Mass spectrometry based investigation of Alzheimer’s disease and its biomarkers

The overall aim of this work was to find biomarkers for Alzheimer’s disease (AD) in such an easily accessible body fluid as blood and investigate the implications of these biomarkers for the AD mechanism. The central and most studied histopathological features in AD brain are the amyloid plaques. Even at the preclinical stage of AD, amyloid beta (Aβ) peptides already start to form plagues. It still remains unclear whether Aβ oligomers and fibrils initiate the molecular cascade that ultimately leads to AD. So far, all Aβ-centered therapy approaches have had little success. Therefore, a fresh, unorthodox look at the AD initiation and biomarkers of the disease development is required. Since the primary risk factor for AD is age, biomarkers of protein aging could hypothetically be linked to AD. One of the main protein aging pathways is isoaspartate (isoAsp) accumulation; increased isoAsp levels are found in AD amyloid plaques. Thus we developed a mass spectrometry-based platform and workflow for isoAsp detection and quantification (Paper I), and applied them for the analysis of blood plasma samples from AD patients and healthy controls. We found increased levels of isoAsp in all stages of dementia (Paper II), which supported the hypothetical mechanism in which isoAsp accumulation triggers a sequence of events resulting in AD. To further investigate the impact of isoAsp accumulation in the central nervous system, we analyzed the brains of the transgenic mouse model lacking isoAsp repair via methylation (Paper III), and found that, along with the increased isoAsp levels, glutamate pathway is seriously distorted. IsoAsp can be cleared from the organism, besides repair, by means of proteases. When analyzing protein abundances in blood, we found links between these protein functions and AD development (Paper IV). The changes in the protein abundances were small, but nevertheless predictive of the AD progression. How early can one detect the imminent AD development by protein biomarkers? To address this question in the best possible scenario (a well-controlled system, brain biopsy), we analyzed the brain proteome of young transgenic mice and found statistically significant changes occurring long before the onset of AD-like symptoms (Paper V). Therefore, protein abundances, together with isoAsp levels, are promising biomarker candidates for AD diagnostics and prognostics, and mass spectrometry is an adequate tool for analyzing them

Evolution of a domain conserved in microtubule-associated proteins of eukaryotes

The microtubule network, the major organelle of the eukaryotic cytoskeleton, is involved in cell division and differentiation but also with many other cellular functions. In plants, microtubules seem to be involved in the ordered deposition of cellulose microfibrils by a so far unknown mechanism. Microtubule-associated proteins (MAP) typically contain various domains targeting or binding proteins with different functions to microtubules. Here we have investigated a proposed microtubule-targeting domain, TPX2, first identified in the Kinesin-like protein 2 in Xenopus. A TPX2 containing microtubule binding protein, PttMAP20, has been recently identified in poplar tissues undergoing xylogenesis. Furthermore, the herbicide 2,6-dichlorobenzonitrile (DCB), which is a known inhibitor of cellulose synthesis, was shown to bind specifically to PttMAP20. It is thus possible that PttMAP20 may have a role in coupling cellulose biosynthesis and the microtubular networks in poplar secondary cell walls. In order to get more insight into the occurrence, evolution and potential functions of TPX2-containing proteins we have carried out bioinformatic analysis for all genes so far found to encode TPX2 domains with special reference to poplar PttMAP20 and its putative orthologs in other plants

Comparative Evaluation of Light-emitting Diode (LED) vs. Fluorescent (FL) Lighting in Commercial Aviary Hen Houses

In this ongoing study, indoor environment, production performance, egg quality, and some welfare aspects of laying hens in two commercial aviary houses installed with light-emitting diode (LED) lights are compared with those in two aviary houses of similar hen age with fluorescent (FL) lights. To date the study (covering 18 – 44 weeks of hen age) shows the following preliminary results. The daily mean temperature and relative humidity (RH) in all houses were generally maintained within 20-25°C and 50-80%, respectively. The holders of LED and FL light bulbs had similar temperatures, approximately 40°C. There were no significant differences in hen production performance parameters between the LED and FL houses. Egg weight, yolk weight, yolk percentage and yolk color factor increased as hen age increased. The Haugh unit (HU) values of fresh eggs in all four houses at 27 and 40 weeks of age were 90 or higher, i.e., much greater than the “AA grade” egg threshold of 72. Haugh unit of fresh eggs in FL houses did not change over age, however, HU significantly decreased from 93.5±0.26 at 27 weeks of age to 91.6±0.35 at 40 weeks of age in LED houses (P\u3c0.05). Compared to FL, LED improved egg weight, albumen height, HU, yolk weight and albumen weight at 27 weeks of age, and improved shell strength at 40 weeks of age (P\u3c0.05). Dust accumulation rate (DAR) in LED houses (245±17 mg[hen-day]-1 or 3855±273 mg[m2 -day]-1) and FL houses (278±22 mg[hen-day]-1 or 4366±352 mg[m2 -day]-1) were similar. Hens in LED houses tended to have worse back/rump feather conditions than hens in FL houses. Median avoidance distance of hens to human approach was 3.55 m and 3.20 m, respectively, in LED and FL houses. More data collection is continuing

Successful Remove of a Metal Axletree Causing Penile Strangulation in a 19-Year-Old Male by Degloving Operation

Penile strangulation caused by foreign bodies mostly occurs in adolescents and adult males. When it happens, foreign bodies are often not easy to be removed. Penile strangulation is a rarely described urological emergency, especially in the adolescent population. This paper demonstrates the successful removal of a metal axletree causing penile strangulation in a 19-year-old male with the help of degloving operation

TGFβƒ1 Promotes Gemcitabine Resistance Through Regulating the LncRNA-LET/NF90/miR-145 Signaling Axis in Bladder Cancer

High tumor recurrence is frequently observed in patients with urinary bladder cancers (UBCs), with the need for biomarkers of prognosis and drug response. Chemoresistance and subsequent recurrence of cancers are driven by a subpopulation of tumor initiating cells, namely cancer stem-like cells (CSCs). However, the underlying molecular mechanism in chemotherapy-induced CSCs enrichment remains largely unclear. In this study, we found that during gemcitabine treatment lncRNA-Low Expression in Tumor (lncRNA-LET) was downregulated in chemoresistant UBC, accompanied with the enrichment of CSC population. Knockdown of lncRNA-LET increased UBC cell stemness, whereas forced expression of lncRNA-LET delayed gemcitabine-induced tumor recurrence. Furthermore, lncRNA-LET was directly repressed by gemcitabine treatment-induced overactivation of TGFβ/SMAD signaling through SMAD binding element (SBE) in the lncRNA-LET promoter. Consequently, reduced lncRNA-LET increased the NF90 protein stability, which in turn repressed biogenesis of miR-145 and subsequently resulted in accumulation of CSCs evidenced by the elevated levels of stemness markers HMGA2 and KLF4. Treatment of gemcitabine resistant xenografts with LY2157299, a clinically relevant specific inhibitor of TGFβRI, sensitized them to gemcitabine and significantly reduced tumorigenecity in vivo. Notably, overexpression of TGFβ1, combined with decreased levels of lncRNA-LET and miR-145 predicted poor prognosis in UBC patients. Collectively, we proved that the dysregulated lncRNA-LET/NF90/miR-145 axis by gemcitabine-induced TGFβ1 promotes UBC chemoresistance through enhancing cancer cell stemness. The combined changes in TGFβ1/lncRNA-LET/miR-145 provide novel molecular prognostic markers in UBC outcome. Therefore, targeting this axis could be a promising therapeutic approach in treating UBC patients

Image-guided percutaneous renal cryoablation for stage 1 renal cell carcinoma with high surgical risk

Background: This study was undertaken to evaluate the feasibility, safety, and therapeutic effects of percutaneous renal cryoablation under local anesthesia with conscious sedation for patients who have unresectable stage 1 (T1NoMo) renal cell carcinoma (RCC) in high surgical risk. Methods: Eighteen patients who were not candidates for surgery underwent primary cryosurgery guided by gray-scale ultrasound. Contrast-enhanced ultrasonography (CEUS) and contrast-enhanced computed tomography (CT) were performed to evaluate treatment at completion. Results: The mean follow-up period was 26.8 months (range, 12–56 months). All tumors were biopsied before cryosurgery. Seventeen tumors remained free of enhancement during follow-up period. No major complications associated with cryoablation procedures were found though two instances of subcapsular hematomas, one of retroperitoneal errhysis and one of nausea, were seen after cryoablation. One patient had a local recurrence of tumor and received additional cryoablation. Local tumor control rate was 100 % of T1NoMo tumors including the recurrence case who underwent additional cryoablation. Conclusions: Percutaneous cryoablation can be recommended as a feasible, safe, and promising therapy for the treatment of renal tumor, especially those unresectable stage 1 RCC, with a low risk of complications

Early life relict feature in peptide mass distribution

The molecular mass of a biomolecule is characterized by the monoisitopic mass Mmono and the average isotopic mass Mav. We found that tryptic peptide masses mapped on a plane made by two parameters derived from Mmono and Mav form a peculiar feature in the form of a 'band gap' stretching across the whole 'peptide galaxy', with a narrow line in the centre. The purpose of this study was to investigate possible reasons for the emergence of such a feature, provided it is not a random occurrence. The a priori probability of such a feature to emerge by chance was found to be less than 1:100. Peptides contributing to the central line have elemental compositions following the rules S = 0; Z = C - (N + H)/2 = 0, which nine out of 20 amino acid residues satisfy. The relative abundances of amino acids in the peptides contributing to the central line correlate with the consensus order of emergence of these amino acids, with ancient amino acids being overrepresented in on-Line peptides. Since linear correlation between Mav and Mmono reduces the complexity of polypeptide molecules, and the turnover rate of less complex molecules should be faster in non-equilibrium abiotic synthesis, we hypothesize that the line could be a signature of abiotic production of primordial biopolymers. The linear dependence between the average isotopic masses and monoisotopic masses may have influenced the selection of amino acid residues for terrestrial life. © 2010 Versita Warsaw and Springer-Verlag Berlin Heidelberg.link_to_subscribed_fulltex

Targeting MHC-I molecules for cancer: function, mechanism, and therapeutic prospects

Abstract The molecules of Major histocompatibility class I (MHC-I) load peptides and present them on the cell surface, which provided the immune system with the signal to detect and eliminate the infected or cancerous cells. In the context of cancer, owing to the crucial immune-regulatory roles played by MHC-I molecules, the abnormal modulation of MHC-I expression and function could be hijacked by tumor cells to escape the immune surveillance and attack, thereby promoting tumoral progression and impairing the efficacy of cancer immunotherapy. Here we reviewed and discussed the recent studies and discoveries related to the MHC-I molecules and their multidirectional functions in the development of cancer, mainly focusing on the interactions between MHC-I and the multiple participators in the tumor microenvironment and highlighting the significance of targeting MHC-I for optimizing the efficacy of cancer immunotherapy and a deeper understanding of the dynamic nature and functioning mechanism of MHC-I in cancer

Niosome-Assisted Delivery of DNA Fluorescent Probe with Optimized Strand Displacement for Intracellular MicroRNA21 Imaging

MicroRNAs play a vital role in cancer development and are considered as potential biomarkers for early prognostic assessment. Here, we propose a novel biosensing system to achieve fluorescence imaging of miRNA21 (miR21) in cancer cells. This system consists of two components: an optimized “off-on” double-stranded DNA (dsDNA) fluorescent for miR21 sensing by efficient strand-displacement reaction and a potent carrier vesicle, termed niosome (SPN), to facilitate the efficient intracellular delivery of the dsDNA probe. A series of dsDNA probes based on fluorescence energy resonance transfer (FRET) was assembled to target miR21. By optimizing the appropriate length of the reporter strand in the dsDNA probe, high accuracy and sensitivity for miR21 recognition are ensured. To overcome the cellular barrier, we synthesized SPN with the main components of a nonionic surfactant Span 80 and a cationic lipid DOTAP, which could efficiently load dsDNA probes via electrostatic interactions and potently deliver the dsDNA probes into cells with good biosafety. The SPN/dsDNA achieved efficient miR21 fluorescent imaging in living cells, and could discriminate cancer cells (MCF-7) from normal cells (L-02). Therefore, the proposed SPN/dsDNA system provides a powerful tool for intracellular miRNA biosensing, which holds great promise for early cancer diagnosis