Biomedical subjects

Liang Li

Publications and source records attributed to Liang Li.

At least 109 records · Page 6Linked to original sources

PubMed2004

Open tubular immobilized metal ion affinity chromatography combined with MALDI MS and MS/MS for identification of protein phosphorylation sites.

Protein phosphorylation is one of the most important known posttranslational modifications. Tandem mass spectrometry has become an important tool for mapping out the phosphorylation sites. However, when a peptide generated from the enzymatic or chemical digestion of a phosphoprotein is highly phosphorylated or contains many potential phosphorylation residues, phosphorylation site assignment becomes difficult. Separation and enrichment of phosphopeptides from a digest mixture is desirable and often a critical step for MS/MS-based site determination. In this work, we present a novel open tubular immobilized metal ion affinity chromatography (OT-IMAC) method, which is found to be more effective and reproducible for phosphopeptide enrichment, compared to a commonly used commercial product, Ziptip from Millipore. A strategy based on a combination of OT-IMAC, sequential dual-enzyme digestion, and matrix-assisted laser desorption/ionization (MALDI) quadrupole time-of-flight tandem mass spectrometry for phosphoprotein characterization is presented. It is shown that MALDI MS/MS with collision-induced dissociation can be very effective in generating fragment ion spectra containing rich structural information, which enables the identification of phosphorylation sites even from highly phosphorylated peptides. The applicability of this method for real world applications is demonstrated in the characterization and identification of phosphorylation sites of a Na(+)/H(+) exchanger fusion protein, His182, which was phosphorylated in vitro using the kinase Erk2.

Journal Article↗

PubMed2004

Characteristics of selenazolidine prodrugs of selenocysteine: toxicity, selenium levels, and glutathione peroxidase induction in A/J mice.

We have previously reported the synthesis and characterization of two new classes of selenazolidine-4(R)-carboxylic acids (2-oxo and 2-methyl-SCAs) (OSCA and MSCA, respectively), as well as the "parent" compound, selenazolidine-4(R)-carboxylic acid (SCA, selenaproline). These compounds were designed as prodrugs of L-selenocysteine with potential application in cancer chemoprevention or other clinical uses. We will be exploring the chemopreventive activity of the new compounds in the well-established A/J mouse model of tobacco-induced lung carcinogenesis. The objectives of the present study were to investigate several fundamental biochemical endpoints after selenazolidine administration compared with other selenium-containing agents. Groups of mice were fed either AIN-76A diet alone or the diet supplemented with the following selenium compounds (ppm Se): sodium selenite (5), L-selenomethionine (3.75), L-selenocystine (15), Se-methyl-L-selenocysteine (3), MSCA (5, 10, or 15), OSCA (5, 10, or 15), or SCA (5, 10, or 15). After 28 days of supplementation, toxicity of the selenazolidines was not evident, as measured by outward appearance and behavior, body and organ weight changes, and histological evaluation of liver and lung tissue. Select treatment groups showed significant increases in selenium levels in blood and tissues. Increased activity of selenium-dependent glutathione peroxidase (GPx) in blood and liver illustrated that the selenazolidines provided a source of biologically-available selenium.

Animals↗

PubMed2004

Memantine inhibits and reverses the Alzheimer type abnormal hyperphosphorylation of tau and associated neurodegeneration.

Memantine, an N-methyl-D-aspartate (NMDA) receptor antagonist, reduces the clinical deterioration in moderate-to-severe Alzheimer disease (AD) for which other treatments are not available. The activity of protein phosphatase (PP)-2A is compromised in AD brain and is believed to be a cause of the abnormal hyperphosphorylation of tau and the consequent neurofibrillary degeneration. Here we show that memantine inhibits and reverses the PP-2A inhibition-induced abnormal hyperphosphorylation and accumulation of tau in organotypic culture of rat hippocampal slices. Such restorative effects of memantine were not detected either with 5,7-dichlorokynurenic acid or with D(-)-2-amino-5-phosphopentanoic acid, NMDA receptor antagonists active at the glycine binding site and at the glutamate binding site, respectively. These findings show (1) that memantine inhibits and reverses the PP-2A inhibition-induced abnormal hyperphosphorylation of tau/neurofibrillary degeneration and (2) that this drug might be useful for the treatment of AD and related tauopathies.

2-Amino-5-phosphonovalerate↗

PubMed2004

Chemical waves with line defects in the Belousov-Zhabotinsky reaction.

We report our experimental observations of line-defected chemical waves in a quasi-two-dimensional reaction-diffusion system of Belousov-Zhabotinsky reaction. The observed line defects are explicit, which can be directly monitored in real time. In the parameter space, the state of the chemical waves with line defects is located between two regimes of the defect-mediated turbulence. The line defects appear in target waves as well as in spiral waves. We demonstrate that the line defects come out in traveling waves as the later reorganize their spatial topologies to adapt to the change in the local dynamics from simple to complex oscillations or vice versa.

Journal Article↗

PubMed2004

Identification of bacteria using tandem mass spectrometry combined with a proteome database and statistical scoring.

Detection and identification of pathogenic bacteria and their protein toxins play a crucial role in a proper response to natural or terrorist-caused outbreaks of infectious diseases. The recent availability of whole genome sequences of priority bacterial pathogens opens new diagnostic possibilities for identification of bacteria by retrieving their genomic or proteomic information. We describe a method for identification of bacteria based on tandem mass spectrometric (MS/MS) analysis of peptides derived from bacterial proteins. This method involves bacterial cell protein extraction, trypsin digestion, liquid chromatography MS/MS analysis of the resulting peptides, and a statistical scoring algorithm to rank MS/MS spectral matching results for bacterial identification. To facilitate spectral data searching, a proteome database was constructed by translating genomes of bacteria of interest with fully or partially determined sequences. In this work, a prototype database was constructed by the automated analysis of 87 publicly available, fully sequenced bacterial genomes with the GLIMMER gene finding software. MS/MS peptide spectral matching for peptide sequence assignment against this proteome database was done by SEQUEST. To gauge the relative significance of the SEQUEST-generated matching parameters for correct peptide assignment, discriminant function (DF) analysis of these parameters was applied and DF scores were used to calculate probabilities of correct MS/MS spectra assignment to peptide sequences in the database. The peptides with DF scores exceeding a threshold value determined by the probability of correct peptide assignment were accepted and matched to the bacterial proteomes represented in the database. Sequence filtering or removal of degenerate peptides matched with multiple bacteria was then performed to further improve identification. It is demonstrated that using a preset criterion with known distributions of discriminant function scores and probabilities of correct peptide sequence assignments, a test bacterium within the 87 database microorganisms can be unambiguously identified.

Algorithms↗

PubMed2004

Combining liquid chromatography with MALDI mass spectrometry using a heated droplet interface.

A novel interfacing technology is described to combine solution-based separation techniques such as liquid chromatography (LC) with matrix-assisted laser desorption ionization (MALDI) mass spectrometry. The interface includes a transfer tube having an inlet and an outlet, the inlet being adapted to accept the LC effluents and the outlet being adapted to form continuously replaced, hanging droplets of the liquid stream, and a MALDI sample plate mounted below the outlet of the transfer tube for collecting the droplets. The liquid stream in the transfer tube is heated to a temperature sufficient to cause partial evaporation of the carrier solvent from the hanging droplets. The droplets are dislodged to the MALDI plate, which is heated to above the boiling point of the carrier solvent to cause further evaporation of the carrier solvent from the collected droplets. It is found that analytes can be fractionated and deposited to a sample spot of 0.8 mm in diameter when a liquid flow rate of up to 50 microL/min and a fractionation interval of 1 min/spot are used. Flow rate of up to 200 microL/min can be used with a deposition sample spot of 2.4 mm in diameter on a commercial MALDI target. This heated droplet interface does not introduce sample loss, and the detection sensitivity of LC/MALDI is similar to that of standard MALDI, i.e., low femtomoles for peptide analysis with a microliter sample deposition. It is compatible with microbore and narrow-bore column separation, thus allowing the injection of a larger amount of sample for separation and analysis, compared to a capillary column LC/MALDI system. The detection dynamic range is shown to be in the order of 10(6) for peptide mixture analysis, which is 4 orders of magnitude greater than standard MALDI. The application of this interface for combining LC with MALDI MS/MS is demonstrated in the proteome analysis of water-soluable protein components of E. coli K12 extracts.

Chromatography, Liquid↗

PubMed2004

Gender- and age-specific impairment of rat performance in the Morris water maze following prenatal exposure to an MRI magnetic field.

We examined the effects of prenatal exposure (40 min/day, gestation days 12-18) of rats to a magnetic resonance imaging (MRI) magnetic field (MF) on their performance in the Morris water maze. At 2 months of age, female rats showed impaired performance. The animals spent longer time swimming and used inefficient strategies. However, no significant effects on maze performance were observed at 1 and 5 months of age. No evident maze performance deficit was detected in male rats prenatally exposed to the magnetic field. Thus, we conclude that prenatal exposure to MRI magnetic field induces cognitive/behavioral deficits in female rats at a specific age.

Age Factors↗

PubMed2004

Lipid raft proteomics: analysis of in-solution digest of sodium dodecyl sulfate-solubilized lipid raft proteins by liquid chromatography-matrix-assisted laser desorption/ionization tandem mass spectrometry.

Lipid rafts are glycolipid- and cholesterol-enriched membrane microdomains implicated in membrane signaling and trafficking. The highly hydrophobic nature of lipid raft proteins pose significant problems of solubilization and recovery that hinder analysis by mass spectrometry (MS) and may under-report the composition of lipid rafts. In a previous investigation of the monocyte lipid raft in which proteins were digested with trypsin following polyacrylamide gel electrophoresis we identified 52 proteins. Here we report the development of a sodium dodecyl sulfate (SDS)-aided approach in which proteins are digested in solution and examined by high-performance liquid chromatography-matrix-assisted laser desorption/ionization-tandem mass spectrometry (HPLC-MALDI-MS/MS) using a novel LC-MALDI interface thereby circumventing the need to separate proteins on gels. Using this approach we identified 71 proteins in the lipid raft, 45 of which were not detected using in-gel digestion. Among the new proteins are alpha- and beta-tubulin, tubulinspecific chaperone A, a folding protein involved in tubulin dimer assembly, and KIF13, a microtubule motor protein indicating that proteins involved in microtubule assembly and trafficking are more readily detected using an in-solution approach. To investigate why tubulin was not identified by in-gel digestion, we compared the distribution of alpha-tubulin and the raft marker flotillin-2 in buoyant density gradients before and after separation on SDS-gels. Both proteins were present in the raft fractions, but tubulin was selectively lost following separation on SDS-gels. Assemblies of cytoskeletal proteins with lipid rafts may therefore be resolved using in-solution digestion that would be missed using gel-based approaches.

Biological Transport↗

PubMed2004

Effects of common surfactants on protein digestion and matrix-assisted laser desorption/ionization mass spectrometric analysis of the digested peptides using two-layer sample preparation.

While surfactants are commonly used in preparing protein samples, their presence in a protein sample can potentially affect the enzymatic digestion process and the subsequent analysis of the resulting peptides by mass spectrometry. The extent of the tolerance of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to surfactant interference in peptide analysis is very much dependent on the matrix/sample preparation method. In this work the effects of four commonly used surfactants, namely n-octyl glucoside (OG), Triton X-100 (TX-100), 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) and sodium dodecyl sulfate (SDS), for biological sample preparation on trypsin digestion and MALDI-MS of the resulting digest are examined in detail within the context of using a two-layer method for MALDI matrix/sample preparation. Non-ionic and mild surfactants, such as OG, TX-100 or CHAPS, are found to have no significant effect on trypsin digestion with surfactant concentrations up to 1%. However, TX-100 and CHAPS interfere with the subsequent peptide analysis by MALDI-MS and should be removed prior to peptide analysis. OG is an MS-friendly surfactant and no effect is observed for MALDI peptide analysis. The effect of SDS on trypsin digestion in terms of the number of peptides generated and the overall protein sequence coverage by these peptides is found to be protein dependent. The use of SDS to solubilize hydrophobic membrane proteins, followed by trypsin digestion in the presence of 0.1% SDS, results in a peptide mixture that can be analyzed directly by MALDI-MS. These peptides are shown to provide better sequence coverage compared with those obtained without the use of SDS in the case of bacteriorhodopsin, a very hydrophobic transmembrane protein. This work illustrates that MALDI-MS with the two-layer sample preparation method can be used for direct analysis of protein digests with no or minimum sample cleanup after proteins are digested in a solution containing surfactants.

Animals↗

PubMed2004

Unloaded shortening velocity in single permeabilized vascular smooth muscle cells is independent of microtubule status.

Microtubules may influence smooth muscle contraction either via involvement in signal transduction processes or by serving as an internal load that opposes contraction. To test the latter hypothesis, microtubule distribution and the unloaded shortening velocity were investigated in freshly isolated single vascular smooth muscle cells (VSMCs) treated with microtubule modulating drugs. Immunocytochemical studies showed that microtubules run mainly longitudinally in relaxed VSMCs. They are oriented more obliquely, almost transversely to the long axis of the cells after contraction, suggesting that microtubules are compressed during shortening, and thus might impart an internal passive load. Quantitative immunocytochemical analysis revealed that, relative to the control group, colchicine (15 microM) decreased the microtubule density by 40% while taxol (10 microM) increased the microtubule density by 46%. However, alteration of microtubule polymerization status by these microtubule-modulating drugs did not have a significant effect on unloaded shortening velocity in alpha-toxin permeabilized VSMCs under maximal activating conditions or submaximal activating conditions (about 36% of maximal velocity). These results suggest that microtubules do not present an appreciable internal load to dampen single VSMCs shortening in the present experimental system, and that their influence on smooth muscle contraction is primarily via signal transduction mechanisms.

Actins↗

PubMed2004

Does the information content of an irrelevant source differentially affect spoken word recognition in younger and older adults?

To determine whether older adults find it difficult to inhibit the processing of irrelevant speech, the authors asked younger and older adults to listen to and repeat meaningless sentences (e.g., "A rose could paint a fish") when the perceived location of the masker (speech or noise) but not the target was manipulated. Separating the perceived location (but not the physical location) of the masker from the target speech produced a much larger improvement in performance when the masker was informational (2 people talking) than when the masker was noise. However, the size of this effect was the same for younger and older adults, suggesting that cognitive-level interference from an irrelevant source was no worse for older adults than it was for younger adults.

Adult↗

PubMed2004

Keratinocyte-releasable stratifin functions as a potent collagenase-stimulating factor in fibroblasts.

Termination of wound healing requires a fine balance between collagen deposition and its hydrolysis. To dissect the underlying control mechanisms for this process, we established a keratinocyte/fibroblast co-culture system and subsequently demonstrated more than a 10-fold increase in collagenase expression in fibroblasts co-cultured with keratinocytes relative to that of control cells. This finding was further confirmed in fibroblasts grown in a keratinocyte/fibroblast collagen-GAG gel. The efficacy of keratinocyte-derived collagenase stimulatory factors on collagenase activity was evaluated, and the results showed that only conditioned medium derived from fibroblasts co-cultured with keratinocytes was able to break down markedly type I collagen to its one-quarter and three-quarter fragments of both alpha (alpha1 and alpha2) and beta (beta1.1 and beta1.2) chains. The results of a dose-response experiment showed that keratinocyte-conditioned medium (KCM) stimulates the expression of collagenase mRNA by dermal fibroblasts in a concentration-dependent fashion. In a similar experiment, the results of a time-response experiment revealed that KCM treatment increases the expression of collagenase mRNA in dermal fibroblasts as early as 6 h and reaches its maximum level within 24-48 h. Considering that this keratinocyte-releasable factor has a potent collagenase stimulatory effect on fibroblasts, which favors the resolution of accumulated type I and type III collagen found in fibrotic tissue, we referred to this protein as a keratinocyte-derived anti-fibrogenic factor (KDAF). In a series of chromatography experiments and a direct trypsin digestion of the proteins and subsequent peptide mapping, a keratinocyte-derived collagenase-stimulating factor turned out to be a releasable form of stratifin, also known as 14-3-3 sigma protein. To validate this finding, stratifin cDNA was cloned into a pGEX-6P-1 expressing vector and more than 50 mg of recombinant stratifin was generated and used to treat fibroblasts with various concentrations for 24 h. The results of northern analysis showed a remarkable dose-response increase in the expression of collagenase mRNA in stratifin-treated fibroblasts relative to that of the control. This finding was consistent with that obtained from collagenase activity assay. In conclusion, we identified a keratinocyte-releasable form of stratifin in KCM that mimics the collagenase stimulatory effect of KCM for dermal fibroblasts. This finding suggests that stratifin is likely to be, at least, one of the KDAFs found in KCM.

14-3-3 Proteins↗

PubMed2004

Dephosphorylation of microtubule-associated protein tau by protein phosphatase 5.

Protein phosphatase 5 (PP5) is a 58-kDa novel phosphoseryl/phosphothreonyl protein phosphatase. It is ubiquitously expressed in all mammalian tissues examined, with a high level in the brain, but little is known about its physiological substrates. We found that this phosphatase dephosphorylated recombinant tau phosphorylated with cAMP-dependent protein kinase and glycogen synthase kinase-3beta, as well as abnormally hyperphosphorylated tau isolated from brains of patients with Alzheimer's disease. The specific activity of PP5 toward tau was comparable to those reported with other protein substrates examined to date. The PP5 activity toward tau was stimulated by arachidonic acid by 30- to 45-fold. Immunostaining demonstrated that PP5 was primarily cytoplasmic in PC12 cells and in neurons of postmortem human brain tissue. A small pool of PP5 associated with microtubules. Expression of active PP5 in PC12 cells resulted in reduced phosphorylation of tau, suggesting that PP5 can also dephosphorylate tau in cells. These results suggest that PP5 plays a role in the dephosphorylation of tau and might be involved in the molecular pathogenesis of Alzheimer's disease.

Animals↗

PubMed2004

[Preparation of drug-loaded polylactic acid nanospheres and drug-releasing performance evaluation].

The polylactic acid (PLA) nanospheres containing griseofulvin were prepared by a water-in-oil solvent evaporation method adopting an uniformly designed experiment, and the drug-releasing rates were compared between the microsphere and nanosphere. The results showed that the nanospheres was good in spherical shape with narrow distribution of the particle sizes. The particle diameter was about 114 nm, and the comprehensive score of the nanosphere was 95.59, with the error of 3.66% and the drug content of 13.55% by the linearity regression averaged from the results of the three repeat experiments. The drug-releasing rate of the microsphere was relatively slow, while that of the nanosphere can have an abrupt increase, indicating its function of solubilizing the drug.

Drug Delivery Systems↗

PubMed2004

[Correlative changes of histomorphometry and biomechanical property of lumbar vertebrae body in ovariectomized rats].

This paper presents the correlative changes of cancellous bone histomorphometry, biomechanical property and bone mineral contents of lumbar vertebrae in ovariectomized rats. Forty eight 10.5-month-old female SD rats were randomized to six groups: 1) Basal: at 10.5 mon. of age; 2) sham-1: sham-operated at 13 mon. of age; 3) OVX-1: ovariectomized at 13 mon. of age; 4) sham-2: sham-operated at 16 mon. of age; 5) OVX-2: ovariectomized at 16 mon. of age; and 6) OVX-2 + EE: ovariectomized and treated with 17 alpha-ethynylestradiol (100 micrograms.kg-1.d-1) starting at 13 mon. of age for 12 weeks. Double in vivo fluorochrome labeling was administered to all rats. At the end-point of study, the undecalcified longitudinal fourth lumbar vertebra (LV4) sections were cut and stained with Goldner's Trichrome for bone histomorphometric analyses. The mechanical properties of the compact fifth lumbar vertebra body (LV5) were measured with compression test, the LV5 bodies then were dried constantly with high temperature and digested with acid for testing of bone mineral content. A trend in trabecular bone volume (BV/TV), trabecular thickness (Tb.Th) of LV4, bone break load, break stress, elastic moduli and bone calcium content of LV5 to increase with the increase of age was revealed in the intact rats, but the highest value was at 13 mon. of age. A positive correlation was seen between histomophormetry and bone bio-mechanical properties in the intact rats. Compared with the data from the sham-operated rats, the BV/TV and Tb. Th significantly decreased and bone turnover rate significantly increased in OVX rats at 10 weeks, and the above parameters further decreased 22 weeks post OVX. Correspondingly, the bone break load, break stress, elastic moduli and bone calcium content significantly decreased with the increase of time post OVX was compared with those of sham-operated rats. A positive correlation between histomophormetry and bone biomechanical properties was also observed in OVX rats (r = 0.399, P = 0.018). Bone histomorphometry is good for predicting early physiological and pathological changes and bone biomechanical properties are good parameters for predicting corresponding function of bone such as fracture. Both of them are useful and needful in the animal studies on osteoporosis and related pharmacodynamic observations on new drugs.

Animals↗

PubMed2004

[Effect of titanium particles loading on the viability of mesenchymal stem cells after osteoblastic induction].

OBJECTIVE: To assess the effect of titanium particles on the proliferation of rMSCs after osteoblastic induction. METHODS: MTT-assay and Confocal Laser Scanning Microscopy are utilized to detect rMSCs' proliferation rate and morphologic variety. RESULTS: It was found that Ti particles loading suppressed the proliferation of osteogenesis behavior of rMSCs, but the down-regulation effect varied in different circle diameter, different concentration and different loading duration of Ti particles. Especially, among three different particles, the submicron Ti particles (0.9 micron) had the most suppressive effect on rMSCs. Under the same diameter condition, the inhibitory effect induced by Ti particles loading showed a manner dependent on the particles concentration and exposure duration. The reductive response from 1 g/L Ti was the earliest and most intense one to come forth. And the lower the concentration was in use, the weaker would be the reductive response. Furthermore, with the elongation of exposure to Ti particles, proliferation was steadily decreasing and its lowest level was at 32 h of exposure. CONCLUSION: These findings demonstrated that Ti particles loading could suppress the viability of rMSCs' osteoblastic differentiation in a manner dependent on the circle diameter, particles concentration, and treatment time.

Animals↗

PubMed2004

[The effect of mechanical stimulation on the proliferation and synthetic function of osteoblasts from osteoporotic rat].

The purpose of this paper is to investigate that the effect of cyclic biaxial mechanical strain on proliferation and synthetic function in the osteoblasts isolated from 3 month-old normal female Sprague-Dawley (SD) rats and osteoporotic rats. The osteoblasts were cultured in F-12 medium contained with 10% fetal bovine serum (FBC) and grown to subconfluency in Flexercell apparatus in a humidified incubator with 5% CO2 and 95% air at 37 degrees C. Mechanical strain was applied to the cells for periods of 30 min, 2, 4 and 8 hours every day,lasting 2 days. The amplitude of mechanical strain applied to the cells were 400, 1000 and 4000 microm strain respectively, at a frequency of one hertz (1 H). Unstrained cells were used as control. The results showed that proliferation activity of osteoblast in osteoporotic rats are higher than that in normal rats without mechanical strain the mechanical strain can elevate the proliferation activity and the synthetic function of osteoblast from normal rats at 400, 1000 microm strain. However, the mechanical strain increased significantly the proliferation in the osteoblasts and suppressed obviously the synthetic function in the osteoblasts at 4000 microm strain. The mechanical strain don't affect the proliferation activity and the synthetic function of osteoblast from osteoporotic rats at 400 microm strain. The mechanical strain decrease the proliferation activity of osteoblast from osteoporotic rats at 1000 microm strain. The mechanical strain can elevate the proliferation activity and the synthetic function of osteoblast from osteoporotic rats at 4000 microm strain. In our study, the reaction of the osteoblasts from normal rats and osteoporotic rats to the mechanical stimulation suggested that there are more highly sensitive to the mechanical stimulation in the osteoblasts from normal rats than that from osteoporotic rats.

Animals↗

PubMed2004

Effect of steady and oscillatory shear stress on F-actin content and distribution in neutrophils.

We investigated neutrophil activation, specifically F-actin content and distribution, in situations mimicking the in vivo environment using steady and oscillatory shear. Under low steady shear (<150 s(-1)) F-actin levels were decreased for both treated (n-formyl-L-methioryl-L-leucyl-L-phenylalanine (fMLP)) and untreated neutrophils. The F-actin content increased with a change to higher steady shear levels. Neutrophils show the same behavior of decreased F-actin content for oscillatory shear (26.7 s(-1)) as they did for steady shear. In both situations, the low shear levels caused a decrease in F-actin content. However, as the magnitude of the shear rate increased, cells showed a reversal to increasing F-actin content. Shear caused a decrease in F-actin in the cell cortex for both control and fMLP treated cells. Ctyochalasin B (CB), a common F-actin assembly blocker, significantly decreased F-actin content. The results indicate that neutrophils regulate their actin network based on the level and type of shear stress they encounter in the bloodstream.

Actins↗