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Huntingtin regulates Ca(2+) chemotaxis and K(+)-facilitated cAMP chemotaxis, in conjunction with the monovalent cation/H(+) exchanger Nhe1, in a model developmental system: insights into its possible role in Huntington׳s disease.

Huntington׳s disease is a neurodegenerative disorder, attributable to an expanded trinucleotide repeat in the coding region of the human HTT … ulticellular morphogenesis. The D. discoideum htt(-)-mutant failed to undergo both K(+)-facilitated chemotaxis in spatial gradients of the major chemoattractant cAMP, and chemotaxis up a spatial gradient of Ca(2+), but behaved normally in Ca(2+)-facilitated cAMP chemotaxis and Ca(2+)-dependent flow-directed motility. This was the same phenotypic profile of t …

The effect of pamidronate delivery in bisphosphonate-naïve patients on neutrophil chemotaxis and oxidative burst.

The pathogenesis of medication-related osteonecrosis of the jaw (MRONJ), a morbid condition associated with bisphosphonate administration, has not been fully elucidated. Recent research utilizing a murine model has revealed that the neutrophil becomes dysfunctional following exposure to bisphosphonates. Accordingly, the impairment of neutrophil function could play an important role in the pathogenesis of MRONJ via an infectious mechanism mediated by the suppression of the innate immune system. Currently, the existing human data are insufficient to substantiate this theory. To investigate, we i

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… Chemotaxis The migration of PMNs toward an fMLP stimulus was deficient in patients treated with PA. Reduction in chemotactic function was observed for both salivary and blood PMNs (Fig. 2 a). Overall, there was a 61.4% and 49.1% reduction in blood and oral PMN chemotaxis, respectively ( p ≤ 0.05). … Interestingly, the previously noted effects on murine PMN chemotaxis were found to persist at four weeks following n-BP exposure which is consistent with our current results 18 . …

Quantitative proteomic analysis reveals that chemotaxis is involved in chlortetracycline resistance of Aeromonas hydrophila.

UNLABELLED: In recent years, Aeromonas hydrophila, which has been classified as a food borne pathogen, has presented with increased levels o … gulated were identified in chlortetracycline resistance strain. Bioinformatics analysis showed that chemotaxis related proteins, such as CheA-2, CheR-3, CheW-2, EnvZ, PolA, FliS and FliG were down-regulated in addition to previously reported tricarboxylic acid cycle (TCA) related proteins also being down-regulated. A subset of identified differentially expre …

Hypothetical Protein BB0569 Is Essential for Chemotaxis of the Lyme Disease Spirochete Borrelia burgdorferi.

UNLABELLED: The Lyme disease spirochete Borrelia burgdorferi has five putative methyl-accepting chemotaxis proteins (MCPs). In this report, we provide evidence that a hypothetical protein, BB0569, is essential for the chemotaxis of B. burgdorferi. While BB0569 lacks significant homology to the canonical MCPs, it contains a conserved domain (spanning residues 110 to 170) that is often evident in membrane-bound MCPs such as Tar and Tsr of Escherichia coli. Unlike Tar and Tsr, BB0569 lacks transmembrane regions and recognizable HAMP and methylation domains and is similar to TlpC, a cytoplasmic ch…

Impaired neutrophil and monocyte chemotaxis in chronic and aggressive periodontitis and effects of periodontal therapy.

BACKGROUND AND OBJECTIVES: Depressed chemotactic activity of polymorphoneutrophil (PMN) and monocyte (MN) appears to be one of the significant risk factors in the development of periodontal disease. Although bacteria are the primary etiologic factor in periodontal disease, the patient's host response is a determinant of disease susceptibility. Depressed chemotaxis of PMN and MN could lead to periodontal destruction by altering the host response i.e. impairment of the normal host response in neutralizing infection and alterations that result in destruction of the surrounding periodontal tissues…

CXCR4/SDF-1α-mediated chemotaxis in an in vivo model of metastatic esophageal carcinoma.

BACKGROUND/AIM: The chemokine receptor CXCR4 and its ligand (stromal cell-derived factor-1alpha; SDF-1α) play an important role in tumor cell chemotaxis and metastatic homing of esophageal carcinoma. Several methods are available to examine tumor cell migration in vitro. However, in vivo chemotaxis is subject to complex tumor-host interactions. The aim of this study was to establish an in vivo model of chemotaxis for esophageal carcinoma that allows the examination of tumor cell migration and metastatic homing in the complex microenvironment. MATERIALS AND METHODS: CXCR4 expression of OE19 ad…

Chemokine-enhanced chemotaxis of lymphangioleiomyomatosis cells with mutations in the tumor suppressor TSC2 gene.

Lymphangioleiomyomatosis (LAM) is characterized by cystic lung destruction caused by LAM cells (smooth-muscle-like cells) that have mutations in the tumor suppressor genes tuberous sclerosis complex (TSC) 1 or 2 and have the capacity to metastasize. Since chemokines and their receptors function in chemotaxis of metastatic cells, we hypothesized that LAM cells may be recruited by chemokine(s) in the lung. Quantification of 25 chemokines in bronchoalveolar lavage fluid from LAM patients and healthy volunteers revealed that concentrations of CCL2, CXCL1, and CXCL5 were significantly higher in sam…

Role of RacC for the regulation of WASP and phosphatidylinositol 3-kinase during chemotaxis of Dictyostelium.

WASP family proteins are key players for connecting multiple signaling pathways to F-actin polymerization. To dissect the highly integrated … ants and racC null cells move at a significantly slower speed and show a poor directionality during chemotaxis. Our results suggest that RacC plays an important role in PI 3-kinase activation and WASP activation for dynamic regulation of F-actin assembly during Dictyostelium chemotaxis.

A Dictyostelium homologue of WASP is required for polarized F-actin assembly during chemotaxis.

The actin cytoskeleton controls the overall structure of cells and is highly polarized in chemotaxing cells, with F-actin assembled predomin … defects in polarized F-actin assembly, resulting in an inability to establish axial polarity during chemotaxis. GFP-WASP preferentially localizes at the leading edge and uropod of chemotaxing cells and the B domain of WASP is required for the localization of WASP. We demonstrated that the B domain binds to PI(4,5)P2 and PI(3,4,5)P3 with similar affinities. T …

Inhibition of oxidative burst and chemotaxis in human phagocytes by Legionella pneumophila zinc metalloprotease.

Legionella pneumophila produces several extracellular proteins, but their role in the pathogenesis of Legionnaires' disease is unclear. This study examined the effects of the L. pneumophila major secretory protein (Msp), a zinc metalloprotease, on the oxidative burst and chemotaxis of human phagocytes. Polymorphonuclear leucocytes (PMNLs) and adherent monocytes treated with sublethal amounts of Msp protease were stimulated with formyl-leucyl-methionyl-phenylalanine (fMLP) and opsonised zymosan particles (ZAP). A dose-dependent inhibition in superoxide anion production in response to both stimu…

Severity of localized juvenile periodontitis as related to polymorphonuclear chemotaxis and specific microbial isolates.

The purpose of this study was twofold: (a) to determine if an association exists between severity of localized juvenile periodontitis (LJP) and impairment of polymorphonuclear leukocyte (PMN) chemotaxis and/or colonization by specific microbial isolates; (b) to determine if the number of specific microbial isolates, i.e., Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Eikenella corrodens, and Campylobacter rectus correlates to clinical severity of sites with LJP. Thirty-six first molars in nine subjects with LJP were examined. A …

[Chemotaxis activity of neutrophils and monocytes in patients with psoriasis vulgaris in relation to PUVA therapy].

With regard to the existing possibility favored by many immunologists that study on neutrophil (N) and monocyte (Mo) may throw light on the pathogenetic mechanism of clinical conditions such as psoriasis, the effect of PUVA therapy on human N and Mo chemotaxis in psoriasis vulgaris (PV) was investigated. One hundred psoriatic patients with severe clinical picture participated in this study: 20 with acute exanthematic form, 16 with chronic stable form and 64 patients in acute flare of the chronic course. Eitzman's modified method introduced originally by Rebuck was employed prior to and after P…

Accumulation and chemotaxis of natural killer/large granular lymphocytes at sites of virus replication.

A model for monitoring the accumulation of natural killer cell/large granular lymphocytes (NK/LGL) at a site of virus replication was studie … n a unidirectional manner across two 5-microns pore size polycarbonate filters during 7 hr in vitro chemotaxis assays. Wash-out fluid obtained from the peritoneal cavity contained chemotactic activity for NK/LGL as well as for other cell types. We conclude that production and/or release of chemotactic factors at sites of virus replication are at least partia …

Abnormal monocyte chemotaxis in patients with breast cancer: evidence for a tumor-mediated effect.

The chemotactic responsiveness of peripheral blood monocytes was measured in 194 individuals: 37 patients with breast cancer, 17 patients with a history of breast cancer but clinically free of disease after surgery, 42 patients with benign breast masses, and 98 normal controls. Monocyte chemotactic responsiveness (MCR) in vitro was not significantly different from normal [mean = 72.8 migrating monocytes/oil immersion field, +/- 9.3 (1 SD)] in 2 groups of patients: a) those with benign breast masses (mean = 72.6 +/- 15.1; P greater than 0.3) and b) those previously having breast cancer resected

Chemotaxis and movement of Physarum polycephalum and its responses to some neurotransmitters and psychomimetic compounds.

A method was developed for studying the effect of some neurotransmitters and drugs on the rate of movement and the chemotactic value of the plasmodium of Physarum polycephalum. Epinephrine (adrenaline) at a concentration of 1 mg/ml, reduced the rate of movement and shortened the length of the cycles of shuttle streaming, but did not affect the chemotactic response. The drugs DL-amphetamine, cannabinol and heroin diminished the rate of movement, whereas Na-barbitol misled the chemotactic response.

Macrophage BMPRIB mediates p38-dependent inflammatory reprogramming and chemotaxis during ventilator-induced lung injury.

BACKGROUND: Ventilator-induced lung injury (VILI) is a major iatrogenic complication of mechanical ventilation, in which dysregulated inflammation, particularly macrophage-driven response, amplifies pulmonary damage. Although bone morphogenetic protein (BMP) signaling exhibits context-dependent effects in pulmonary disorders, whether specific BMP receptors (BMPRs) regulate macrophage function during VILI remains unknown. METHODS: Mice subjected to mechanical ventilation were randomly divided into Control (intubation without ventilation), LVT (low tidal volume), and HVT (high tidal volume) gro

Immobilization-free chemotaxis analysis reveals the novel behavioral mode of "leaving" in Caenorhabditis elegans.

Animals balance staying in a favorable environment with exploring new ones. In C. elegans chemotaxis, the process by which worms migrate toward an attractant has been extensively studied. However, what happens after they reach it remains largely unexplored, partly because conventional assays immobilize worms at the point of arrival. Here, we quantitatively analyzed chemotactic behavior upon reaching an attractive odor source using an immobilization-free chemotaxis assay. We observed that 62% animals left the isoamyl alcohol region after initially approaching it, a behavior we termed "leaving b…

Enhanced bacterial chemotaxis in confined microchannels occurs at lane widths matching circular swimming radius.

Understanding bacterial behavior in confined environments is helpful for elucidating microbial ecology and developing strategies to manage bacterial infections. While extensive research has focused on bacterial motility on surfaces and in porous media, chemotaxis in confined spaces remains poorly understood. Here, we investigate the chemotaxis of Escherichia coli within microfluidic lanes under a linear concentration gradient of L-aspartate. We demonstrate that E. coli exhibits significantly enhanced chemotaxis in lanes with sidewalls compared to open surfaces. We attribute this phenomenon pri…

CCR1hi/CCL5hi macrophage-mediated CCL5hi T cell chemotaxis in salivary gland aggravates Sjögren's syndrome.

INTRODUCTION: CCR1 upregulation in macrophages promotes sequential T/B-cell infiltration via CCL5-mediated crosstalk, aggravating salivary gland damage in Sjögren's syndrome (SS), implicating CCR1/CCL5 as potential therapeutic targets. OBJECTIVES: To investigate the role of CCR1/CCL5 in salivary gland lymphocytic infiltration and SS progression. METHODS: Functional enrichment analysis was performed on four bulk RNA-seq datasets to identify common immune pathways, highlighting CCR1 as a key factor. Cytohubba and STRING analyses identified CCL5 as the primary ligand for CCR1 in SS salivary gla