Blood circulating miRNAs as biomarkers of Alzheimer's disease: a systematic review and meta-analysis.

Aim: It is already known that miRNAs can be differentially expressed in Alzheimer's disease (AD). We aimed to evaluate the performance of miRNAs from blood as potential biomarkers for AD. Materials & methods: MEDLINE, PubMed and Embase were searched for studies about peripheral blood miRNAs that could discriminate patients with AD from cognitively normal controls. The data regarding the specificity and sensitivity were extracted. STATA 14.0 was used to analyze the data. Results: Ten studies containing 770 AD and 664 normal controls. The analysis showed that miRNAs presented excellent diagnostic performance and the overall sensitivity was 0.80 (95% CI: 0.75-0.83), specificity was 0.83 (95% CI: 0.78-0.87) and diagnostic odds ratio was 14 (95% CI: 11-19). Subgroup analysis suggested that the Caucasian group and blood group showed a better performance in AD diagnosis and the diagnostic odds ratio was 42 and 34, respectively. Conclusion: This meta-analysis showed that miRNAs may be a promising biomarkers for AD.

Acid-enhanced conformation changes of yeast cytochrome c coated onto gold nanoparticles, a FT-IR spectroscopic analysis.

Under conditions with or without linker molecules, the effects of acidic pH on the conformation of yeast iso-1-cytochrome c coated onto gold nanoparticles (AuNPs) in correlation with color changes of a Cyt c-coated AuNPs solution/suspension were examined by Fourier transform infrared (FT-IR) spectroscopy and correlated to color change. The results of detailed secondary structural analysis revealed that although the color changes coincide with acid-induced conformational changes in Cyt c coated onto AuNPs, the pH-related conformational unfolding of Cyt c coated onto AuNPs differed dramatically from that of its counterpart in solution. For Cyt c free in solution, the acid-induced unfolding did not occur until the pH was below 3.0, whereas for Cyt c coated onto AuNPs via C102 coordination near the C-terminal, a partial unfolding was observed even at near neutral pH which continuously intensified as pH decreased. Insertion of a short alkanethiol (3-mercaptoproprionic acid, 3-MPA) molecule between Cyt c and AuNP, which changes the interaction mode from a thiol coordination between Cyt c and AuNP to an electrostatic interaction between Cyt c and 3-MPA, which stabilized the conformation of Cyt c significantly, but did not prevent the acid-induced aggregation of Cyt c-3MPA-AuNPs.

Neuroprotective effect of lovastatin by inhibiting NMDA receptor1 in 6-hydroxydopamine treated PC12 cells.

In addition to original role of lowering cholesterol, statins display multiple neuroprotective mechanisms. In this study, 6-Hydroxydopamine (6-OHDA)-treated pheochromocytoma-12 (PC12) cells were used to investigate the neuroprotective nature of lovastatin. After incubation with 6-OHDA and/or lovastatin, test kits were used to detect the levels of LDH and glutamate, which were released from PC12 cells exposed to different culture media. The mRNA levels of TNF-α, and NMDAR1 were determined by RT-PCR and the protein levels were analyzed by western blot. Our results show that lovastatin significantly decreased both the mRNA and the protein levels of TNF-α and NMDAR1. ELISA assays revealed increased lactate dehydrogenase (LDH) and glutamate binding activity in 6-OHDA-lesioned PC12 cells, and this increase could be prevented by lovastatin. Our results suggest that lovastatin induces neuroprotection by inhibiting NMDAR1 and TNF-α. The data provide direct evidence of the potential application of lovastatin for the treatment of parkinson's diseases.

Association between plasma soluble P-selectin elements and progressive ischemic stroke.

The aim of this study was to analyze the association between plasma-soluble P-selectin (sP-selectin) elements and progressive ischemic stroke (PIS) and to explore the pathogenesis of PIS. Patients with acute ischemic stroke who were admitted and hospitalized in the Department of Neurology between August 2010 and August 2011 were used as subjects in this study. The enrolled patients were divided into progressive (58 cases) and non-progressive groups (143 cases), based on changes in disease conditions. The normal control group included 40 cases. The sP-selectin levels and related risk factors of the three groups of patients were compared. sP-selectin levels in the progressive group showed the highest values on day 1 after progression and gradually decreased on days 3, 7 and 14. sP-selectin levels in the progressive and non-progressive groups on day 1 were higher compared with those in the control group (P<0.05) and the levels in the progressive group were higher compared with those in the non-progressive group (P<0.05). On days 3 and 7, levels in the progressive group were higher compared with those in the non-progressive group (P<0.05) and on day 14, levels in the progressive group remained higher compared with those in the non-progressive group (P>0.05). On days 1, 3 and 7, sP-selectin levels in the aortic atherosclerosis progressive group were higher compared with those in the aortic atherosclerosis non-progressive group (P<0.05), however on day 14, the difference between the two groups was not statistically significant (P>0.05). P-selectin levels had the most significant impact on the progressive group and the aortic atherosclerosis progressive group. P-selectin levels were high in patients with PIS and even higher in the aortic atherosclerosis progressive group and were closely correlated with the onset time of PIS.

A systematic multitechnique approach for detection and characterization of reversible self-association during formulation development of therapeutic antibodies.

In addition to controlling typical instabilities such as physical and chemical degradations, understanding monoclonal antibodies' (mAbs) solution behavior is a key step in designing and developing process and formulation controls during their development. Reversible self-association (RSA), a unique solution property in which native, reversible oligomeric species are formed as a result of the noncovalent intermolecular interactions has been recognized as a developability risk with the potential to negatively impact manufacturing, storage stability, and delivery of mAbs. Therefore, its identification, characterization, and mitigation are key requirements during formulation development. Considering the large number of available analytical methods, choice of the employed technique is an important contributing factor for successful investigation of RSA. Herein, a multitechnique (dynamic light scattering, multiangle static light scattering, and analytical ultracentrifugation) approach is employed to comprehensively characterize the self-association of a model immunoglobulin G1 molecule. Studies herein discuss an effective approach for detection and characterization of RSA during biopharmaceutical development based on the capabilities of each technique, their complementarity, and more importantly their suitability for the stage of development in which RSA is investigated.

A systematic multitechnique approach for detection and characterization of reversible self-association during formulation development of therapeutic antibodies.

In addition to controlling typical instabilities such as physical and chemical degradations, understanding monoclonal antibodies' (mAbs) solution behavior is a key step in designing and developing process and formulation controls during their development. Reversible self-association (RSA), a unique solution property in which native, reversible oligomeric species are formed as a result of the noncovalent intermolecular interactions has been recognized as a developability risk with the potential to negatively impact manufacturing, storage stability, and delivery of mAbs. Therefore, its identification, characterization, and mitigation are key requirements during formulation development. Considering the large number of available analytical methods, choice of the employed technique is an important contributing factor for successful investigation of RSA. Herein, a multitechnique (dynamic light scattering, multiangle static light scattering, and analytical ultracentrifugation) approach is employed to comprehensively characterize the self-association of a model immunoglobulin G1 molecule. Studies herein discuss an effective approach for detection and characterization of RSA during biopharmaceutical development based on the capabilities of each technique, their complementarity, and more importantly their suitability for the stage of development in which RSA is investigated.

Calcium binding to a factor ix Fc fusion protein and effects on higher-order structure.

There is significant scope for more meaningful evaluation of higher-order structure in defining the quality of biopharmaceutical products [Bush L. 2010. Biopharm Int 23(4):14]. We have used isothermal titration calorimetry (ITC) to characterize the Ca(2+) -binding isotherm of a recombinant human factor IX Fc fusion protein (rFIXFc) and the parent recombinant human factor IX molecule (rFIX). Circular dichroism, intrinsic fluorescence, and Fourier transform infrared spectroscopies detected characteristic spectral changes that appear qualitatively consistent with the previously characterized behavior of the factor IX molecule. Sedimentation velocity and dynamic light scattering measurements were recorded in the presence and absence of Ca(2+) over the protein concentration range 1-10 mg/mL. ITC of Ca(2+) binding to rFIXFc reveals a distinctive exothermic-binding isotherm, which is interpreted as consistent with two high-affinity and approximately 14 lower-affinity Ca(2+) sites reported in the literature for human factor IX (Schmidt AE, Bajaj SP. 2003. Trends Cardiovasc Med 13(1):39-45). Analysis of accelerated degradation samples showed significant alterations in Ca(2+) binding, which correlates with significant loss of biopotency and fragmentation by gel chip capillary electrophoresis. Collectively, these data establish a close correspondence in the Ca(2+) -binding characteristics of rFIXFc and its parent rFIX molecule. The utility of ITC to provide a highly pertinent and selective biophysical signature of structure-function for a therapeutic factor protein is discussed.

Effects of immobilization onto aluminum hydroxide particles on the thermally induced conformational behavior of three model proteins.

Although the thermal unfolding/aggregation behavior of proteins in solution has been extensively studied, little is known about proteins immobilized on the surface of nanoparticles and other solid-phase materials. In this study we carefully monitor and analyze the thermal denaturation process of three model proteins adsorbed onto aluminum hydroxide as a function of temperature by FT-IR spectroscopy. The results reveal that the proteins immobilized onto aluminum hydroxide retain their native conformation at lower temperatures (<45 degrees C). Upon thermal denaturation, the structural transition between the native and denatured states is very similar, in terms of disappearance of the major native secondary structural elements, between the proteins adsorbed onto aluminum hydroxide adjuvant and in solution. This result suggests that the thermal stability of proteins is not significantly affected, or marginally affected at most, by the adsorption onto aluminum hydroxide adjuvant, considering a 5 degrees C temperature interval used for data collection. However, the adsorption rate and crowding of proteins on aluminum hydroxide particles have a profound effect on the aggregation behavior of the proteins, hydrogen bonding strength of intermolecular beta-sheet aggregates and conformation of intermediate states.

Wafer-scale patterning of sub-40 nm diameter and high aspect ratio (>50:1) silicon pillar arrays by nanoimprint and etching.

We demonstrate wide-area fabrication of sub-40 nm diameter, 1.5 µm tall, high aspect ratio silicon pillar arrays with straight sidewalls by combining nanoimprint lithography (NIL) and deep reactive ion etching (DRIE). Imprint molds were used to pre-pattern nanopillar positions precisely on a 200 nm square lattice with long range order. The conventional DRIE etching process was modified and optimized with reduced cycle times and gas flows to achieve vertical sidewalls; with such techniques the pillar sidewall roughness can be reduced below 8 nm (peak-to-peak). In some cases, sub-50 nm diameter pillars, 3 µm tall, were fabricated to achieve aspect ratios greater than 60:1.