High-density lipoprotein of patients with type 2 diabetes mellitus elevates the capability of promoting migration and invasion of breast cancer cells.

Epidemiological studies suggested complicated associations between type 2 diabetes mellitus and breast cancer. There is a significant inverse association between high-density lipoprotein (HDL) and the risk and mortality of breast cancer. However, HDL could be modified in various ways in diabetes patients, and this may lead to the altered effects on many different types of cells. In our study, we found that glycation and oxidation levels are significantly higher in HDL from type 2 diabetes mellitus patients compared to that from healthy subjects. Diabetic HDL dramatically had a stronger capability to promote cell proliferation, migration and invasion of breast cancer (as examined both on hormone-independent cells and on hormone-dependent cells). In addition, glycated and oxidized HDL, which were produced in vitro, acted in similar way as diabetic HDL. Diabetic HDL, glycated HDL and oxidized HDL also induced higher synthesis and secretion of VEGF-C, MMP-2 and MMP-9 from malondialdehyde (MDA)-MB-231 cells. It was indicated that diabetic, glycated and oxidized HDL promote MDA-MB-231 cell migration and invasion through ERK and p38 MAPK pathways, and Akt pathway plays an important role as well in MDA-MB-231 cell invasion. The Akt, ERK and p38 MAPK pathways are also involved in VEGF-C and MMP-9 secretion induced by diabetic, glycated and oxidized HDL. Our study demonstrated that glycation and oxidation of HDL in diabetic patients could lead to abnormal actions on MDA-MB-231 cell proliferation, migration and invasion, thereby promoting the progression of breast cancer. This will largely draw the attention of HDL-based treatments in diabetic patients especially those with breast cancer.

Loading solution prevents activation damage of human platelets before lyophilization.

The current study aims to optimize the compositions of platelet activation-inhibitors for a loading solution of lyophilizing protectants and to establish a series of perfect pretreatment methods for platelet lyophilization. The optimal combination of six kinds of inhibitors and loading solutions of lyophilizing protectants, including prostaglandin E1 (PGE1), adenosine, L-arginine, phyticacid, bivalirudin, and cilostazol, was analyzed using the orthogonal experimental design. The values of the expression rates of p-selectin (CD62p) and platelet membrane glycoprotein (PAC-1), as well as of platelet and mean platelet volume (MPV), were selected as indices of platelet activation. The values of CD62p and Pac-1 induced by thrombin were determined as indices of platelet reactivity. The maximal aggregation and slide platelet aggregation test (SPAT) induced by the inducer were calculated as indices of the aggregation function of platelets. Level I of the loading condition factor had no adverse action on MPV, CD62p, PAC-1, SPAT, and the maximum platelet aggregation rate. Level II of factors PGE1, L-arginine, phycicacid sodium, and Bivalirudin could inhibit the activation of platelets and enable them to retain their function. The results show that the optimal solution compounding was the third group. The loading solution, which includes plasma, 1 µM prostaglandin E1, 5 mM L-arginine, 0.5 mM phyticacid, and 0.5 µM bivalirudin, could prevent the activation damage of platelets before lyophilization.

Dual roles of SIRT1 in the BAX switch through the P53 module: A mathematical modeling study.

SIRT1 is a multifunctional deacetylase that participates in a variety of cellular physiological processes to cope with stress. The anticancer protein P53 is an important target of SIRT1. It has been found that SIRT1 is involved in apoptosis by regulating the activity and intracellular location of P53. Moreover, P53-dependent apoptosis is inseparable from the BCL-2 protein family. Among the members of this family, BAX's switching dynamics may play a key role in apoptosis. Therefore, a challenging question arises: what effect does SIRT1 have on the BAX switch? To answer this question, we built a small-scale protein network model. Through computer simulation, the properties of SIRT1 that on the one hand promote and on the other inhibit apoptosis are revealed. We found that the opening time of the BAX switch will be delayed in the case of either SIRT1 excess or deficiency. Similarly, the stimulus threshold required for apoptosis will also increase in the above two scenarios. Thereby, we proposed that SIRT1 has an optimal content at which the probability of apoptosis is greatest. In addition, P53 oscillation requires the concentration of SIRT1 to be higher than the optimal value. This work may be helpful both experimentally and clinically.

Electrokinetic energy conversion efficiency of viscoelastic fluids in a polyelectrolyte-grafted nanochannel.

In order to conduct extensive investigation of energy harvesting capabilities of nanofluidic devices, we provide analytical solutions for streaming potential and electrokinetic energy conversion (EKEC) efficiency through taking the combined consequences of soft nanochannel, a rigid nanochannel whose surface is covered by charged polyelectrolyte layer, and viscoelastic rheology into account. The viscoelasticity of the fluid is considered by employing the Maxwell constitutive model when the forcing frequency of an oscillatory driving pressure flow matches with the inverse of the relaxation time scale of a typical viscoelastic fluid. We compare the streaming potential and EKEC efficiency with those of a rigid nanochannel, having zeta potential equal to the electrostatic potential at the solid-polyelectrolyte interface of the soft nanochannels. Within the present selected parameter ranges, it is shown that the different peaks of maximal streaming potential and EKEC efficiency for the rigid nanochannel are larger than those for the soft nanochannel when forcing frequencies of the driving pressure gradient are close to resonating frequencies. However, more enhanced streaming potential and EKEC efficiency for a soft nanochannel can be found in most of the regions away from these resonant frequencies. Moreover, the influence of several dimensionless parameters on EKEC efficiency is discussed in detail. Finally, within the given parametric regions, the maximum efficiency at some resonant frequency obtained in present analysis is about 25%.

Alternating current electroosmotic flow in polyelectrolyte-grafted nanochannel.

In this work, we investigate the time periodic electroosmotic flow (EOF) of an electrolyte solution through a slit polyelectrolyte-grafted (PE-grafted) nanochannel under applied alternating current (AC) electrical field. The PE-grafted nanochannel is represented by a rigid surface covered by a polyelectrolyte layer (PEL) in a brush-like configuration. Under Debye-Hückel approximation, we obtain analytical solutions of electrical potential in decoupled regime of PE-grafted nanochannel, where the thickness of PEL is independent of the electrostatic effects triggered by polyelectrolyte charges. Based upon the electrical potential obtained above, we calculate EOF velocities with uniform and non-uniform drag coefficients for PE-grafted nanochannel and compare their results. The effects of pertinent dimensionless parameters on EOF velocity amplitude are discussed in detail. Moreover, the amplitude of EOF velocity in a PE-grafted nanochannel is compared with that in a rigid one. It is shown that larger EOF velocity and volume flow rate are found for a PE-grafted nanochannel. In addition, AC EOF velocity is further investigated. The oscillation of velocity reduces and is restricted within the region near the PEL-electrolyte interface for higher oscillating Reynolds number Re.

[Detection and analysis of CD271, CD133 and CD34 expressions in bone marrow cells by flow cytometry with three color fluorescence labelling].

This study was purposed to detect the expressions of CD271, CD133 and CD34, and to analyze the correlation of CD271 with CD133 and CD133 with CD34 expressions. The human bone marrow cells (BMCs) and mononucleated cells (MNCs) were detected by flow cytometry with CD45-PerCP, CD271-FITC, CD133-PE and CD34-FITC labelling according to different combinations of design, cells were located and selected repeatedly by FSC, SSC and CD45 after acquirement, then the expressions of CD271, CD133 and CD34 were detected by flow cytometry. The results showed that the expressions of CD271, CD133 and CD34 in BMCs were 0.16%, 0.20% and 0.43% respectively, while their expressions were 0.49%, 0.47% and 1.07% respectively after isolation of MNCs. The co-expressions of CD271(+)CD133(+) before and after isolation of MNCs were (0.02 +/- 0.01)% and (0.03 +/- 0.02)% respectively. The co-expression of CD133(+) and CD34(+) before and after isolation of MNCs were (0.18 +/- 0.11)% and (0.42 +/- 0.23)% respectively (p < 0.01); meanwhile about 90% of cells with CD133(+) expressed CD34 and 40% of cells with CD34(+) expressed CD133. It is concluded that the established method of detection using flow cytometry with three color fluorescence labelling can be used to detect expression of CD271, CD133 and CD34 in BMCs. The cells with CD271 are different from cells with CD133 and CD34, which suggests that the CD271 may be of important role in evaluating and guiding the clinical application of BM MSCs.

[Protective effects of DMSO on function of lyophilized human platelets].

This study was aimed to investigate the effects of DMSO on platelets during pre-treatment for lyophilization, including centrifugation, washing and loading trehalose. After pre-treatment for lyophilization, the expression of platelet membrane surface glycoprotein (GP) including CD62p and PAC-1 was analyzed by FCM before and after induction with thrombin, the mean platelet volume (MPV) and platelet maximal aggregation with several platelet inducers were investigated. The results showed that the expression rates of CD62p and PAC-1, as the platelet activation signs, increased and were 30.37% and 15.01% respectively in group without DMSO after pre-treatment. And their differences in comparison with control were statistically significant, but that of CD62p was 10.72% and PAC was 10.11% in group with DMSO, in comparison with group without DMSO respectively, their differences were statistically significant after diluting with DMSO, CD62p was re-expressed to 54.39% in group with DMSO and more than that in group without DMSO and lower than control statistically significant. PAC-1 was re-expressed to 49.28% in group with DMSO and more than that in group without DMSO (p<0.01) and reached to control. Platelet maximal aggregations induced by thrombin, restocetin and propyl gallate were 92.76%, 91.24% and 89.66 respectively in group with DMSO. These were closed to that in control group and in group without DMSO. But the aggregation induced by ADP was 34.33%, it was less than control (p<0.01) and more than that in group without DMSO (p<0.01). It is concluded that DMSO can inhibit the expression of CD62p and PAC-1 on platelet in vitro. But when diluted with plasma, platelets can express CD62p and PAC-1 induced by thrombin and be led to aggregate by several inducers, so the inhibitory effects of DMSO on platelet activation are reversible. DMSO play roles in inhibitor damage from platelet activation and cryoprotectant. This property of DMSO is very important in research of platelets lyophilization.