JAM3: A prognostic biomarker for bladder cancer via epithelial­mesenchymal transition regulation

Understanding the intricate relationship between prognosis, immune function, and molecular markers in bladder cancer (BC) demands sophisticated analytical methods. To identify novel biomarkers for predicting prognosis and immune function in BC patients, we combined weighted gene co-expression network analysis (WGCNA) and least absolute shrinkage and selection operator (LASSO) regression analysis. This was conducted using data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Ultimately, we screened the junctional adhesion molecule 3 (JAM3) as an independent risk factor in BC. High levels of JAM3 were linked to adverse clinical parameters, such as higher T and N stages. Additionally, a JAM3-based nomogram model accurately predicted 1-, 3- and 5-year survival rates of BC patients, indicating potential clinical utility. Functional enrichment analysis revealed that high JAM3 expression activated the calcium signaling pathway, the extracellular matrix (ECM)-receptor interaction, and the PI3K-Akt signaling pathway, and was positively correlated with genes associated with epithelial­mesenchymal transition (EMT). Subsequently, we found that overexpression of JAM3 promoted the migration and invasion abilities in BC cells, regulating the expression levels of N-Cadherin, matrix metallopeptidase 2 (MMP2), and Claudin-1 thereby promoting EMT levels. Additionally, we showed that JAM3 was negatively correlated with anti-tumor immune cells such as CD8+T cells, while positively correlated with pro-tumor immune cells such as M2 macrophages, suggesting its involvement in immune cell infiltration. The immune checkpoint CD200 also showed a positive correlation with JAM3. Our findings revealed that elevated JAM3 levels are predictive of poor prognosis and immune cell infiltration in BC patients by regulating the EMT process.

A new immune-related gene signature predicts the prognosis and immune escape of bladder cancer.

BACKGROUND: The biological roles of immune-related genes (IRGs) in bladder cancer (BC) need to be further elucidated. OBJECTIVE: To elucidate the predictive value of IRGs for prognosis and immune escape in BC. METHODS: We comprehensively analyzed the transcriptomic and clinical information of 430 cases, including 19 normal and 411 BC patients from the TCGA database, and verified 165 BC cases in the GSE13507 dataset. The risk model was constructed based on IRGs by applying LASSO Cox regression and exploring the relationship between the risk score and prognosis, gene mutations, and immune escape in BC patients. RESULTS: We identified 4 survival-related genes (PSMC1, RAC3, ROBO2 and ITGB3) among 6,196 IRGs in both the TCGA and GES13507 datasets,, which were used to establish a gene risk model by applying LASSO Cox regression. The results showed that the high-risk (HR) group was closely associated with poor survival or advanced pathological stage of BC. Furthermore, the risk score was found to be an independent risk factor for prognosis of BC patients. In addition, high-risk individuals showed a greater prevalence of TP53 mutations lower CD8+ T-cell and NK cell infiltration, higher Treg cell infiltration, higher expression of PD-L1, and higher immune exclusion scores than those in the low-risk (LR) group. Finally, the experimental verification shows that the model construction gene, especially PMSC1, plays an important role in the growth and metastasis of bladder cancer. CONCLUSIONS: These evidences revealed the vital role of IRGs in predicting prognosis, TP53 mutation and immune escape in BC patients.

Comprehensive analysis of integrin αvß3/α6ß1 in prognosis and immune escape of prostate cancer.

Integrin αvß3/α6ß1 are crucial in the transduction of intercellular cancer information, while their roles in prostate cancer (PCa) remain poorly understood. Here, we systematically analyzed the transcriptome, single nucleotide polymorphisms (SNPs) and clinical data of 495 PCa patients from the TCGA database and verified them in 220 GEO patients, and qPCR was used to validate the expression of the model genes in our patients. First, we found that integrin αvß3/α6ß1 was negatively correlated with most immune cell infiltration and immune functions and closely associated with poor survival in TCGA patients. Then, we divided these patients into two groups according to the expression level of αvß3/α6ß1, intersected differentially expressed genes of the two groups with the GEO dataset and identified eight biochemical recurrence-related genes (BRGs), and these genes were verified by qPCR in our patients. Next, these BRGs were used to construct a prognostic risk model by applying LASSO Cox regression. We found that the high-risk (HR) group showed poorer OS, PFS, biochemical recurrence and clinical characteristics than the low-risk (LR) group. In addition, the HR group was mainly enriched in the cell cycle pathway and had a higher TP53 mutation rate than the LR group. More importantly, lower immune cell infiltration and immune function, higher expression of PD-L1, PD-1, and CTLA4, and higher immune exclusion scores were identified in the HR group, suggesting a higher possibility of immune escape. These findings suggested the key role of integrin αvß3/α6ß1 in predicting prognosis, TP53 mutation and immune escape in PCa.

An ultrafast phototrigger of the Trp5CN-Trp motif in a ß-hairpin peptide.

Phototriggers are useful molecular tools to initiate reactions in enzymes by light for the purpose of photoenzymatic design and mechanistic investigations. Here, we incorporated the non-natural amino acid 5-cyanotryptophan (W5CN) in a polypeptide scaffold and resolved the photochemical reaction of the W5CN-W motif using femtosecond transient UV/Vis and mid-IR spectroscopy. We identified a marker band of ∼2037 cm-1 from the CN stretch of the electron transfer intermediate W5CN·- in the transient IR measurement and found UV/Vis spectroscopic evidence for the W·+ radical at 580 nm. Through kinetic analysis, we characterized that the charge separation between the excited W5CN and W occurs in 253 ps, with a charge-recombination lifetime of 862 ps. Our study highlights the potential use of the W5CN-W pair as an ultrafast phototrigger to initiate reactions in enzymes that are not light-sensitive, making downstream reactions accessible to femtosecond spectroscopic detection.

Prognostic role of iodine values for gastric cancer after neoadjuvant chemotherapy: a strong independent prognostic factor.

PURPOSE We aimed to systematically explore the value of iodine values calculated from dual-energy computed tomography (DECT) as potential prognostic factors for locally advanced gastric cancer (LAGC) patients undergoing neoadjuvant chemotherapy (NAC). METHODS Eighty-five LAGC patients were examined using DECT before and after NAC and were divided into responders and non-responders based on the tumor regression grade (TRG). The iodine values, including portal- and delayed-phase iodine uptake (IU-p and IU-d, mg/ml) and total iodine uptake (TIU-p and TIU-d, mg) were acquired. Correlations between the reduction ratios of iodine values and TRG were analyzed. The diagnostic performance of parameters for differentiating responders from non-responders was calculated. Kaplan-Meier method was used for survival analysis. RESULTS The reduction ratios of total iodine uptake (%△TIU-p and %△TIU-d) were significantly correlated with TRG (p < 0.001). The ypN stage, %△TIU-p and %△TIU-d were significant factors influencing PFS (p < 0.050). A value of %△TIU-d≤62.19% was associated with negative prognosis [relative risk (RR):2.103; P = 0.021], as was ypN stage (RR:4.250; p = 0.003). CONCLUSION Iodine values (especially the TIU) are noninvasive quantitative parameters that are potentially helpful for evaluating the treatment response and survival prognosis of LAGC after NAC. %△TIU-d represents a strong independent prognostic factor, increasing preoperative risk assessment performance.

Quinoline-Based Photolabile Protection Strategy Facilitates Efficient Protein Assembly.

Native chemical ligation (NCL) provides a powerful solution to assemble proteins with precise chemical features, which enables a detailed investigation of the protein structure-function relationship. As an extension to NCL, the discovery of desulfurization and expressed protein ligation (EPL) techniques has greatly expanded the efficient access to large or challenging protein sequences via chemical ligations. Despite its superior reliability, the NCL-desulfurization protocol requires orthogonal protection strategies to allow selective desulfurization in the presence of native Cys, which is crucial to its synthetic application. In contrast to traditional thiol protecting groups, photolabile protecting groups (PPGs), which are removed upon irradiation, simplify protein assembly and therefore provide minimal perturbation to the peptide scaffold. However, current PPG strategies are mainly limited to nitro-benzyl derivatives, which are incompatible with NCL-desulfurization. Herein, we present for the first time that quinoline-based PPG for cysteine can facilitate various ligation strategies, including iterative NCL and EPL-desulfurization methods. 7-(Piperazin-1-yl)-2-(methyl)quinolinyl (PPZQ) caging of multiple cysteine residues within the protein sequence can be readily introduced via late-stage modification, while the traceless removal of PPZQ is highly efficient via photolysis in an aqueous buffer. In addition, the PPZQ group is compatible with radical desulfurization. The efficiency of this strategy has been highlighted by the synthesis of γ-synuclein and phosphorylated cystatin-S via one-pot iterative ligation and EPL-desulfurization methods. Besides, successful sextuple protection and deprotection of the expressed Interleukin-34 fragment demonstrate the great potential of this strategy in protein caging/uncaging investigations.

Fluid-Attenuated Inversion Recovery Vascular Hyperintensities in Transient Ischemic Attack within the Anterior Circulation.

PURPOSE: The aim of the present study was to evaluate the relationship of fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVH) with haemodynamic abnormality and severity of arterial stenosis in patients with transient ischemic attack (TIA) of the carotid artery system. Patients and Methods. Consecutive inpatients (N = 38) diagnosed with TIAs of the carotid system in a 4-year period (2014-2017) were retrospectively analysed in our study and divided into FVH-negative and FVH-positive groups based on the presence of FVH sign. Each inpatient had undergone magnetic resonance imaging (MRI) followed by computed tomography (CT) perfusion imaging studies. We investigated the degree of arterial stenosis, number of stenosis, watershed regions, and related CT perfusion indexes, including hypoperfusion regions, mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV). Spearman rank correlation was performed between FVHs score, the degree of arterial stenosis, and CT perfusion indexes with significant difference. RESULTS: Thirty-one patients (81.6%) observed with FVH sign were assigned to the FVH-positive group. The hypoperfusion regions, MTT, and CBF values were significantly different between the FVH-negative group and FVH-positive groups. Spearman correlation analysis showed significant positive correlations between hypoperfusion regions, MTT, and FVHs scores (r = 0.755 and 0.674, respectively, p < 0.01); a moderate negative correlation was found between CBF and FVHs scores (r = 0.755 and 0.674, respectively, p < 0.01); a moderate negative correlation was found between CBF and FVHs scores (r = 0.755 and 0.674, respectively, p < 0.01); a moderate negative correlation was found between CBF and FVHs scores (. CONCLUSION: Hyperintense vessels on FLAIR were closely associated with hypoperfused regions, MTT, and CBF values, which indicated that the presence of FVHs could be an important and convenient imaging marker of haemodynamic impairment in patients with TIA.

Characterization of apolipoprotein A-I peptide phospholipid interaction and its effect on HDL nanodisc assembly.

Background: Synthetic HDLs (sHDLs), small nanodiscs of apolipoprotein mimetic peptides surrounding lipid bilayers, were developed clinically for atheroma regression in cardiovascular patients. Formation of HDL involves interaction of apolipoprotein A-I (ApoA-I) with phospholipid bilayers and assembly into lipid-protein nanodiscs. Purpose: The objective of this study is to improve understanding of physico-chemical aspects of HDL biogenesis such as the thermodynamics of ApoA-I-peptide membrane insertion, lipid binding, and HDL self-assembly to improve our ability to form homogeneous sHDL nanodiscs that are suitable for clinical administration. Methods: The ApoA-I-mimetic peptide, 22A, was combined with either egg sphingomyelin (eSM) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) phospholipid vesicles to form sHDL. The sHDL assembly process was investigated through lipid vehicle solubilization assays and characterization of purity, size, and morphology of resulting nanoparticles via gel permeation chromatography (GPC), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Peptide-lipid interactions involved were further probed by sum frequency generation (SFG) vibrational spectroscopy and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The pharmacokinetics of eSM-sHDL and POPC-sHDL nanodiscs were investigated in Sprague Dawley rats. Results: sHDL formation was temperature-dependent, with spontaneous formation of sHDL nanoparticles occurring only at temperatures exceeding lipid transition temperatures as evidenced by DLS, GPC, and TEM characterization. SFG and ATR-FTIR spectroscopy findings support a change in peptide-lipid bilayer interactions at temperatures above the lipid transition temperature. Lipid-22A interactions were stronger with eSM than with POPC, which resulted in the formation of more homogeneous sHDL nanoparticles with longer in vivo circulation time as evidenced the PK study. Conclusion: Physico-chemical characteristics of sHDL are in part determined by phospholipid composition. Optimization of phospholipid composition may be utilized to improve the stability and homogeneity of sHDL.

White Matter Hyperintensities Predict Cognitive Decline: A Community-Based Study.

INTRODUCTION: White matter hyperintensities (WMHs) were commonly seen in brain magnetic resonance imaging (MRI) of the elderly. Many studies found that WMHs were associated with cognitive decline and dementia. However, the association between WMHs in different brain regions and cognitive decline remains debated. METHODS: We explored the association of the severity of WMHs and cognitive decline in 115 non-demented elderly (≥50 years old) sampled from the Wuliqiao Community located in urban area of Shanghai. MRI scans were done during 2009-2011 at the beginning of the study. Severity of WMHs in different brain regions was scored by Improved Scheltens Scale and Cholinergic Pathways Hyperintensities Scale (CHIPS). Cognitive function was evaluated by Mini-Mental State Examination (MMSE) every 2 to 4 years during 2009-2018. RESULTS: After adjusting for confounding factors including age, gender, education level, smoking status, alcohol consumption, depression, hypertension, diabetes, hyperlipidemia, brain infarcts, brain atrophy, apoE4 status, and baseline MMSE score, periventricular and subcortical WMH lesions as well as WMHs in cholinergic pathways were significantly associated with annual MMSE decline ( p < 0.05), in which the severity of periventricular WMHs predicted a faster MMSE decline (-0.187 points/year, 95% confidence interval: -0.349, -0.026, p = 0.024). CONCLUSIONS: The severity of WMHs at baseline was associated with cognitive decline in the non-demented elderly over time. Interventions on WMH lesions may offer some benefits for cognitive deterioration.

Des hyper-signaux de la substance blanche prédicteurs du déclin cognitif : une étude menée dans une communauté locale.Introduction: Des hyper-signaux de la substance blanche (HSSB) peuvent généralement être observés lors d'examens d'imagerie par résonnance magnétique (IRM) effectués chez des personnes âgées. Plusieurs études ont également montré que les HSSB étaient associés au déclin cognitif et à la démence. Cela dit, le lien pouvant exister entre ces HSSB détectés dans diverses régions cérébrales et le déclin cognitif demeure sujet à débat. Méthodes: Nous avons décidé d'explorer l'association existant entre l'intensité des HSSB et le déclin cognitif chez 115 personnes âgées n'étant pas atteintes de démence (≥50 ans). Ces personnes avaient été recrutées au sein du quartier de Wuliqiao situé dans le grand Shanghai. Signalons que ces examens d'IRM ont été effectués au début de cette étude entre 2009 et 2011. L'intensité des HSSB dans diverses régions cérébrales a été mesurée au moyen des échelles suivantes : la Improved Scheltens Scale et la Cholinergic Pathways Hyperintensities Scale (CHIPS). En ce qui concerne la fonction cognitive, elle a été évaluée à l'aide du test de Folstein (ou mini-mental state examination) tous les 2 à 4 ans entre 2009 et 2018. Résultats: Une fois la prise en compte d'un certain nombre de facteurs de confusion (l'âge, le sexe, le niveau de scolarité, le tabagisme, la consommation d'alcool, la dépression, l'hypertension, le diabète, l'hyperlipidémie, des accidents ischémiques cérébraux, une atrophie du cerveau, la situation de l'allèle 4 du gène ApoE et le score initial au test de Folstein), il est apparu que des lésions révélées par des hyper-signaux des régions péri-ventriculaire et sous-corticale, de même que des hyper-signaux détectés dans les voies cholinergiques, étaient nettement associés à des résultats en baisse au test de Folstein en cours d'année (p < 0,05). Fait à noter, l'intensité des HSSB de la région péri-ventriculaire a aussi permis de prédire un déclin plus rapide des scores au test de Folstein (- 0,187 points/année, IC 95 % : - 0,349 - 0,026; p = 0,024). Conclusions: L'intensité des HSSB observée au début de cette étude a été associée au fil du temps au déclin cognitif de personnes âgées n'étant pas atteintes de démence. Il est donc possible que des interventions ciblant des lésions révélées par des HSSB puissent offrir certains bienfaits quand il est question de déclin cognitif.

Locally advanced gastric cancer: total iodine uptake to predict the response of primary lesion to neoadjuvant chemotherapy.

PURPOSE: Pathologic response to neoadjuvant chemotherapy is a prognostic factor in many cancer types. However, the existing evaluative criteria are deficient. We sought to prospectively evaluate the total iodine uptake derived from dual-energy computed tomography (DECT) in predicting treatment efficacy and progression-free survival (PFS) time in gastric cancer after neoadjuvant chemotherapy. METHODS: From October 2012 to December 2015, 44 patients with locally advanced gastric cancer were examined with DECT 1 week before and three cycles after neoadjuvant chemotherapy. The percentage changes in tumor area (%ΔS), diameter (%ΔD), and density (%ΔHU) were calculated to evaluate the WHO, RESCIST, and Choi criteria. The percentage changes in tumor volume (%ΔV) and total iodine uptake of portal phase (%ΔTIU-p) were also calculated to determine cut-off values by ROC curves. The correlation between the different criteria and histopathologic tumor regression grade (Becker score) or PFS were statistically analyzed. RESULTS: Forty-four patients were divided into responders and non-responders according to 43.34% volume reduction (P = 0.002) and 63.87% (P = 0.002) TIU-p reduction, respectively. The %ΔTIU-p showed strong (r = 0.602, P = 0.000) and %ΔV showed moderate (r = 0.416, P = 0.005), while the WHO (r = 0.075, P = 0.627), RECIST (r = 0.270, P = 0.077) and Choi criteria (r = 0.238, P = 0.120) showed no correlation with the Becker score. The differences in PFS time between the responder and non-responder groups were significant according to %ΔTIU-p and Choi criteria (P = 0.001 and P = 0.013, respectively). CONCLUSIONS: The TIU-p can help predict pathological regression in advanced gastric cancer patients after neoadjuvant chemotherapy. In addition, the %ΔTIU-p could be one of the potentially valuable predictive parameters of the PFS time.

Near-infrared light-responsive nanoparticles with thermosensitive yolk-shell structure for multimodal imaging and chemo-photothermal therapy of tumor.

Thermosensitive yolk-shell nanoparticles were developed as remote-controlled targeting drug delivery platform for multimodal imaging and combined therapy of cancer. The nanoparticles were fabricated using magnetic Fe3O4 nanoparticles as photothermal cores, thermo-responsive poly(N-isopropylacrylamide)-co-1-Vinyl-2-pyrrolidone p(NIPAM-co-NVP) as shells (Fe3O4-PNIPAM), with a hollow space between the two layers for loading of chemotherapeutic drug. The magnetic iron oxide nanoparticle cores could absorb and transform light to heat efficiently upon the irradiation of near infrared (NIR) laser, resulting in the shrink of the PNIPAM shell and the release of chemo-drugs. In vivo fluorescence/photoacoustic images demonstrated that Fe3O4-PNIPAM nanoparticles could accumulate in the tumor after intravenous injection. Upon the irradiation of the NIR laser, DOX-Fe3O4-PNIPAM nanoparticles exhibited outstanding synergistic effect. The tumor inhibition rate increased from 40.3% (DOX-Fe3O4-PNIPAM alone) and 65.2% (Fe3O4-PNIPAM +NIR) to 91.5%. The results demonstrated that the NIR-responsive nanocarrier offers a novel strategy for cancer theranostics and combined therapy of cancer.

Secreted frizzled-related protein 1 overexpression in gastric cancer: Relationship with radiological findings of dual-energy spectral CT and PET-CT.

We explored the role of secreted frizzled-related protein 1 (sFRP1) overexpression in gastric cancer and its relationship with radiological findings from dual-energy spectral CT(DEsCT) and positron emission tomography/computed tomography (PET/CT). We established mouse metastatic models using the SGC-7901/sFRP1 gastric cancer cell line. A control group was established using the SGC-7901/vector cell line. The models were then scanned with dual-energy spectral CT and PET-CT. Subsequent analysis, including immunohistochemistry and Transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL), was performed to confirm the role of sFRP1. Transwell chamber and angiogenesis assays were conducted to verify the effect of sFRP1 in vitro. We found that the control group showed negative radiological performance with successful implantation. Concurrently, the treated group showed visible lesions, a higher FDG uptake and increasing enhancement. The immunological and histological analysis confirmed the positive radiological performance with larger size, increasing proliferation, more microvessels and less apoptosis. The angiogenic up-regulation of sFRP1 overexpression were further verified with in vitro cell models. This preliminary study demonstrates that sFRP1 overexpression in gastric cancer cells leads to increased cell proliferation and angiogenesis, which may, in turn, contribute to positive PET/CT and CT performances.

Do guanidinium and tetrapropylammonium ions specifically interact with aromatic amino acid side chains?

Many ions are known to affect the activity, stability, and structural integrity of proteins. Although this effect can be generally attributed to ion-induced changes in forces that govern protein folding, delineating the underlying mechanism of action still remains challenging because it requires assessment of all relevant interactions, such as ion-protein, ion-water, and ion-ion interactions. Herein, we use two unnatural aromatic amino acids and several spectroscopic techniques to examine whether guanidinium chloride, one of the most commonly used protein denaturants, and tetrapropylammonium chloride can specifically interact with aromatic side chains. Our results show that tetrapropylammonium, but not guanidinium, can preferentially accumulate around aromatic residues and that tetrapropylammonium undergoes a transition at ∼1.3 M to form aggregates. We find that similar to ionic micelles, on one hand, such aggregates can disrupt native hydrophobic interactions, and on the other hand, they can promote α-helix formation in certain peptides.

Dentate nucleus iron deposition is a potential biomarker for tremor-dominant Parkinson's disease.

Parkinson's disease (PD) is a heterogeneous neurodegenerative disorder with variable clinicopathologic phenotypes and underlying neuropathologic mechanisms. Each clinical phenotype has a unique set of motor symptoms. Tremor is the most frequent initial motor symptom of PD and is the most difficult symptom to treat. The dentate nucleus (DN) is a deep iron-rich nucleus in the cerebellum and may be involved in PD tremor. In this study, we test the hypothesis that DN iron may be elevated in tremor-dominant PD patients using quantitative susceptibility mapping. Forty-three patients with PD [19 tremor dominant (TD)/24 akinetic rigidity (AR) dominant] and 48 healthy gender- and age-matched controls were recruited. Multi-echo gradient echo data were collected for each subject on a 3.0-T MR system. Inter-group susceptibility differences in the bilateral DN were investigated and correlations of clinical features with susceptibility were also examined. In contrast with the AR-dominant group, the TD group was found to have increased susceptibility in the bilateral DN when compared with healthy controls. In addition, susceptibility was positively correlated with tremor score in drug-naive PD patients. These findings indicate that iron load within the DN may make an important contribution to motor phenotypes in PD. Moreover, our results suggest that TD and AR-dominant phenotypes of PD can be differentiated on the basis of the susceptibility of the DN, at least at the group level. Copyright © 2016 John Wiley & Sons, Ltd.

Engineering and Characterization of Peptides and Proteins at Surfaces and Interfaces: A Case Study in Surface-Sensitive Vibrational Spectroscopy.

Understanding molecular structures of interfacial peptides and proteins impacts many research fields by guiding the advancement of biocompatible materials, new and improved marine antifouling coatings, ultrasensitive and highly specific biosensors and biochips, therapies for diseases related to protein amyloid formation, and knowledge on mechanisms for various membrane proteins and their interactions with ligands. Developing methods for measuring such unique systems, as well as elucidating the structure and function relationship of such biomolecules, has been the goal of our lab at the University of Michigan. We have made substantial progress to develop sum frequency generation (SFG) vibrational spectroscopy into a powerful technique to study interfacial peptides and proteins, which lays a foundation to obtain unique and valuable insights when using SFG to probe various biologically relevant systems at the solid/liquid interface in situ in real time. One highlighting feature of this Account is the demonstration of the power of combining SFG with other techniques and methods such as ATR-FTIR, surface engineering, MD simulation, liquid crystal sensing, and isotope labeling in order to study peptides and proteins at interfaces. It is necessary to emphasize that SFG plays a major role in these studies, while other techniques and methods are supplemental. The central role of SFG is to provide critical information on interfacial peptide and protein structure (e.g., conformation and orientation) in order to elucidate how surface engineering (e.g., to vary the structure) can ultimately affect surface function (e.g., to optimize the activity). This Account focuses on the most significant recent progress in research on interfacial peptides and proteins carried out by our group including (1) the development of SFG analysis methods to determine orientations of regular as well as disrupted secondary structures, and the successful demonstration and application of an isotope labeling method with SFG to probe the detailed local structure and microenvironment of peptides at buried interfaces, (2) systematic research on cell membrane associated peptides and proteins including antimicrobial peptides, cell penetrating peptides, G proteins, and other membrane proteins, discussing the factors that influence interfacial peptide and protein structures such as lipid charge, membrane fluidity, and biomolecule solution concentration, and (3) in-depth discussion on solid surface immobilized antimicrobial peptides and enzymes. The effects of immobilization method, substrate surface, immobilization site on the peptide or protein, and surrounding environment are presented. Several examples leading to high impact new research are also briefly introduced: The orientation change of alamethicin detected while varying the model cell membrane potential demonstrates the feasibility to apply SFG to study ion channel protein gating mechanisms. The elucidation of peptide secondary structures at liquid crystal interfaces shows promising results that liquid crystal can detect and recognize different peptides and proteins. The method of retaining the native structure of surface immobilized peptides or proteins in air demonstrates the feasibility to protect and preserve such structures via the use of hydromimetic functionalities when there is no bulk water. We hope that readers in many different disciplines will benefit from the research progress reported in this Account on SFG studies of interfacial structure-function relationships of peptides and proteins and apply this powerful technique to study interfacial biomolecules in the future.

Aortic Artery and Cardiac Valve Calcification are Associated with Mortality in Chinese Hemodialysis Patients: A 3.5 Years Follow-up.

BACKGROUND: This study was to investigate the relationship among aortic artery calcification (AAC), cardiac valve calcification (CVC), and mortality in maintenance hemodialysis (MHD) patients. METHODS: All MHD patients in Shanghai Ruijin Hospital in July 2011 were included. To follow up for 42 months, clinical data, predialysis blood tests, echocardiography, and lateral lumbar X-ray plain radiography results were collected. Plasma FGF23 level was measured using a C-terminal assay. RESULTS: Totally, 110 MHD patients were involved in this study. Of which, 64 (58.2%) patients were male, the mean age was 55.2 ± 1.4 years old, and the median dialysis duration was 29.85 (3.0-225.5) months. About 25.5% of the 110 MHD patients had CVC from echocardiography while 61.8% of the patients had visible calcification of aorta from lateral lumbar X-ray plain radiography. After 42 months follow-up, 25 (22.7%) patients died. Kaplan-Meier analysis showed that patients with AAC or CVC had a significant greater number of all-cause and cardiovascular deaths than those without. In multivariate analyses, the presence of AAC was a significant factor associated with all-cause mortality (hazard ratio [HR]: 3.149, P = 0.025) in addition to lower albumin level and lower 25-hydroxy Vitamin D (25(OH)D) level. The presence of CVC was a significant factor associated with cardiovascular mortality (HR: 3.800, P = 0.029) in addition to lower albumin level and lower 25(OH)D level. CONCLUSION: Lateral lumbar X-ray plain radiography and echocardiography are simple methods to detect AAC and CVC in dialysis patients. The presence of AAC and CVC was independently associated with mortality in MHD patients. Regular follow-up by X-ray and echocardiography could be a useful method to stratify mortality risk in MHD patients.

Region-specific disturbed iron distribution in early idiopathic Parkinson's disease measured by quantitative susceptibility mapping.

In Parkinson's disease (PD), iron elevation in specific brain regions as well as selective loss of dopaminergic neurons is a major pathologic feature. A reliable quantitative measure of iron deposition is a potential biomarker for PD and may contribute to the investigation of iron-mediated PD. The primary purpose of this study is to assess iron variations in multiple deep grey matter nuclei in early PD with a novel MRI technique, quantitative susceptibility mapping (QSM). The inter-group differences of susceptibility and R2* value in deep grey matter nuclei, namely head of caudate nucleus (CN), putamen (PUT), global pallidus (GP), substantia nigra (SN), and red nucleus (RN), and the correlations between regional iron deposition and the clinical features were explored in forty-four early PD patients and 35 gender and age-matched healthy controls. Susceptibility values were found to be elevated within bilateral SN and RN contralateral to the most affected limb in early PD compared with healthy controls (HCs). The finding of increased susceptibility in bilateral SN is consistent with work on a subgroup of patients at the earliest clinical detectable state (Hoehn and Yahr [1967]: Neurology 17:427-442; Stage I). However, increased R2* values were only seen within SN contralateral to the most affected limb in the PD group when compared with controls. Furthermore, bilateral SN magnetic susceptibility positively correlated with disease duration and UPDRS-III scores in early PD. This finding supports the potential value of QSM as a non-invasive quantitative biomarker of early PD.

Grating-based phase-contrast imaging of tumor angiogenesis in lung metastases.

PURPOSE: To assess the feasibility of the grating-based phase-contrast imaging (GPI) technique for studying tumor angiogenesis in nude BALB/c mice, without contrast agents. METHODS: We established lung metastatic models of human gastric cancer by injecting the moderately differentiated SGC-7901 gastric cancer cell line into the tail vein of nude mice. Samples were embedded in a 10% formalin suspension and dried before imaging. Grating-based X-ray phase-contrast images were obtained at the BL13W beamline of the Shanghai Synchrotron Radiation Facility (SSRF) and compared with histological sections. RESULTS: Without contrast agents, grating-based X-ray phase-contrast imaging still differentiated angiogenesis within metastatic tumors with high spatial resolution. Vessels, down to tens of microns, showed gray values that were distinctive from those of the surrounding tumors, which made them easily identifiable. The vessels depicted in the imaging study were similar to those identified on histopathology, both in size and shape. CONCLUSIONS: Our preliminary study demonstrates that grating-based X-ray phase-contrast imaging has the potential to depict angiogenesis in lung metastases.

Site-specific orientation of an α-helical peptide ovispirin-1 from isotope-labeled SFG spectroscopy.

Sum-frequency generation (SFG) vibrational spectroscopy is often used to probe the backbone structures and orientations of polypeptides at surfaces. Using the ovispirin-1 polypeptide at the solid/liquid interface of polystyrene, we demonstrate for the first time that SFG can probe the polarization response of a single-isotope-labeled residue. To interpret the spectral intensities, we simulated the spectra using an excitonic Hamiltonian approach. We show that the polarization dependence of either the label or the unlabeled amide I band alone does not provide sufficient structural constraints to obtain both the tilt and the twist of the ovispirin helix at a solid/liquid interface, but that both can be determined from the polarization dependence of the complete spectrum. For ovispirin, the detailed analysis of the polarized SFG experimental data shows that the helix axis is tilted at roughly 138° from the surface normal, and the transition dipole of the isotope-labeled C═O group is tilted at 23° from the surface normal, with the hydrophobic region facing the polystyrene surface. We further demonstrate that the Hamiltonian approach is able to address the coupling effect and the structural disorder. For comparison, we also collected the FTIR spectrum of ovispirin under similar conditions, which reveals the enhanced sensitivity of SFG for structural studies of single monolayer peptide surfaces. Our study provides insight into how structural and environmental effects appear in SFG spectra of the amide I band and establishes that SFG of isotope-labeled peptides will be a powerful technique for elucidating secondary structures with residue-by-residue resolution.

Gastric cancer staging with dual energy spectral CT imaging.

PURPOSE: To evaluate the clinical utility of dual energy spectral CT (DEsCT) in staging and characterizing gastric cancers. MATERIALS AND METHODS: 96 patients suspected of gastric cancers underwent dual-phasic scans (arterial phase (AP) and portal venous phase (PP)) with DEsCT mode. Three types of images were reconstructed for analysis: conventional polychromatic images, material-decomposition images, and monochromatic image sets with photon energies from 40 to 140 keV. The polychromatic and monochromatic images were compared in TNM staging. The iodine concentrations in the lesions and lymph nodes were measured on the iodine-based material-decomposition images. These values were further normalized against that in aorta and the normalized iodine concentration (nIC) values were statistically compared. Results were correlated with pathological findings. RESULTS: The overall accuracies for T, N and M staging were (81.2%, 80.0%, and 98.9%) and (73.9%, 75.0%, and 98.9%) determined with the monochromatic images and the conventional kVp images, respectively. The improvement of the accuracy in N-staging using the keV images was statistically significant (p<0.05). The nIC values between the differentiated and undifferentiated carcinoma and between metastatic and non-metastatic lymph nodes were significantly different both in AP (p = 0.02, respectively) and PP (p = 0.01, respectively). Among metastatic lymph nodes, nIC of the signet-ring cell carcinoma were significantly different from the adenocarcinoma (p = 0.02) and mucinous adenocarcinoma (p = 0.01) in PP. CONCLUSION: The monochromatic images obtained with DEsCT may be used to improve the N-staging accuracy. Quantitative iodine concentration measurements may be helpful for differentiating between differentiated and undifferentiated gastric carcinoma, and between metastatic and non-metastatic lymph nodes.