Bimetallic AuCu nanoclusters-based florescent chemosensor for sensitive detection of Fe3+ in environmental and biological systems

Assays of ferric ion (Fe³⁺) with high sensitivity and selectivity have been required to evaluate its amount in environmental and biological systems. Herein, a novel fluorometric penicillamine-capped bimetallic gold-copper nanoclusters (PA-AuCu bi-MNCs) sensor was constructed for facile, environmentally friendly and quantitative detection of Fe³⁺ through inner filter effect (IFE) mechanism. One-step green synthetic approach was applied for the synthesis of AuCu bi-MNCs by using d-penicillamine (D-PA) as template and stabilizer. In the presence of Fe³⁺, the emission of the PA-AuCu bi-MNCs was hindered that caused selective quenching of the fluorescence intensity. The response to Fe³⁺ allows for two linear dynamic ranges of 5.0 × 10^-7 M-7.0 × 10^-6 M and 7.0 × 10^-6 M-1.0 × 10^-4 M with a detection limit of 0.1 μM, which is approximately 53 times lower than the maximum level (5.37 μM) of Fe³⁺ in drinking water that had been reported by the World Health Organization. The independency of the system from most of the interferences is the important feature of this work. Beside the appropriate selectivity of the proposed method, it shows a considerable operation in various environmental samples including rain water, three types of river water and also in human blood serum as a biological matrix.

Bioactive glass ions induce efficient osteogenic differentiation of human adipose stem cells encapsulated in gellan gum and collagen type I hydrogels

BACKGROUND

Due to unmet need for bone augmentation, our aim was to promote osteogenic differentiation of human adipose stem cells (hASCs) encapsulated in gellan gum (GG) or collagen type I (COL) hydrogels with bioactive glass (experimental glass 2-06 of composition [wt-%]: Na₂O 12.1, K₂O 14.0, CaO 19.8, P₂O5 2.5, B₂O₃ 1.6, SiO₂ 50.0) extract based osteogenic medium (BaG OM) for bone construct development. GG hydrogels were crosslinked with spermidine (GG-SPD) or BaG extract (GG-BaG).

METHODS

Mechanical properties of cell-free GG-SPD, GG-BaG, and COL hydrogels were tested in osteogenic medium (OM) or BaG OM at 0, 14, and 21 d. Hydrogel embedded hASCs were cultured in OM or BaG OM for 3, 14, and 21 d, and analyzed for viability, cell number, osteogenic gene expression, osteocalcin production, and mineralization. Hydroxyapatite-stained GG-SPD samples were imaged with Optical Projection Tomography (OPT) and Selective Plane Illumination Microscopy (SPIM) in OM and BaG OM at 21 d. Furthermore, Raman spectroscopy was used to study the calcium phosphate (CaP) content of hASC-secreted ECM in GG-SPD, GG-BaG, and COL at 21 d in BaG OM.

RESULTS

The results showed viable rounded cells in GG whereas hASCs were elongated in COL. Importantly, BaG OM induced significantly higher cell number and higher osteogenic gene expression in COL. In both hydrogels, BaG OM induced strong mineralization confirmed as CaP by Raman spectroscopy and significantly improved mechanical properties. GG-BaG hydrogels rescued hASC mineralization in OM. OPT and SPIM showed homogeneous 3D cell distribution with strong mineralization in BaG OM. Also, strong osteocalcin production was visible in COL.

CONCLUSIONS

Overall, we showed efficacious osteogenesis of hASCs in 3D hydrogels with BaG OM with potential for bone-like grafts.

Detection and Inhibition of Bacteria on a Dual-Functional Silver Platform

Detection and inhibition of bacteria are universally required in clinics and daily life for health care. Developing a dual-functional material is challenging and in demand, engaging advanced applications for both defined bioanalysis and targeted biotoxicity. Herein, magnetic silver nanoshells are designed as a multifunctional platform for the detection and inhibition of bacteria. The optimized magnetic silver nanoshells enable direct laser desorption/ionization mass spectrometry based metabolic analysis of bacteria (≈10 µL^-1 ), in complex biofluids. The serum infection process (0-10 h) is monitored by statistics toward clinical classification. Moreover, magnetic silver nanoshells facilitate surface adhesion on bacteria due to nanoscale surface roughness and thus display long-term antibacterial effects. Bacteria metabolism is studied with metabolic biomarkers (e.g., malate and lysine) identified during inhibition, showing cell membrane destruction and dysfunctional protein synthesis mechanisms. This work not only guides the design of material-based approaches for bioanalysis and biotoxicity, but contributes to bacteria-related diagnosis by using specific metabolic biomarkers for sensitive detection and new insights by monitoring metabolomic change of bacteria for antibacterial applications.

Enzyme-Linked Immunosorbent Assay for T-Cell Dependent Immunogenicity Assessment of Therapeutic Peptides

Immunogenicity assessment of therapeutic peptides, proteins, oligonucleotides, and hybrid molecules, such as nucleopeptides, is a major aspect in understanding their safety and efficacy. Both T-cell independent and dependent immune reactions contribute to an immunogenic response against antigen, including secretion of cytokines and production of an antigen-specific antibody. Various assays exist for detecting and quantifying such immunogenic responses by human T-cells ex vivo or in mouse serum, which primarily include enzyme-linked immunosorbent assay (ELISA, direct and indirect), flow-cytometry and surface plasmon resonance (SPR). ELISA is a popular choice due to its robustness, reliability, sensitivity, ease of automation, and the requirement of simple equipment commonly available in most molecular biology and biochemistry laboratories. The chapter describes the detailed protocol of cytokine analysis by an ELISA method and highlights few crucial steps to be considered while performing the assay for successful immunogenicity studies.

Determination of Autoantibodies to Transglutaminase by Electrochemiluminescence (ECL) Assay

Appearance of autoantibodies to tissue transglutaminase (TGA) is the most reliable biomarker to identify celiac disease autoimmunity. A nonradioactive assay of determination of TGA was newly developed using electrochemiluminescence (ECL) technology. This ECL assay has been demonstrated to be more sensitive than current standard radio-binding assay (RBA) in detecting TGA and can detect TGA earlier among high-risk young children followed from birth.

Detection and Inhibition of Bacteria on a Dual-Functional Silver Platform

Detection and inhibition of bacteria are universally required in clinics and daily life for health care. Developing a dual-functional material is challenging and in demand, engaging advanced applications for both defined bioanalysis and targeted biotoxicity. Herein, magnetic silver nanoshells are designed as a multifunctional platform for the detection and inhibition of bacteria. The optimized magnetic silver nanoshells enable direct laser desorption/ionization mass spectrometry based metabolic analysis of bacteria (≈10 µL^-1 ), in complex biofluids. The serum infection process (0-10 h) is monitored by statistics toward clinical classification. Moreover, magnetic silver nanoshells facilitate surface adhesion on bacteria due to nanoscale surface roughness and thus display long-term antibacterial effects. Bacteria metabolism is studied with metabolic biomarkers (e.g., malate and lysine) identified during inhibition, showing cell membrane destruction and dysfunctional protein synthesis mechanisms. This work not only guides the design of material-based approaches for bioanalysis and biotoxicity, but contributes to bacteria-related diagnosis by using specific metabolic biomarkers for sensitive detection and new insights by monitoring metabolomic change of bacteria for antibacterial applications.

Guidelines for CSF Processing and Biobanking: Impact on the Identification and Development of Optimal CSF Protein Biomarkers

The field of neurological diseases strongly needs biomarkers for early diagnosis and optimal stratification of patients in clinical trials or to monitor disease progression. Cerebrospinal fluid (CSF) is one of the main sources for the identification of novel protein biomarkers for neurological diseases. Despite the enormous efforts employed to identify novel CSF biomarkers, the high variability observed across different studies has hampered their validation and implementation in clinical practice. Such variability is partly caused by the effect of different pre-analytical confounding factors on protein stability, highlighting the importance to develop and comply with standardized operating procedures. In this chapter, we describe the international consensus pre-analytical guidelines for CSF processing and biobanking that have been established during the last decade, with a special focus on the influence of pre-analytical confounders on the global CSF proteome. In addition, we provide novel results on the influence of different delayed storage and freeze/thaw conditions on the CSF proteome using two novel large multiplex protein arrays (SOMAscan and Olink). Compliance to consensus guidelines will likely facilitate the successful development and implementation of CSF protein biomarkers in both research and clinical settings, ultimately facilitating the successful development of disease-modifying therapies.

Biological tests carried out on serum/plasma samples from donors of human body material for transplantation: Belgian experience and practical recommendations

This paper on the biological tests carried out on serum/plasma samples from donors of human body material (HBM) is the result of a project of the working Group of Superior Health Council of Belgium formed with experts in the field of HBM and infectious serology. Indeed, uncertainty about the interpretation of biological test results currently leads to the sometimes unjustified cancelling of planned donations or the rejection of harvested HBM, whilst more sophisticated diagnostic algorithms would still allow the use of organs or HBM that would otherwise have been rejected. NAT tests will not be discussed in this publication. In the first part some general aspects as the need for a formal agreement between the Tissue Establishment l and the laboratory responsible for the biological testing, but also some specifications regarding testing material, the choice of additional biological tests, and some general aspects concerning interpretation and reporting are discussed. In a second part, detailed information and recommendations concerning the interpretation are presented for each of the mandatory tests (human immunodeficiency virus, hepatitis B virus, hepatitis C virus and syphilis) is presented. A number of not mandatory, but regularly used optional serological tests (e.g. for the detection of antibodies to Toxoplasma gondii, Epstein-Barr virus, human T cell leukemia virus and cytomegalovirus) are also extensively discussed. Although the project was meant to provide clarification and recommendations concerning the Belgian legislation, the majority of recommendations are also applicable to testing of donors of tissues and cells in other (European) countries.

Mapping the O-glycoproteome using site-specific extraction of O-linked glycopeptides (EXoO)

Protein glycosylation is one of the most abundant post-translational modifications. However, detailed analysis of O-linked glycosylation, a major type of protein glycosylation, has been severely impeded by the scarcity of suitable methodologies. Here, a chemoenzymatic method is introduced for the site-specific extraction of O-linked glycopeptides (EXoO), which enabled the mapping of over 3,000 O-linked glycosylation sites and definition of their glycans on over 1,000 proteins in human kidney tissues, T cells, and serum. This large-scale localization of O-linked glycosylation sites demonstrated that EXoO is an effective method for defining the site-specific O-linked glycoproteome in different types of sample. Detailed structural analysis of the sites identified revealed conserved motifs and topological orientations facing extracellular space, the cell surface, the lumen of the Golgi, and the endoplasmic reticulum (ER). EXoO was also able to reveal significant differences in the O-linked glycoproteome of tumor and normal kidney tissues pointing to its broader use in clinical diagnostics and therapeutics.

Exploring pathogenesis in subjects with subjective Tinnitus having kidney deficiency pattern in terms of Traditional Chinese Medicine based on serum metabolic profiles

OBJECTIVE

To investigate the metabolic pathogenesis in subjects with subjective tinnitus (ST) having kidney deficiency pattern (KDP) (ST/KDP) in terms of Traditional Chinese Medicine.

METHODS

Three groups of subjects, including healthy individuals, subjects with ST/KDP, and subjects who were healthy initially and then developed ST/KDP one year later (healthy ¡ú ST/KDP), were recruited for this study. Serum metabolic profiles of all subjects were analyzed using ultra-performance liquid chromatography coupled with quadruple-time-of-flight mass spectrometry. The metabolic characteristics of the ST/KDP subjects were determined, and the corresponding biomarkers were predicted. The metabolomics data from the healthy ¡ú ST/KDP subjects were collected for further verification.

RESULTS

Twelve metabolites in the ST/KDP subjects were different from those of the healthy control subjects. Of these metabolites, according to the prediction, except for octanoic acid, other metabolites might characterize ST/KDP. Ten metabolites at the outcome ST/KDP stage were different from those at the initial (control) stage. Through the comparison of these metabolites with the predicted metabolites, five common metabolites, including upregulated glutamate, serotonin, orotic acid and 8-oxoguanine, as well as downregulated taurine, were found. These common metabolites were significantly associated with canonical pathways including calcium signaling, ¦Ã-aminobutyric acid (GABA) receptor signaling, purine and pyrimidine biosynthesis, taurine biosynthesis, and serotonin receptor signaling.

CONCLUSION

The metabolic pathogenesis in ST/KDP subjects was characterized by upregulated glutamate, serotonin, orotic acid and 8-oxoguanine, as well as downregulated taurine, additionally, perturbations of calcium signaling, GABA receptor signaling, purine and pyrimidine biosynthesis, taurine biosynthesis, and serotonin receptor signaling.

Melatonin protects hippocampal HT22 cells from the effects of serum deprivation specifically targeting mitochondria

Neurons contain a high number of mitochondria, these neuronal cells produce elevated levels of oxidative stress and live for a long time without proliferation; therefore, mitochondrial homeostasis is crucial to their health. Investigations have recently focused on mitochondrial dynamics revealing the ability of these organelles to change their distribution and morphology. It is known that mitochondrial fission is necessary for the transmission of mitochondria to daughter cells during mitosis and mitochondrial fragmentation has been used as an indicator of cell death and mitochondrial dysfunction. Oxidative stress is a trigger able to induce changes in the mitochondrial network. The aim of the present study was to determine the effects of melatonin on the mitochondrial network in HT22 serum-deprived cells. Our results showed that serum deprivation increased reactive oxygen species (ROS) content, promoted the activation of plasma membrane voltage-dependent anion channels (VDACs) and affected the expression of pDRP1 and DRP1 fission proteins. Moreover, parallel increases in apoptotic and autophagic features were found. Damaged and dysfunctional mitochondria are deleterious to the cell; hence, the degradation of such mitochondria through mitophagy is crucial to cell survival. Our results suggest that melatonin supplementation reduces cell death and restores mitochondrial function through the regulation of autophagy.

Metabolomic identification of diagnostic serum-based biomarkers for advanced stage melanoma

INTRODUCTION

Melanoma is a highly aggressive malignancy and is currently one of the fastest growing cancers worldwide. While early stage (I and II) disease is highly curable with excellent prognosis, mortality rates rise dramatically after distant spread. We sought to identify differences in the metabolome of melanoma patients to further elucidate the pathophysiology of melanoma and identify potential biomarkers to aid in earlier detection of recurrence.

METHODS

Using ¹H NMR and DI-LC-MS/MS, we profiled serum samples from 26 patients with stage III (nodal metastasis) or stage IV (distant metastasis) melanoma and compared their biochemical profiles with 46 age- and gender-matched controls.

RESULTS

We accurately quantified 181 metabolites in serum using a combination of ¹H NMR and DI-LC-MS/MS. We observed significant separation between cases and controls in the PLS-DA scores plot (permutation test p-value = 0.002). Using the concentrations of PC-aa-C40:3, DL-carnitine, octanoyl-L-carnitine, ethanol, and methylmalonyl-L-carnitine we developed a diagnostic algorithm with an AUC (95% CI) = 0.822 (0.665-0.979) with sensitivity and specificity of 100 and 56%, respectively. Furthermore, we identified arginine, proline, tryptophan, glutamine, glutamate, glutathione and ornithine metabolism to be significantly perturbed due to disease (p < 0.05).

CONCLUSION

Targeted metabolomic analysis demonstrated significant differences in metabolic profiles of advanced stage (III and IV) melanoma patients as compared to controls. These differences may represent a potential avenue for the development of multi-marker serum-based assays for earlier detection of recurrences, allow for newer, more effective targeted therapy when tumor burden is less, and further elucidate the pathophysiologic changes that occur in melanoma.

MALDI-TOF analysis of blood serum proteome can predict the presence of monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell dyscrasia that can progress to malignant multiple myeloma (MM). Specific molecular biomarkers to classify the MGUS status and discriminate the initial asymptomatic phase of MM have not been identified. We examined the serum peptidome profile of MGUS patients and healthy volunteers using MALDI-TOF mass spectrometry and developed a predictive model for classifying serum samples. The predictive model was built using a support vector machine (SVM) supervised learning method tuned by applying a 20-fold cross-validation scheme. Predicting class labels in a blinded test set containing randomly selected MGUS and healthy control serum samples validated the model. The generalization performance of the predictive model was evaluated by a double cross-validation method that showed 88% average model accuracy, 89% average sensitivity and 86% average specificity. Our model, which classifies unknown serum samples as belonging to either MGUS patients or healthy individuals, can be applied to clinical diagnosis.

Inhibitors of lysosomal function or serum starvation in control or LAMP2 deficient cells do not modify the cellular levels of Parkinson disease-associated DJ-1/PARK 7 protein

Mutations in PARK7/DJ-1 gene are associated with familial autosomal recessive Parkinson disease. Recently, lysosomes and chaperone mediated autophagy (CMA) has been reported to participate in the degradation of DJ-1/PARK7 protein. Lamp-2A isoform is considered as the lysosomal receptor for the uptake of proteins being degraded by the CMA pathway. We have used several cell lines with disrupted LAMP2 gene expression and their respective control cells to test the possible role of lysosomal degradation and in particular CMA in DJ-1 /PARK7 degradation. Interruption of LAMP-2 expression did not result in an increase of the steady-state protein levels of DJ-1 /PARK7, as it would have been expected. Furthermore, no change in DJ-1 /PARK7 protein levels were observed upon inhibition of lysosomal function with NH₄Cl or NH₄Cl plus leupeptin, or after activation of CMA by serum starvation for 24h. Accordingly, we have not found any evidence that DJ-1 /PARK7 protein levels are regulated via lysosomal degradation or the CMA pathway.

High-Performance Chemical Isotope Labeling Liquid Chromatography Mass Spectrometry for Exosome Metabolomics

Circulating exosomes in bodily fluids such as blood are being actively studied as a rich source of chemical biomarkers for cancer diagnosis and monitoring. Although nucleic acid analysis is a primary tool for the discovery of circulating biomarkers in exosomes, metabolomics holds the potential of expanding the chemical diversity of biomarkers that may be easy and rapid to detect. However, only trace amounts of exosomes can be isolated from a small volume of patient blood, and thus a very sensitive technique is required to analyze the metabolome of exosomes. In this report, we present a workflow that involves multiple cycles of ultracentrifugation for exosome isolation using a starting material of 2 mL of human serum, freeze-thaw-cycles in 50% methanol/water for exosome lysis and metabolite extraction, differential chemical isotope labeling (CIL) of metabolites for enhancing liquid chromatography (LC) separation and improving mass spectrometry (MS) detection, and nanoflow LC-MS (nLC-MS) with captivespray for analysis. As a proof-of-principle, we used dansylation labeling to analyze the amine- and phenol-submetabolomes in two sets of exosome samples isolated from the blood samples of five pancreatic cancer patients before and after chemotherapy treatment. The average number of peak pairs or metabolites detected was 1964 ± 60 per sample for a total of 2446 peak pairs ( n = 10) in the first set and 1948 ± 117 per sample for a total of 2511 peak pairs ( n = 10) in the second set. There were 101 and 94 metabolites positively identified in the first and second set, respectively, and 1580 and 1590 peak pairs with accurate masses matching those of metabolites in the MyCompoundID metabolome database. Analyzing the mixtures of 12C-labeled individual exosome samples spiked with a 13C-labeled pooled sample which served as an internal standard allowed relative quantification of metabolomic changes of exosomes of blood samples collected before and after treatment.

IL22 Inhibits Epithelial Stem Cell Expansion in an Ileal Organoid Model

Background & Aims

Crohn's disease is an inflammatory bowel disease that affects the ileum and is associated with increased cytokines. Although interleukin (IL)6, IL17, IL21, and IL22 are increased in Crohn's disease and are associated with disrupted epithelial regeneration, little is known about their effects on the intestinal stem cells (ISCs) that mediate tissue repair. We hypothesized that ILs may target ISCs and reduce ISC-driven epithelial renewal.

Methods

A screen of IL6, IL17, IL21, or IL22 was performed on ileal mouse organoids. Computational modeling was used to predict microenvironment cytokine concentrations. Organoid size, survival, proliferation, and differentiation were characterized by morphometrics, quantitative reverse-transcription polymerase chain reaction, and immunostaining on whole organoids or isolated ISCs. ISC function was assayed using serial passaging to single cells followed by organoid quantification. Single-cell RNA sequencing was used to assess Il22ra1 expression patterns in ISCs and transit-amplifying (TA) progenitors. An IL22-transgenic mouse was used to confirm the impact of increased IL22 on proliferative cells in vivo.

Results

High IL22 levels caused decreased ileal organoid survival, however, resistant organoids grew larger and showed increased proliferation over controls. Il22ra1 was expressed on only a subset of ISCs and TA progenitors. IL22-treated ISCs did not show appreciable differentiation defects, but ISC biomarker expression and self-renewal-associated pathway activity was reduced and accompanied by an inhibition of ISC expansion. In vivo, chronically increased IL22 levels, similar to predicted microenvironment levels, showed increases in proliferative cells in the TA zone with no increase in ISCs.

Conclusions

Increased IL22 limits ISC expansion in favor of increased TA progenitor cell expansion.

Determination of trace levels of eleven bisphenol A analogues in human blood serum by high performance liquid chromatography-tandem mass spectrometry

Chemicals showing structural or functional similarity to bisphenol A (BPA), commonly called BPA analogues, have recently drawn scientific attention due to their common industrial and commercial application as a substitute for BPA. In the European Union, the use of BPA has been severely restricted by law due to its endocrine disrupting properties. Unfortunately, it seems that all BPA analogues show comparable biological activity, including hormonal disruption, toxicity and genotoxicity. Until now, the knowledge about human exposure to BPA analogues is scarce, mainly due to the lack of the data concerning their occurrence in human derived biological samples. This study presents the development of an analytical method for determination of trace levels of eleven BPA analogues in human blood serum samples. The method involves fast and simple liquid-liquid extraction, using low sample and solvent volumes. Chromatographic separation of analytes was optimized using one-factor-at-a-time approach (mobile phase composition, gradient shape, chromatographic column selection, separation temperature, etc.). The method allows for effective separation of the analytes, even in the case of configurational isomers (bisphenol M and bisphenol P). The calibration curves for all analytes were linear in the range tested. The limits of detection and quantitation were in the range of 0.0079÷0.039ng/mL and 0.024÷0.12ng/mL respectively. Compound-dependent recovery values were in the rage of 88÷138%. Matrix effects were mitigated with the help of matrix-matched calibration curves prepared for every batch of samples. Results obtained after the analysis of 245 real human blood serum samples indicate that human beings are exposed to different BPA analogues, that are present in the environment and in common, daily use products.

Serum metabolite profile associated with incident type 2 diabetes in Koreans: findings from the Korean Genome and Epidemiology Study

The identification of metabolic alterations in type 2 diabetes (T2D) is useful for elucidating the pathophysiology of the disease and in classifying high-risk individuals. In this study, we prospectively examined the associations between serum metabolites and T2D risk in a Korean community-based cohort (the Ansan-Ansung cohort). Data were obtained from 1,939 participants with available metabolic profiles and without diabetes, cardiovascular disease, or cancer at baseline. The acylcarnitine, amino acid, amine, and phospholipid levels in fasting serum samples were analyzed by targeted metabolomics. During the 8-year follow-up period, we identified 282 cases of incident T2D. Of all metabolites measured, 22 were significantly associated with T2D risk. Specifically, serum levels of alanine, arginine, isoleucine, proline, tyrosine, valine, hexose and five phosphatidylcholine diacyls were positively associated with T2D risk, whereas lyso-phosphatidylcholine acyl C17:0 and C18:2 and other glycerophospholipids were negatively associated with T2D risk. The associated metabolites were further correlated with T2D-relevant risk factors such as insulin resistance and triglyceride indices. In addition, a healthier diet (as measured by the modified recommended food score) was independently associated with T2D risk. Alterations of metabolites such as amino acids and choline-containing phospholipids appear to be associated with T2D risk in Korean adults.

Metabolite Profiling of Feces and Serum in Hemodialysis Patients and the Effect of Medicinal Charcoal Tablets

BACKGROUND/AIMS

Recently, the colon has been recognized as an important source of various uremic toxins in patients with end stage renal disease. Medicinal charcoal tablets are an oral adsorbent that are widely used in patients with chronic kidney disease in China to remove creatinine and urea from the colon. A parallel fecal and serum metabolomics study was performed to determine comprehensive metabolic profiles of patients receiving hemodialysis (HD). The effects of medicinal charcoal tablets on the fecal and serum metabolomes of HD patients were also investigated.

METHODS

Ultra-performance liquid chromatography/mass spectrometry was used to investigate the fecal and serum metabolic profiles of 20 healthy controls and 31 HD patients before and after taking medicinal charcoal tablets for 3 months.

RESULTS

There were distinct metabolic variations between the HD patients and healthy controls both in the feces and serum according to multivariate data analysis. Metabolic disturbances of alanine, aspartate and glutamate metabolism, arginine and proline metabolism figured prominently in the serum. However, in the feces, alterations of tryptophan metabolism, lysine degradation and beta-alanine metabolism were pronounced, and the levels of several amino acids (leucine, phenylalanine, lysine, histidine, methionine, tyrosine, and tryptophan) were increased dramatically. Nineteen fecal metabolites and 21 serum metabolites were also identified as biomarkers that contributed to the metabolic differences. Additionally, medicinal charcoal treatment generally enabled the serum and fecal metabolomes of the HD patients to draw close to those of the control subjects, especially the serum metabolic profile.

CONCLUSION

Parallel fecal and serum metabolomics uncovered the systematic metabolic variations of HD patients, especially disturbances in amino acid metabolism in the colon. Medicinal charcoal tablets had an impact on the serum and fecal metabolomes of HD patients, but their exact effects still need to be studied further.

Proteolysis inhibition by hibernating bear serum leads to increased protein content in human muscle cells

Muscle atrophy is one of the main characteristics of human ageing and physical inactivity, with resulting adverse health outcomes. To date, there are still no efficient therapeutic strategies for its prevention and/or treatment. However, during hibernation, bears exhibit a unique ability for preserving muscle in conditions where muscle atrophy would be expected in humans. Therefore, our objective was to determine whether there are components of bear serum which can control protein balance in human muscles. In this study, we exposed cultured human differentiated muscle cells to bear serum collected during winter and summer periods, and measured the impact on cell protein content and turnover. In addition, we explored the signalling pathways that control rates of protein synthesis and degradation. We show that the protein turnover of human myotubes is reduced when incubated with winter bear serum, with a dramatic inhibition of proteolysis involving both proteasomal and lysosomal systems, and resulting in an increase in muscle cell protein content. By modulating intracellular signalling pathways and inducing a protein sparing phenotype in human muscle cells, winter bear serum therefore holds potential for developing new tools to fight human muscle atrophy and related metabolic disorders.

A lysosome-targetable turn-on fluorescent probe for the detection of thiols in living cells based on a 1,8-naphthalimide derivative

Biological thiols, like cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play crucial roles in biological systems and in lysosomal processes. Highly selective probes for detecting biological thiols in lysomes of living cells are rare. In this work, a lysosome-targetable turn-on fluorescent probe for the detection of thiols in living cells was designed and synthesized based on a 1,8-naphthalimide derivative. The probe has a 4-(2-aminoethyl)morpholine unit as a lysosome-targetable group and an acrylate group as the thiol recognition unit as well as a fluorescence quencher. In the absence of biothiols, the probe displayed weak fluorescence due to the photoinduced electron transfer (PET) process. Upon the addition of biothiols, the probe exhibited an enhanced fluorescence emission centered at 550nm due to cleavage of the acrylate moiety. The probe had high selectivity toward biothiols. Moreover, the probe features fast response time, excitation in the visible region and ability of working in a wide pH range. The linear response range covers a concentration range of Cys from 1.5×10^-7 to 1.0×10^-5mol·L^-1 and the detection limit is 6.9×10^-8mol·L^-1 for Cys. The probe has been successfully applied to the confocal imaging of biothiols in lysosomes of A549 cells with low cell toxicity. Furthermore, the method was successfully applied to the determination of thiols in a complex multicomponent mixture such as human serum, which suggests our proposed method has great potential for diagnostic purposes. All of such good properties prove it can be used to monitor biothiols in lysosomes of living cells and to be a good fluorescent probe for the selective detection of thiols.

Screening for Good Batches of Fetal Bovine Serum for Myeloma and Hybridoma Growth

Not all lots of fetal bovine serum (FBS) are good at supporting hybridoma growth at low density. The key constituents that distinguish good batches of serum from bad are not known. It is necessary to order test batches from several suppliers and screen them as described here or purchase prescreened serum directly from the distributor.

Pulsed electromagnetic fields (PEMF) attenuate changes in vertebral bone mass, architecture and strength in ovariectomized mice

Pulsed electromagnetic fields (PEMF) has been investigated as a noninvasive alternative method to prevent bone loss for postmenopausal osteoporosis (OP), and the bone tissue involved in these studies are usually long bones such as femur and tibia in OP patients or rat models. However, few studies have investigated the effects of PEMF on the vertebral bone in mice with OP. This study aimed to investigate whether PEMF preserve lumbar vertebral bone mass, microarchitecture and strength in ovariectomized (OVX) mouse model of OP and its associated mechanisms. Thirty 3-month-old female BALB/c mice were randomly divided into three groups (n=10): sham-operated control (Sham), ovariectomy (OVX), and ovariectomy with PEMF treatment (OVX+PEMF). The OVX+PEMF group was exposed to 15Hz, 1.6 mT PEMF for 8h/day, 7days/week. After 8weeks, the mice were sacrificed. The OVX+PEMF group showed lower body weight gain of mice induced by estrogen deficiency compared with OVX group. Biochemical analysis of serum demonstrated that serum bone formation markers including bone specific alkaline phosphatase (BALP), serum osteocalcin (OCN), osteoprotegerin (OPG) and N-terminal propeptide of type I procollagen (P1NP) were markedly higher in OVX+PEMF group compared with OVX group. Besides, serum bone resorption markers including tartrate-resistant acid phosphatase 5b (TRAP-5b) and C-terminal crosslinked telopeptides of type I collagen (CTX-I) were markedly lower in OVX+PEMF group compared with OVX group. Biomechanical test observed that OVX+PEMF group showed higher compressive maximum load and stiffness of the lumbar vertebrae compared with OVX group. Micro-computed tomography (μCT) and histological analysis of lumbar vertebrae revealed that PEMF partially prevented OVX-induced decrease of trabecular bone mass and deterioration of trabecular bone microarchitecture in lumbar vertebrae. Real-time PCR showed that the canonical Wnt signaling pathway of the lumbar vertebrae, including Wnt3a, LRP5 and β-catenin were markedly up-regulated in OVX+PEMF group compared with OVX group. Moreover, the mRNA expressions of RANKL and OPG were markedly up-regulated in OVX+PEMF group compared with OVX group, whereas no statistical difference in RANKL/OPG mRNA ratio was found between OVX+PEMF group and OVX group. Besides, our study also found that the RANK mRNA expression was down-regulated in OVX+PEMF group compared with OVX group. Taken together, we reported that long-term stimulation with PEMF treatment was able to alleviate lumbar vertebral OP in postmenopausal mice through a combination of increased bone formation and suppressed bone resorption related to regulating the skeletal gene expressions of Wnt3a/LRP5/β-catenin and OPG/RANKL/RANK signaling pathways.

Synthesis, characterization, and in vitro cytotoxicity of fatty acyl-CGKRK-chitosan oligosaccharides conjugates for siRNA delivery

In this studies, three fatty acyl derivatives of CGKRK homing peptides were coupled successfully to chitosan oligosaccharides (COS) using sulfosuccinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate sodium salt (sulfo-SMCC). The COS-SMCC was prepared by direct coupling between COS and sulfo-SMCC in PBS (pH7.5) at RT for 48h. The structure of COS-SMCC and the three fatty acyl-CGKRK-SMCC-COS conjugates were characterized by FT-IR, ¹³C NMR, and SEM. The ability of three conjugates to condense siRNA into nanosized polyplexes and their efficacy in protecting siRNA from serum nucleases degradation were investigated. Among the investigated derivatives, S-CGKRK-COS showed higher siRNA binding affinity as compared to the P-CGKRK-COS and O-CGKRK-COS, respectively. At a ratio of 10:1, complete protection for siRNA from early enzymatic degradation was achieved. The polymers and the polymer/siRNA polyplexes showed negligible cytotoxicity on human breast cancer cell line MDA-MB-231 at all investigated ratios. However, the polyplexes prepared with palmitoyl and oleoyl derivatives at polymer concentration 10μg/mL reduced the cell viability by 21.5% and 35%, respectively. The results of this study revealed the potential use of fatty acyl-CGKRK-COS as a siRNA carrier and confirmed the importance of incorporating a hydrophobic moiety into chitosan to improve its capacity in complexing with siRNA and protection from degradation.

The Effects of Biological Fluids on Colloidal Stability and siRNA Delivery of a pH-Responsive Micellar Nanoparticle Delivery System

Nanoparticles (NPs) interact with complex protein milieus in biological fluids, and these interactions have profound effects on NP physicochemical properties and function. Surprisingly, most studies neglect the impact of these interactions, especially with respect to NP-mediated siRNA delivery. Here, the effects of serum on colloidal stability and siRNA delivery of a pH-responsive micellar NP delivery system were characterized. Results show cationic NP-siRNA complexes aggregate in ≥2% serum in buffer, but are stable in serum-free media. Furthermore, nonaggregated NP-siRNA delivered in serum-free media result in 4-fold greater siRNA uptake in vitro, compared to aggregated NP-siRNA. Interestingly, pH-responsive membrane lysis behavior, which is required for endosomal escape, and NP-siRNA dissociation, necessary for gene knockdown, are significantly reduced in serum. Consistent with these data, nonaggregated NP-siRNA in serum-free conditions result in highly efficient gene silencing, even at doses as low as 5 nM siRNA. NP-siRNA diameter was measured at albumin and IgG levels mimicking biological fluids. Neither albumin nor IgG alone induces NP-siRNA aggregation, implicating other serum proteins in NP colloidal instability. Finally, as a proof-of-principle that stability is maintained in established in vivo models, transmission electron microscopy reveals NP-siRNA are taken up by ductal epithelial cells in a nonaggregated state when injected retroductally into mouse salivary glands in vivo. Overall, this study shows serum-induced NP-siRNA aggregation significantly diminishes efficiency of siRNA delivery by reducing uptake, pH-responsive membrane lysis activity, and NP-siRNA dissociation. Moreover, these results highlight the importance of local NP-mediated drug delivery and are broadly applicable to other drug delivery systems.