Flagella are important protein structures on the cell surface of bacteria and the main appendage for bacterial swimming. Flagella play a crucial role in bacterial motility, chemotaxis, pathogenicity, and environmental sensing. With the development of microscopic tracking technology and flagellum visualization tools, new forms of flagellar motility and increasing roles of flagella in the physiological activities of bacteria have been discovered. This review introduces the visualization methods of flagella and the applications of these methods in studying flagellar functions, giving insights into exploring the functions of flagella and laying a theoretical foundation for its future applications in inhibiting bacterial transmission and treating bacterial infections.
Flagella/physiology* ; Bacterial Physiological Phenomena ; Chemotaxis/physiology* ; Bacteria

Sepsis remains one of the leading causes of death globally, in spite of advanced developments in intensive care and better understandings of pathophysiology related to sepsis. There is no special treatment or drug available for sepsis, currently. Under normal circumstances, neutrophil is a major player in acute infection control. However, during sepsis, the migration abilities and antimicrobial functions of neutrophils are impaired, resulting in a dysregulated immune response. Recent studies have indeed demonstrated that blocking or reversing neutrophil migration and impaired antibacterial function can improve the outcomes in septic animal models. This article systemically synthesized information regarding related factors and signaling involved in the functions of neutrophils in sepsis. This review also discussed the possibility that neutrophils be used as a marker for specific diagnosis and/or prediction of the outcomes of sepsis.
Animals ; Neutrophils/physiology* ; Chemotaxis ; Chemotaxis, Leukocyte ; Sepsis ; Cell Movement

The ginseng endophytic bacteria F1 is a potential biocontrol agent for ginseng bacterial soft rot. In this paper,the chemotactic response of ginseng endophytic bacteria F1 on 8 kinds of sugar and amino acids was detected by capillary method to explore its biocontrol mechanism. The chemotactic response of F1 strain to 4 kinds of better chemotaxis substances such as glucose,glycine,L-rhamnoseand L-glutamic acid under parameters( concentration,time,temperature and pH) was studied. The results showed that under the same experimental conditions( incubation temperature 25 ℃,incubation time 60 min,chemotaxis concentration 1 mg·L~(-1)),ginseng endophytic bacteria F1 showed different degrees of response to the eight substances tested. The phenomenon of positive chemotaxis of the measured sugars and amino acids was obvious,and the chemotactic response to total ginsenosides was low. The degree of chemotaxis response is positively correlated with the chemotaxis index within a certain range of parameters,but as the temperature,p H,time,concentration and other factors continue to increase,the chemotaxis effect decreases,and F1 optimizes the chemotaxis of the four substances. The parameters are as follows: glucose: 25 ℃,10 mg·L~(-1),45 min,pH 7; glycine: 30 ℃,10 mg·L~(-1),75 min,pH7; L-rhamnose: 30 ℃,1 mg·L~(-1),30 min,pH 6; L-glutamic acid: 25 ℃,0. 1 mg·L~(-1),45 min,pH 8. The chemotactic response is more sensitive to low concentrations of chemotactic substances.
Amino Acids/pharmacology* ; Bacteria/drug effects* ; Chemotaxis ; Endophytes/physiology* ; Ginsenosides/pharmacology* ; Panax/chemistry* ; Plant Exudates/pharmacology* ; Sugars/pharmacology*

OBJECTIVE: To compare the differences of neutrophils chemotaxis ability in peritoneal cavity between normal rats and schizopherenic rats with cell dynamic visualization system. METHODS: In the study,18 healthy Kunming rats were randomly divided into 3 groups which were control group (n=6), 0.3 mg/kg MK-801 treatment group (n=6), 0.6 mg/kg dizocilpine maleate (MK-801) treatment group(n=6), extracted neutrophils separately, and observed the morphology and counted under a microscope. Each group of cells was divided into two parts for chemotactic experiment, called chemokine agent treatment group and no chemokine agent treatment group respectively, indicating control 1, 0.3 mg/kg MK-801 treatment 1,0.6 mg/kg MK-801 treatment 1 and control 2, 0.3 mg/kg MK-801 treatment 2,0.6 mg/kg MK-801 treatment 2. The dynamic migration of cells was recorded using the NIS-Elements software, and TAXIScan Analyzer 2 software was used to select 30 cells (n=30) in each group of cells and analyze cells migration trajectory, speed and distance, and use pair test and One-Way analysis of variance for statistical analysis. RESULTS: The number of neutrophils in control group, 0.3 mg/kg MK-801 treatment group and 0.6 mg/kg MK-801 treatment group were(1.00±0.03)×10⁴/mL,(0.05±0.02)×10⁴/mL,(0.32±0.01)×10⁴/mL respectively, the differences of results were statistically significant(P<0.05).Under the effect of chemotactic agent,the directional migration capability of neutrophils in control group 1, 0.3 mg/kg MK-801 treatment group 1 and 0.6 mg/kg MK-801 treatment group 1 were(0.85±0.11) radian,(1.00±0.11) radian,(0.96±0.10) radian respectively (P<0.05); the migration velocities of neutrophils were (0.09±0.02) μm/s,(0.12±0.01) μm/s,(0.14±0.01) μm/s respectively (P<0.05);the migration distances of neutrophils were (94.26±0.02) μm,(134.61±0.01) μm,(156.19±0.01) μm respectively(P<0.05). CONCLUSION Compared with neutrophils in peritoneal cavity of control group, the neutrophils in peritoneal cavity of schizophrenic rats have stronger chemotactic movement ability.
Animals ; Cell Movement ; Chemokines ; Chemotaxis ; Disease Models, Animal ; Dizocilpine Maleate ; Mice ; Neutrophils/physiology* ; Peritoneal Cavity ; Rats ; Schizophrenia/physiopathology*

In this paper, three kinds of chemotactic parameters (concentration, temperature and pH) were determined by plate assay and spore germination method to research the chemotactic response of Botrytis cinerea and Alternaria panax, and their spores on total ginsenosides. The results showed that Botrytis cinerea had strong chemotactic response at the mid-concentration of total ginsenosides (cultivation temperature was 20 degrees C and pH value was 6), and the data of chemotactic migration index (CMI) was 1.293 0, chemotactic growth rate (CGR) was 0.476 0, spore germination rate (SGR) was 53%, and dry weight of mycelial (DWM) was 0.452 6 g x L(-1); however, Alternaria panax had strong chemotactic response at the low-concentration of total ginsenosides (cultivation temperature was 25 degrees C and pH value was 6), and the data of chemotactic migration index (CMI) was 1.235 4, chemotactic growth rate (CGR) was 0.537 0, spore germination rate (SGR) was 67%, and dry weight of mycelial (DWM) was 0.494 8 g x L(-1). The results indicated that the low and middle concentration (2, 20 mg x L(-1)) of total ginsenosides had significant promoting effect on chemotactic response of these two pathogens, and the spore germination, mycelial growth rate, dry weight of mycelial of them were also significantly improved by this chemotactic response, whereas it decreased as the increase of total ginsenosides concentration.
Alternaria ; drug effects ; growth & development ; physiology ; Botrytis ; drug effects ; growth & development ; physiology ; Chemotaxis ; drug effects ; Drugs, Chinese Herbal ; metabolism ; pharmacology ; Ginsenosides ; metabolism ; pharmacology ; Panax ; metabolism ; microbiology ; Plant Diseases ; microbiology ; Spores, Fungal ; drug effects ; growth & development ; physiology

OBJECTIVETo investigate the expression of chemokine stromal cell-derived factor-1 (SDF-1) receptor CXCR4 in human gingival mesenchymal stem cells (GMSCs) and the migration potential of GMSCs stimulated with SDF-1.

METHODSHuman GMSCs were isolated by single-cell cloning method. Their cell surface markers were characterized by flow cytometry, and the rate of colony formation was evaluated. Differentiation assay was used to detect the differentiation potential of GMSCs. The expression of chemokine SDF-l receptor CXCR4 in GMSCs was detected by immunocytochemical staining. The chemotactic effect of SDF-1 on GMSCs was detected using a 24-multiwell Transwell cell culture chamber. The number of net migrated cells was counted in different microscope fields.

RESULTSHuman GMSCs possessed high self-renewal potential and formed single-cell colonies cultured in vitro. GMSCs expressed mesenchymal stem cells-associated markers CD44, CD73, CD90, CD105, and CD166, and the expression of hemopoietic stem cell surface markers CD14, CD34, and CD45 was negative. GMSCs differentiated into osteoblasts and adipocytes under defined culture conditions. The colony forming unit-fibroblastic for GMSCs was 21.4%/±2.8%. Immunocytochemical staining demonstrated that GMSCs expressed chemokine SDF-1 receptor CXCR4. The number of GMSCs migrating at concentrations of 100 ng.mL-1 and 200 ng.mL-1 of SDF-l in the Transwell cell culture chamber was significantly higher than that of the negative control (189.3±4.4, 164.6±4.9 cells/field vs. 47.8±2.5 cells/field, P<0.01). Treatment with the CXCR4 neutralizing antibody, an antagonist for CXCR4, significantly reduced the migratory effect compared with the negative controls (29.0±2.4 cells/field vs. 47.8±2.5 cells/field, P<0.01).

CONCLUSIONHuman GMSCs express chemokine SDF-l receptor CXCR4. SDF-1 may participate in regulating chemotaxis of human GMSCs. Results suggest that the migration induced by SDF-1 is mediated by CXCR4.

Adipocytes ; Cell Culture Techniques ; Cell Differentiation ; Chemokine CXCL12 ; metabolism ; Chemotaxis ; Flow Cytometry ; Gingiva ; physiology ; Humans ; Mesenchymal Stromal Cells ; physiology ; Osteoblasts ; Receptors, CXCR4 ; Signal Transduction

Although empirically well understood in their clinical administration, volatile anesthetics are not yet well comprehended in their mechanism studies. A major conundrum emerging from these studies is that there is no validated model to assess the presumed candidate sites of the anesthetics. We undertook this study to test the hypothesis that the single-celled Paramecium could be anesthetized and served as a model organism in the study of anesthetics. We assessed the motion of Paramecium cells with Expert Vision system and the chemoresponse of Paramecium cells with T-maze assays in the presence of four different volatile anesthetics, including isoflurane, sevoflurane, enflurane and ether. Each of those volatiles was dissolved in buffers to give drug concentrations equal to 0.8, 1.0, and 1.2 EC50, respectively, in clinical practice. We could see that after application of volatile anesthetics, the swimming of the Paramecium cells was accelerated and then suppressed, or even stopped eventually, and the index of the chemoresponse of the Paramecium cells (denoted as I ( che )) was decreased. All of the above impacts were found in a concentration-dependent fashion. The biphasic effects of the clinical concentrations of volatile anesthetics on Paramecium simulated the situation of high species in anesthesia, and the inhibition of the chemoresponse also indicated anesthetized. In conclusion, the findings in our studies suggested that the single-celled Paramecium could be anesthetized with clinical concentrations of volatile anesthetics and therefore be utilized as a model organism to study the mechanisms of volatile anesthetics.
Anesthetics, Inhalation ; administration & dosage ; Biological Assay ; methods ; Cell Movement ; drug effects ; physiology ; Chemotaxis ; drug effects ; physiology ; Dose-Response Relationship, Drug ; Drug Evaluation, Preclinical ; methods ; Paramecium tetraurelia ; drug effects ; physiology ; Volatile Organic Compounds ; administration & dosage

OBJECTIVETo investigate the role of psoriasin in mycosis fungoides.

METHODSPsoriasin protein expressions in normal skin tissues and mycosis fungoides tissues were detected by immunohistochemistry.

RESULTSPsoriasin protein was not expressed in normal skin tissues. In 21 mycosis fungoides tissue specimens, psoriasin was expressed in the stratum corneum and stratum spinosum but not in the stratum basale, with a positivity rate of 90.5% in these specimens. Psoriasin expression was significantly higher in mycosis fungoidesa tissues than in normal tissues (P<0.001).

CONCLUSIONPsoriasin may play a role in the pathogenesis of mycosis fungoides by chemotaxis of CD4+ T lymphocytes.

Adult ; Aged ; CD4-Positive T-Lymphocytes ; physiology ; Chemotaxis ; physiology ; Female ; Humans ; Male ; Middle Aged ; Mycosis Fungoides ; etiology ; metabolism ; S100 Calcium Binding Protein A7 ; S100 Proteins ; metabolism ; Skin ; metabolism ; Young Adult

Animals ; Chemotaxis ; physiology ; Dictyostelium ; genetics ; metabolism ; physiology ; Genes, Protozoan ; genetics ; physiology ; Genes, ras ; genetics ; physiology ; Phosphatidylinositol 3-Kinase ; genetics ; metabolism ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; Protozoan Proteins ; genetics ; metabolism ; Signal Transduction ; Transcription Factors ; genetics ; metabolism

Animals integrate various environmental stimuli within the nervous system to generate proper behavioral responses. However, the underlying neural circuits and molecular mechanisms are largely unknown. The insulin-like signaling pathway is known to regulate dauer formation, fat metabolism, and longevity in Caenorhabditis elegans (C. Elegans). Here, we show that this highly conserved signaling pathway also functions in the integrative response to an olfactory diacetyl and a gustatory Cu(2+) stimuli. Worms of wild-type N2 Bristol displayed a strong avoidance to the Cu(2+) barrier in the migration pathway to the attractive diacetyl. Mutants of daf-2 (insulin receptor), daf-18 (PTEN lipid phosphatase), pdk-1 (phosphoinositide-dependent kinase), akt-1/-2 (Akt/PKB kinase) and sgk-1 (serum- and glucocorticoid-inducible kinase) show severe defects in the elusion from the Cu(2+). Mutations in DAF-16, a forkhead-type transcriptional factor, suppress the integrative defects of daf-2 and akt-1/-2 mutants. We further report that neither cGMP nor TGFβ pathways, two other dauer formation regulators, likely plays a role in the integrative learning. These results suggest that the insulin-like signaling pathway constitutes an essential component for sensory integration and decision-making behavior plasticity.
Animals ; Caenorhabditis elegans ; genetics ; physiology ; Caenorhabditis elegans Proteins ; genetics ; physiology ; Chemotaxis ; genetics ; physiology ; Copper ; physiology ; Cyclic GMP ; genetics ; physiology ; Diacetyl ; metabolism ; Insulin ; metabolism ; Longevity ; Signal Transduction ; Smell ; genetics ; physiology ; Taste ; genetics ; physiology ; Transforming Growth Factor beta ; genetics ; physiology