of transforming growth factor beta signaling was required for the formation of mesoderm and the inhibition of the transforming growth factor beta signaling pathway at the hematopoietic endothelium stage could enhance the fate transformation of hematopoiesis. In summary, we developed an efficient and rapid protocol to generate pPSCdMs that showed aspects of functional maturity comparable with PAMs. pPSCdMs could provide a broad prospect for the platforms of host-pathogen interaction mechanisms.

In Situ Visualization of RNA-Specific Sialylation on Living Cell Membranes to Explore N-Glycosylation Sites.

The small RNAs on living cell membranes were recently found to be N-glycosylated and terminated with sialic acids, although the glycosylation sites and potential functions remain unclear. Herein, we designed a second-generation hierarchical coding strategy (HieCo 2) for in situ visualization of cell surface RNA-specific sialylation. After covalently binding DNA codes to sialic acids and then binding a DNA code to a target RNA via sequence specificity, cascade decoding processes were performed with subsequent signal amplification that enabled sensitive in situ visualization of low-abundance Y5 RNA-specific sialic acids on living cell membranes. The proposed strategy unveils the number of glycosylation sites on a single RNA and reveals the binding preference of glycosylated RNAs to different sialic acid binding-immunoglobulin lectin-type receptors, demonstrating a new route for exploration of the glycosylated RNA-related biological and pathological processes.

Associations between particulate matter exposure during pregnancy and executive function of toddlers in a prospective cohort study.

BACKGROUND: Exposure to particulate matter (PM) has been found to be associated with impaired cognitive function. However, limited evidence is available on the relationship between PM exposure in the prenatal period and toddler executive function (EF), and the potential influence of breastfeeding. METHODS: The study included 1106 mother-toddler pairs recruited between 2015 and 2019. We assessed mothers' PM1, PM2.5, and PM10 prenatal exposure with a satellite-based dataset at a 1 × 1 km spatial resolution and assigned to participants based on residential addresses. Toddler EF was measured using the Behavior Rating Inventory of Executive Function for Preschoolers (BRIEF-P) questionnaire, higher BRIEF-P scores indicated poorer EF in toddlers. We determined the associations of PM exposure during pregnancy with BRIEF-P scores using multiple linear regression models. RESULTS: In the first trimester, a 10 µg/m3 increase of PM was associated with 1.49 (95% confidence interval [CI]: 0.14-2.83; PM1), 0.68 (95% CI: 0.10-1.26; PM2.5), and 0.63 (95% CI: 0.07-1.20; PM10) elevated toddler global executive composite index scores, respectively. In the stratified analysis, a 10 µg/m3 increase in first trimester PM1 exposure was related to 0.54 (95% CI: 0.19-0.89) higher inhibition scores in toddlers who received complementary breastfeeding for less than six months and -0.15 (95% CI: 0.81-0.51) higher inhibition scores in toddlers who received complementary breastfeeding for six months or more (P for interaction: 0.046). Additionally, a 10 µg/m3 increment in first trimester PM1 exposure was related to 0.36 (95% CI: 0.13-0.59) higher emotional control scores in toddlers who received breastfeeding for less than 12 months and -0.54 (95% CI: 1.25-0.18) higher inhibition scores in toddlers who received breastfeeding for no less than 12 months (P for interaction: 0.043). CONCLUSIONS: PM exposure during the first trimester, especially PM1, has been linked to lower toddler EF performance in toddlers; feeding with breast milk may be a potential protective measure.

Aitongping patch could alleviate cancer pain via suppressing microglia activation and modulating the miR-150-5p/CXCL12 signaling.

PURPOSE: We aimed to investigate the pharmacological effects and mechanisms of the Aitongping formula for treating cancer pain. METHODS: We enrolled 60 cancer patients with Numeric Rating Scale above 4 and grouped them randomly as a Control group (N = 30) and a Patch group (N = 30). We also established bone cancer mice models via tumor implantation. And the animal groups were established as a Sham group, a tumor cell implantation (TCI) group, a TCI + Patch group, and a Patch group. RESULTS: After the validation of successful tumor implantation, we identified candidate miRNAs and genes that were dysregulated in TCI mice and compared their expressions between different mice groups. We also observed the effect of Aitongping patch in vitro in mice primary microglia. The time to disease progression and cancer stability were prolonged by Aitongping patch in cancer patients. And the daily morphine dose was lower, and patients' quality of life was improved in the Patch group. Moreover, Aitongping patch alleviated cancer pain and inhibited microglia activation after the successful implantation of bone tumor in TCI mice. We also observed the dysregulation of miR-150-5p and chemokine CXC motif ligand 12 (CXCL12) mRNA in TCI mice. And CXCL12 was found to be targeted by miR-150-5p. Aitongping patch was found to upregulate miR-150-5p and downregulate CXCL12 in vivo and in vitro. CONCLUSION: Aitongping patch could alleviate cancer pain via suppressing microglia activation, and the downregulation of miR-150-5p, as well as the upregulation of CXCL12 mRNA and protein, induced by tumor implantation or lipopolysaccharide stimulation, was restored by Aitongping treatment.

Ultra-Galactocation to Sialic Acid on Tumor Cells with A Penta-Functional Dendritic Probe for Enhanced Immune-Killing.

Glycans on tumor cell surface have significant impacts in the immune-killing process. Here an ultra-galactocation to sialic acid (Sia) strategy is designed to hugely introduce galactose (Gal) to Sia and on tumor cells in vivo by using a penta-functional dendritic probe (Den@5F), which efficiently enhances the immune-killing of tumor cells. The Den@5F contains five different kinds of functional groups, including Gal, Cy5, amino, phenylboronic acid (PBA) and 4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy) butanoate (mNB), which can be conveniently prepared through a two-step reaction. After injecting into the tumor-bearing mouse, Den@5F can efficiently block Sia through the specific recognition between PBA and Sia on tumor cells and hugely introduce Gal through the subsequent photo-crosslinking between mNB and amino groups to multiply conjugate excessive Den@5Fs. The comprehensively blocked Sia can prevent the immune escape, and the hugely introduced Gal can promote the immune stimulation of the immune cells, which lead to an efficient enhancement of the immune-killing. The proposed strategy provides a significant and promising tool to promote the clinical immunotherapy of tumor.

Signal-On Mass Spectrometric Biosensing of Multiplex Matrix Metalloproteinases with a Phospholipid-Structured Mass-Encoded Microplate.

The detection of matrix metalloproteinases (MMPs) is of great importance for diagnosis and staging of cancer. This work proposed a signal-on mass spectrometric biosensing strategy with a phospholipid-structured mass-encoded microplate for assessment of multiplex MMP activities. The designed substrate and internal standard peptides were subsequently labeled with the reagents of isobaric tags for relative and absolute quantification (iTRAQ), and DSPE-PEG(2000)maleimide was embedded on the surface of a 96-well glass bottom plate to fabricate the phospholipid-structured mass-encoded microplate, which offered a simulated environment of the extracellular space for enzyme reactions between MMPs and the substrates. The strategy achieved multiplex MMP activity assays by dropping the sample in the well for enzyme cleavages, followed by adding trypsin to release the coding regions for ultrahigh performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) analysis. The peak area ratios of released coding regions and their respective internal standard (IS) peptides exhibited satisfied linear ranges of 0.05-50, 0.1-250, and 0.1-100 ng mL-1 with the detection limits of 0.017, 0.046, and 0.032 ng mL-1 for MMP-2, MMP-7, and MMP-3, respectively. The proposed strategy demonstrated good practicability in inhibition analysis and detections of multiplex MMP activities in serum samples. It is of great potential for clinical applications and can be expanded for multiplex enzyme assays.

Exploration of molecular mechanism underlying protective effect of astragaloside IV against radiation-induced lung injury by suppressing ferroptosis.

In this study, we aimed to investigate the pharmacological effects and underlying mechanisms of astragaloside IV (AS IV) against radiation-induced lung injury. We established experimental models of radiation-induced lung injury and observed the effect of AS IV on cell viability, cell death, inflammatory responses and ferroptosis. Accordingly, we found that AS IV restored the suppressed cell viability and promoted cell death induced by X-ray irradiation. Moreover, radiation-induced up-regulation of lactate dehydrogenase (LDH) release, ferroptosis, reactive oxygen species (ROS) and inflammatory responses were also restored by AS IV in a dose-dependent manner. Besides, in radiation-induced lung injury C57BL/6 mice, AS IV evidently alleviated lung injury and promoted the survival rate of lung-injured mice. And the ferroptosis level in mice lung tissues were also alleviated by the administration of AS IV in a dose-dependent manner. As a conclusion, by comparing the changes of ferroptosis, ROS and inflammatory responses in the experimental models, we validated that AS IV could inhibit inflammatory responses and cell injury in the treatment of radiation-induced lung injury by suppressing ferroptosis. This finding not only find potentially effective treatments to mitigate radiation-induced lung injury, but also provides supporting evidence for clinical application of AS IV to improve the management of radiation-treated patients and minimize the associated lung complications or other adverse effects. Moreover, as inflammation and ROS are key contributors to tissue damage in various diseases, our study suggested the potential application of AS IV in the treatments for other diseases.

Biomimetic Nanoparticles Loaded with Ulinastatin for the Targeted Treatment of Acute Pancreatitis.

Ulinastatin is commonly used in the clinic to treat acute pancreatitis (AP), but its therapeutic effect was limited by the presence of the blood-pancreas barrier (BPB) and low specificity. Here, we prepared a macrophage biomimetic nanoparticle (MU) that delivered ulinastatin to address the above issues. Macrophage membrane was used as a shell for a mixture of PEG-PLGA and ulinastatin. It was found that MU showed good stability and biocompatibility in vitro and in vivo. According to in vivo fluorescence imaging, MU displayed a great inflammation targeting effect both in a subcutaneous inflammation model and in situ pancreatitis mouse model, which was ascribed to the presence of adhesion proteins. In vitro and in vivo results demonstrated that MU have a superior AP treatment effect by inhibiting pro-inflammatory factors and keeping cells viability. It was suggested the MU could provide a new strategy for targeted AP treatment.

Fluorine-doped BiVO4 photocatalyst: Preferential cleavage of C-N bond for green degradation of glyphosate.

With increasing concerns on the environment and human health, the degradation of glyphosate through the formation of less toxic intermediates is of great importance. Among the developed methods for the degradation of glyphosate, photodegradation is a clean and efficient strategy. In this work, we report a new photocatalyst by doping F ion on BiVO4 that can efficiently degrade glyphosate and reduce the toxic emissions of aminomethylphosphonic acid (AMPA) through the selective (P)-C-N cleavage in comparison of BiVO4 catalyst. The results demonstrate that the best suppression of AMPA formation was achieved by the catalyst of 0.3F@BiVO4 at pH = 9 (AMPA formation below 10%). In situ attenuated total reflectance Fourier transforms infrared (ATR-FTIR) spectroscopy indicates that the adsorption sites of glyphosate on BiVO4 and 0.3F@BiVO4 are altered due to the difference in electrostatic interactions. Such an absorption alteration leads to the preferential cleavage of the C-N bond on the N-C-P skeleton, thereby inhibiting the formation of toxic AMPA. These results improve our understanding of the photodegradation process of glyphosate catalyzed by BiVO4-based catalysts and pave a safe way for abiotic degradation of glyphosate.

Mass-Encoded Suspension Array for Multiplex Detection of Matrix Metalloproteinase Activities.

This work designed a mass spectrometric biosensing strategy for the multiplex detection of matrix metalloproteinases (MMPs) with a mass-encoded suspension array. This array was fabricated as multiplex sensing probes by functionalizing magnetic beads with MMP-specific peptide-isobaric tags for relative and absolute quantification (iTRAQ) conjugates, which contained a hexahistidine tag for surface binding, a substrate region for MMP cleavage, and a coding region for the specific MMP. The integration of the multiplex coding ability of iTRAQ with ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and the proteolysis method for peptide digestion endowed the biosensing method with high throughput and ultrahigh sensitivity. This strategy could be conveniently performed by mixing the sample and the suspension array for enzymatic reactions and then digesting the uncleaved peptides with trypsin to release the coding regions for UPLC-MS/MS analysis. With MMP-2 and MMP-7 as analytes, the relative changes of peak area ratios of coding regions showed good linear responses in the ranges of 0.2-100 and 0.5-400 ng mL-1, with detection limits of 0.064 and 0.17 ng mL-1, respectively. The analysis of MMP activity in serum samples and its change responding to inhibitors demonstrated the specificity, practicability, and expansibility of the proposed strategy. This work paves a new avenue for the activity assays of multiplex enzymes and promotes the development of mass spectrometric biosensing.

Laparoscopic in Situ Anatomical Mesohepatectomy for Solitary Massive HCC Using Combined Intrafascial and Extrafascial Approaches With Indocyanine Green Navigation (with Video).

BACKGROUND: Laparoscopic anatomic mesohepatectomy for patients with hepatocellular carcinoma (HCC) remains technically challenging, especially for those with a massive tumor larger than 10 cm. METHODS: In this study, a 65-year-old man with a 13 × 10-cm2 solitary liver tumor located at segments 4, 5, and 8 underwent laparoscopic mesohepatectomy. To reduce the possibility of releasing cancer cells from the primary tumor, the in situ resection strategy for tumor removal was implemented. The intrafascial approach was used to dissect the right Glissonean pedicle, to transect the right anterior hepatic artery, and to ligate the right anterior portal vein. The extrafascial and transfissural approach was performed along the umbilical fissure to transect the Glissonean pedicle of segment 4. Indocyanine green (ICG) then was applied using "reverse staining" to visualize the resection extent and the right posterior hepatic duct (RPHD). During parenchymal resection, the right anterior Glissonean pedicle was adequately exposed and transected via the extrafascial approach above the plane of the RPHD. Finally, the right coronary ligament was dissected, and the tumor was removed. RESULTS: The operation was completed in 360 min, with a blood loss of 200 mL. The histopathologic diagnosis indicated a moderately differentiated HCC. The patient was discharged on postoperative day 8 without any complications. CONCLUSION: Laparoscopic in situ anatomic mesohepatectomy using combined intra- and extrafascial approaches with ICG navigation may be feasible for patients with a centrally located solitary massive HCC.

Augmented reality navigation facilitates laparoscopic removal of foreign body in the pancreas that cause chronic complications.

BACKGROUND: Foreign bodies that enter the pancreas and cause chronic complications cannot be removed by endoscopy. Surgical removal is necessary but also challenging. The development of augmented reality navigation has made it possible to accurate intraoperative navigation in laparoscopic surgery. METHODS: A 37-year-old female had epigastric pain for 3 months and her abdominal CT showed a linear high-density shadow in her pancreas along with chronic pancreatitis. Three-dimensional models of the liver, pancreas, stomach, blood vessels, and foreign body were created based on CT images. Gastroptosis was found in the three-dimensional models, so surgical approach was adapted to open the hepatogastric ligament to reach the pancreas. After 2-3 s of video images were captured by 3D laparoscopy, a three-dimensional dense stereo-reconstruction method was used to obtain the surface model of pancreas, stomach, and blood vessels. The Globally Optimal Iterative Closest Point method was used to obtain a spatial transformation matrix between the preoperative CT image space and the intraoperative laparoscopic space. Under augmented reality navigation guidance, the position and location of the foreign body were displayed on the surface of the pancreas. Then intraoperative ultrasound was used for further verification and to quickly and easily confirm the surgical entrance. After minimal dissection and removal of the pancreatic parenchyma, the foreign body was removed completely. RESULTS: The operation time was 60 min, the estimated blood loss was 10 ml. The foreign body was identified as a 3-cm-long fishbone. The patient recovered without complications and was discharged on the third postoperative day. CONCLUSION: Because it enables direct visual navigation via simple operation, ARN facilitates the laparoscopic removal of foreign bodies in the pancreas with accurate and rapid positioning and minimal damage.

HTLV screening of blood donors using chemiluminescence immunoassay in three major provincial blood centers of China.

BACKGROUND: Human T-cell lymphotropic virus (HTLV) remains a major safety concern for blood supplies. Despite many HTLV positive cases being reported in southeastern China, the detection of HTLV has not been prioritized in routine blood screening. Additionally, data on the prevalence of HTLV infection among blood donors is also limited. The objective of this study was to investigate the prevalence of HTLV among blood donors in three Chinese provinces through their representative blood centers, to evaluate the feasibility of chemiluminescence immunoassay (CLIA) for blood screening. METHODS: From November 2018 to March 2019, blood plasma samples were collected from Hebei, Changsha, and Shenzhen blood centers and were screened for the HTLV-1/2 antibody using a CLIA and enzyme-linked immunosorbent assay (ELISA). This was followed by confirmatory tests using INNO-LIA HTLV I/II. RESULTS: A total of 59,929 blood donations were collected and screened for HTLV-1/2. The reactive rate of CLIA and ELISA among donations in the Shenzhen blood center (0.0943%, 27/28,621) was higher than Hebei (0.0248%, 4/16,144), and Changsha (0.0198%, 3/15,164) (p < 0.05). After confirmation, 3 samples were confirmed as indeterminate for HTLV antibodies, and only one sample from the Shenzhen blood center was confirmed as HTLV-1. The overall prevalence of HTLV-1/2 was 1.67 per 100,000 (1/59,929). The HTLV-infected blood came from a 32-year-old first-time female donor with a high school degree, who belonged to the SHE ethnic minority and was born in the Fujian province. CONCLUSIONS: In summary, the overall prevalence of HTLV-1/2 among blood donors in the three blood centers in China remains relatively low. However, blood donations with positive or indeterminate results for HTLV antibodies reminded us of the importance of HTLV screening among blood donors in China.

In Situ Cellular Glycan Analysis.

Glycan decorates all mammalian cell surfaces through glycosylation, which is one of the most important post-modifications of proteins. Glycans mediate a wide variety of biological processes, including cell growth and differentiation, cell-cell communication, immune response, pathogen interaction, and intracellular signaling events. Besides, tumor cells aberrantly express distinct sets of glycans, which can indicate different tumor onsets and progression processes. Thus, analysis of cellular glycans may contribute to understanding of glycan-related biological processes and correlation of glycan patterns with disease states for clinical diagnosis and treatment. Although proteomics and glycomics have included great efforts for in vitro study of glycan structures and functions using lysis samples of cells or tissues, they cannot offer real-time qualitative or quantitative information, especially spatial distribution, of glycans on/in intact cells, which is important to the revelation of glycan-related biological events. Moreover, the complex lysis and separation procedures may bring unpredictable loss of glycan information. Focusing on the great urgency for in situ analysis of cellular glycans, our group developed a series of methods for in situ analysis of cellular glycans in the past 10 years. By construction of electrochemical glycan-recognizable probes, glycans on the cell surface can be quantified by direct or competitive electrochemical detection. Using multichannel electrodes or encoded lectin probes, multiple glycans on the cell surface can be dynamically monitored simultaneously. Through design of functional nanoprobes, the cell surface protein-specific glycans and intracellular glycan-related enzymes can be visualized by fluorescence or Raman imaging. Besides, some biological enzymes-based methods have been developed for remodeling or imaging of protein-specific glycans and other types of glycoconjugates, such as gangliosides. Through tracing the changes of glycan expression induced by drugs or gene interference, some glycan-related biological processes have been deduced or proved, demonstrating the reliability and practicability of the developed methods. This Account surveys the key technologies developed in this area, along with the discussion on the shortages of current methodology as well as the possible strategies to overcome those shortages. The future trend in this topic is also discussed. It is expected that this Account can provide a versatile arsenal for chemical and biological researchers to unravel the complex mechanisms involved in glycan-related biological processes and light new beacons in tumor diagnosis and treatment.

Fluorescent visual quantitation of cell-secreted sialoglycoconjugates by chemoselective recognition and hybridization chain reaction.

Sialic acid (SA), usually located at the termini of glycan chains, is one of the most important monosaccharide blocks for glycosylation of proteins. The expression level of sialoglycoconjugates (SiaGCs) in cellular secretome is of great significance in diagnosis of tumor malignancy. This work developed a fluorescent visual method for the detection of SiaGCs secreted from living cells by a boronic acid modified chip based chemoselective recognition and hybridization chain reaction. The cell-secreted SiaGCs, which were labeled with the azide group through a metabolic labeling technique during cell culture, were captured by the chip through chemoselective recognition of boronic acid toward SA. After further conjugating the azide group with an alkyne modified DNA probe, the captured SiaGCs could be conveniently endowed with the amplified fluorescent signal through a hybridization chain reaction of a pair of dye-labeled DNA hairpins, which led to a quantitative imaging method for detection of SiaGCs. The average amount of metabolically labeled SiaGCs secreted from a single HeLa cell and MCF-7 cell was 2.18 × 10-17 and 3.98 × 10-17 mol, respectively. The proposed method could be utilized to monitor the variation of the secreted SiaGCs during drug treatment, providing a useful tool for investigating the glycosylation and glycan-related biological processes.

Functional Dual-Color Indicator To Achieve in Situ Visualization of Intracellular Glycosylation.

A functional dual-color indicator is designed for in situ visualization of intracellular glycosylation. Using O-GlcNAcylation as model, the indicator is constructed on a poly-GlcNAc-coated gold nanoparticle (AuNP) by assembling dye labeled lectin (FSWGA) and then another dye-labeled GlcNAc (FGlcNAc) through the two opposite subunits of FSWGA. These dyes possess negligible overlapping emission and can be quenched by AuNP. In the presence of intracellular dissociated GlcNAc residue and O-GlcNAcylated proteins, the assembled FGlcNAc and the conjugate of FSWGA with FGlcNAc are released from AuNP through the dynamic competitive conjugation, which lights up the fluorescence of two dyes, respectively, and provides a simple technique for simultaneously monitoring the level of O-GlcNAcylated proteins and the total amount of GlcNAc groups in living cells. The practicality of the protocol for visually monitoring the biological pathway between intracellular O-GlcNAcylation and cell surface differentiation-related proteins demonstrates a convenient and powerful tool for research of glycosylation equilibrium and related biological processes.

Quantitative Screening of Cell-Surface Gangliosides by Nondestructive Extraction and Hydrophobic Collection.

A screening strategy involving designed extractors and collectors was used for the nondestructive quantitation of gangliosides on cell surfaces. The extractors were constructed by functionalizing maleimide silica bubbles with a DNA probe, which contains an endonuclease cleavage site and a boronic acid end to extract cell-surface sialic acid-containing compounds through simple centrifugation. After the extractors containing the extracted compounds were incubated with endonuclease, the released oligonucleotide-gangliosides were selectively collected by silanized collector bubbles through hydrophobic interactions. The in vitro fluorescent signals from the collectors were used for the quantitation of cell-surface gangliosides. By combining with sialidase cleavage, a protocol for the identification of ganglioside subtypes was developed. The successful monitoring of the regeneration of cell-surface gangliosides demonstrates the potential of this strategy in probing related biological processes.

Urine Metabonomics Reveals Early Biomarkers in Diabetic Cognitive Dysfunction.

Recently, increasing attention has been paid to diabetic encephalopathy, which is a frequent diabetic complication and affects nearly 30% of diabetics. Because cognitive dysfunction from diabetic encephalopathy might develop into irreversible dementia, early diagnosis and detection of this disease is of great significance for its prevention and treatment. This study is to investigate the early specific metabolites biomarkers in urine prior to the onset of diabetic cognitive dysfunction (DCD) by using metabolomics technology. An ultra-high performance liquid-chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-Q/TOF-MS) platform was used to analyze the urine samples from diabetic mice that were associated with mild cognitive impairment (MCI) and nonassociated with MCI in the stage of diabetes (prior to the onset of DCD). We then screened and validated the early biomarkers using OPLS-DA model and support vector machine (SVM) method. Following multivariate statistical and integration analysis, we found that seven metabolites could be accepted as early biomarkers of DCD, and the SVM results showed that the prediction accuracy is as high as 91.66%. The identities of four biomarkers were determined by mass spectrometry. The identified biomarkers were largely involved in nicotinate and nicotinamide metabolism, glutathione metabolism, tryptophan metabolism, and sphingolipid metabolism. The present study first revealed reliable biomarkers for early diagnosis of DCD. It provides new insight and strategy for the early diagnosis and treatment of DCD.

Polyadenine-Modulated DNA Conformation Monitored by Surface-Enhanced Raman Scattering (SERS) on Multibranched Gold Nanoparticles and Its Sensing Application.

This work proposes a facile way to modulate the conformation of DNA from the "Lie-Down" to the "Stand-Up" conformation on the surface of multibranched gold nanoparticles (AuNPs). This is realized by regulating the length of polyadenine (polyA) linked to the DNA sequence and/or the hybridization of this sequence with the target DNA, and can be monitored by the Raman signal owing to the excellent performance of multibranched AuNPs (AuNSs) as a surface-enhanced Raman scattering (SERS) substrate and the distance change between the Raman reporter and the substrate. The probable mechanism, which depends on the repulsion of polyA from the sequence and the tip assembly, has also been probed through theoretical simulation using the finite difference time domain method. By virtue of this strategy, a conformation-transformation-based DNA@AuNS sensor is constructed for the identification of a specific oligonucleotide, which has been used for the detection of DNA sequences associated with Severe Acute Respiratory Syndrome (SARS). This strategy leads to a novel sensing platform with good extendibility for DNA analysis, and provides a powerful protocol for facilitating the cognition of DNA conformation on metal surfaces.

The auxin transporter, OsAUX1, is involved in primary root and root hair elongation and in Cd stress responses in rice (Oryza sativa L.).

Auxin and cadmium (Cd) stress play critical roles during root development. There are only a few reports on the mechanisms by which Cd stress influences auxin homeostasis and affects primary root (PR) and lateral root (LR) development, and almost nothing is known about how auxin and Cd interfere with root hair (RH) development. Here, we characterize rice osaux1 mutants that have a longer PR and shorter RHs in hydroponic culture, and that are more sensitive to Cd stress compared to wild-type (Dongjin). OsAUX1 expression in root hair cells is different from that of its paralogous gene, AtAUX1, which is expressed in non-hair cells. However, OsAUX1, like AtAUX1, localizes at the plasma membrane and appears to function as an auxin tranporter. Decreased auxin distribution and contents in the osaux1 mutant result in reduction of OsCyCB1;1 expression and shortened PRs, LRs and RHs under Cd stress, but may be rescued by treatment with the membrane-permeable auxin 1-naphthalene acetic acid. Treatment with the auxin transport inhibitors 1-naphthoxyacetic acid and N-1-naphthylphthalamic acid increased the Cd sensitivity of WT rice. Cd contents in the osaux1 mutant were not altered, but reactive oxygen species-mediated damage was enhanced, further increasing the sensitivity of the osaux1 mutant to Cd stress. Taken together, our results indicate that OsAUX1 plays an important role in root development and in responses to Cd stress.