Cell Migration In Mice Research Articles

Lithium enhances post-stroke blood-brain barrier integrity, activates the MAPK/ERK1/2 pathway and alters immune cell migration in mice

Lithium induces neuroprotection against cerebral ischemia, although the underlying mechanisms remain elusive. We have previously suggested a role for lithium in calcium regulation and (extra)cerebral vessel relaxation under non-ischemic conditions. Herein, we aimed to investigate whether or not lithium contributes to post-stroke stabilization of the blood-brain barrier (BBB) in mice. Using an oxygen-glucose-deprivation (OGD) model, we first analyzed the impact of lithium treatment on endothelial cells (EC) in vitro. Indeed, such treatment of EC exposed to OGD resulted in increased cell survival as well as in enhanced expression of tight junction proteins and P-glycoprotein. Additional in vivo studies demonstrated an increased stabilization of the BBB upon lithium treatment in stroke mice, as shown by a reduced Evans blue extravasation and an elevation of tight junction protein expression. Furthermore, stabilization of the BBB as a consequence of lithium treatment was associated with an inhibition of matrix metalloproteinase-9 activity, independent of calveolin-1 regulation. In line with this, flow cytometry analysis revealed that lithium treatment led to a decreased neutrophil invasion and an increased T cell extravasation from the blood compartment towards the brain parenchyma. We finally identified the pro-survival MAPK/ERK1/2 pathway as the key regulator of the impact of lithium on the BBB. In conclusion, we demonstrate for the first time that lithium is able to enhance post-stroke BBB integrity. Importantly, our work delivers novel insights into the exact mechanism of lithium-induced acute neuroprotection, providing critical information for future clinical trials involving lithium treatment in stroke patients.

(Invited) Water-Soluble Near-Infrared Fluorophores Emitting over 1000 Nm and Their Application to In Vivo Imaging in the Second Optical Window

Near-infrared (NIR) emitting fluorophores are widely used as bio-imaging probes for non-invasive visualization of deep-tissues at the whole body level, because of the high permeability and low absorption of NIR light in living tissues. Recently much attention has been paid for NIR fluorescence imaging at the wavelengths of 1000-1400 nm (second optical window) to obtain clearer deep-tissue images with high signal to background ratios. This is because that the NIR light with longer wavelengths (1000-1400 nm) is highly permeable with lower scattering compared with the conventional NIR light (700-1000 nm). In the second optical window, there are a very limited number of fluorophores that can be used for NIR fluorescence imaging. To date, single walled carbon nanotubes (SWNTs), PbS quantum dots (QDs) and Ag2S QDs, rare-earth metal doped nanoparticles (NPs) have been reported as NIR fluorophores for in vivo imaging in the second optical window. In this work, we synthesized several types of water-soluble NIR fluorophores, glutathione coated PbS QDs, glutathione coated Ag2S QDs, Er3+-doped NaYF4 nanoparticles (Er3+-NPs) and cholate-capped SWNTs that emit over 1000 nm. For the application of the NIR fluorophores to in vivo imaging, we examined their fluorescence brightness, particle size, and cytotoxicity. We found that among the NIR fluorophores, PbS QDs are the brightest fluorophore (quantum yield, 4 %) with no significant cytotoxicity. The fluorescence of Ag2S QDs, Er3+-NPs, and SWNTs was at least 50 times week compared with that of PbS QDs. We show the capability of the NIR fluorophores for in vivo imaging of cerebral blood vessels, tumor angiogenesis, lymph nodes, and phagocytic cell migration in mice.

Abstract 4163: Space radiation-induced persistent DNA damage and alterations in cytoskeletal remodeling pathways affect intestinal epithelial cell migration in mice

Abstract Lombardi Comprehensive Cancer Center, and Department of Biochemistry and Molecular & Cellular Biology Georgetown University, Washington, DC 20057, USA. Heavy ion space radiation is considered as a risk factor of gastrointestinal (GI) cancer and perturbed intestinal epithelial cell (IEC) migration has been implicated in GI carcinogenesis. The purpose of the current study was to assess rate of IEC migration as well as dissect key IEC migration signaling events after exposure to heavy ion 56Fe irradiation and compare the results to sham- and γ-irradiation. Male C57BL/6J mice were exposed to 0.5 Gy of either γ or 56Fe radiation and control mice were sham irradiated. IEC migration distance was measured 7 and 60 d after exposure using BrdU pulse labeling. We also analyzed cell polarity, microtubule dynamics, and adhesion dynamics using immunoblots and immunofluorescence. Measure of IEC migration rate showed a greater decrease after 56Fe relative to γ radiation at both the time points. At the molecular level, compared to sham and γ radiation, 56Fe radiation exhibited significantly greater impairment of cell adhesion dynamics evidenced by altered integrins and Rock1 as well as cytoskeletal dynamics evidenced by altered MLCK expression. Similarly, perturbed cell polarity, tight junction, and microtubule dynamics was revealed by the deregulation of Par3, Claudin1, Scribble, Occludin, ZO-1, phospho-Tau and MAP1B. Also, the Wnt/β-catenin and EphB/EphrinB pathways critical for IEC migration consistently showed greater deregulation at both the time points tested after 56Fe radiation relative to γ -rays. Taken together, our molecular findings correlate with the BrdU pulse labeling data, and demonstrate greater effects of heavy ion 56Fe on IEC migration relative to γ -rays. In summary, our results have demonstrated for the first time that radiation can disrupt cell migration dynamics through alteration of signaling molecules involved in crucial cellular processes and these results have implications for heavy ion space radiation-induced gastrointestinal homeostatic deregulation and carcinogenesis. Citation Format: Santosh Kumar, Shubhankar Suman, Albert Fornace, Kamal Datta. Space radiation-induced persistent DNA damage and alterations in cytoskeletal remodeling pathways affect intestinal epithelial cell migration in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4163.

Critical Review—Water-Soluble Near-Infrared Fluorophores Emitting over 1000 nm and Their Application to In Vivo Imaging in the Second Optical Window (1000–1400 nm)

Near-infrared (NIR) emitting fluorophores are widely used as bio-imaging probes for non-invasive visualization of deep-tissues at the whole body level, because of the high permeability and low absorption of NIR light in living tissues. Recently much attention has been paid for NIR fluorescence imaging at the wavelengths of 1000–1400 nm (second optical window) to obtain clearer deep-tissue images with high signal to background ratios. This is because that the NIR light with longer wavelengths (1000–1400 nm) is highly permeable with lower scattering compared with the conventional NIR light (700–1000 nm). In the second optical window, there are a very limited number of fluorophores that can be used for NIR fluorescence imaging. To date, single walled carbon nanotubes (SWNTs), PbS quantum dots (QDs) and Ag2S QDs, rare-earth metal doped nanoparticles (NPs) have been reported as NIR fluorophores for in vivo imaging in the second optical window. In this work, we synthesized several types of water-soluble NIR fluorophores, glutathione coated PbS QDs, glutathione coated Ag2S QDs Er3+-doped NaYF4 nanoparticles (Er3+-NPs) and cholate-capped SWNTs that emit over 1000 nm. For the application of the NIR fluorophores to in vivo imaging, we examined their fluorescence brightness, particle size, and cytotoxicity. We found that among the NIR fluorophores, PbS QDs are the brightest fluorophore (quantum yield, 4%) with no significant cytotoxicity. The fluorescence of Ag2S QDs, Er3+-NPs, and SWNTs was at least 50 times week compared with that of PbS QDs. We show the capability of the NIR fluorophores for in vivo imaging of cerebral blood vessels, tumor angiogenesis, lymph nodes, and phagocytic cell migration in mice.

Icariin-treated human umbilical cord mesenchymal stem cells decrease chronic liver injury in mice.

Human umbilical cord mesenchymal stem cells (hUMSCs) have been shown to have multiple differentiation potentials. However, a key problem is that only a small number of hUMSCs can migrate to damaged tissue after transplantation. According to "The Theory of Kidney Essence" in Traditional Chinese Medicine, some traditional Chinese medicines used for tonifying the kidneys can be applied in promoting the differentiation and migration of stem cells in vivo. Our previous study demonstrated that icariin (ICA) could up-regulate the pluripotent genes of hUMSCs in vitro and induce cell migration in mice in an acute kidney injury model in vivo. The aim of this study was to investigate the effects of ICA-induced hUMSCs in chronic liver injury (CLI) caused by carbon tetrachloride (CCl4). CLI was induced by intraperitoneal injection of CCl4. ICA-treated hUMSCs were transplanted via intra-venous injection. The animals were followed for survival, biochemistry analysis and pathology. The results show that ICA-treated hUMSCs accelerate the recovery of liver function in mice with CLI. In addition, ICA-treated hUMSCs increase the anti-oxidant activities in liver and prevent the progression to hepatic fibrosis. Moreover, ICA induces the migration of hUMSCs to the injured liver tissue. In conclusion, these data demonstrate that ICA-treated hUMSCs exhibit recovery and protective properties in the mice model of CCl4-induced CLI.

P110γ and p110δ isoforms of phosphoinositide 3-kinase differentially regulate natural killer cell migration in health and disease

The mechanisms that regulate NK cell trafficking are unclear. Phosphoinositide-3 kinases (PI3K) control cell motility and the p110gamma and p110delta isoforms are mostly expressed in leukocytes, where they transduce signals downstream of G protein coupled receptors (GPCR) or tyrosine kinase receptors, respectively. Here, we set out to determine the relative contribution of p110gamma and p110delta to NK cell migration in mice. Using a combination of single-cell imaging analysis of transgenic cells reporting on PI3K activity in real time and small molecule inhibitors of p110gamma and p110delta, we show here that the tyrosine-kinase coupled p110delta is linked to GPCR signaling and, depending on the GPCR, may even be preferentially activated over p110gamma. Using gene-targeted mice, we showed that both isoforms were essential for NK cell chemotaxis to CXCL12 and to CCL3 and, in vivo, for normal NK cell migration during pregnancy and to the inflamed peritoneum. By contrast, only p110delta was indispensable for chemotaxis to S1P and CXCL10 and for NK cell distribution throughout lymphoid and nonlymphoid tissues and for extravasation to tumors. These results implicate p110delta downstream of GPCRs in NK cells and highlight its nonredundant role as a key regulator of NK cell trafficking in health and disease.

Stromal cell derived factor-1 enhances bone marrow mononuclear cell migration in mice with acute liver failure

To evaluate the number of bone marrow mononuclear cells (BMMC) that are migrated to the liver following transplantation of murine BMMC into mice with acute liver injury. BMMC were isolated from the bone marrow of mice in a lymphocyte separation medium and then labeled with PKH26. The labeled cells were subsequently infused into the caudal veins of BALB/c mice with hepatic injury induced by carbon tetrachloride and 2-acetylaminofluorene. Mice in experimental group were treated with stromal cell-derived factor-1 (SDF-1) which was injected intraperitoneally after transplantation of BMMC. Mice in control group were injected intraperitoneally with 0.1 mL of saline (0.9% NaCl) after transplantation of BMMC. After 2 wk, migration of the cells in experimental group was studied by fluorescence microscopy. The expression of proliferating cell nuclear antigen and albumin was quantified with manual methods in both groups. The serum transaminase levels at different time points were compared between the two groups. The labeled "cells" were found in the portal region and central veins of hepatic lobules. The PKH26-labeled cells appeared at an average frequency of 108 +/- 8/high power field in the experiment group and 65 +/- 8/high power field in the control group (P < 0.05). The total number of positive cells was 29 +/- 7/high power field in the experimental group and 13 +/- 2/high power field in the control group. The albumin expression level was also higher in the experimental group than in the control group (29 +/- 7 vs 13 +/- 2, P < 0.05). The total number of crossing points was 156 +/- 5/high power field in the experimental group and 53 +/- 5/high power field in the control group (P < 0.05). The serum alanine aminotransferase levels in experimental and control groups were measured at different time points (120 +/- 40 vs 118.50 +/- 1.75, P > 0.05; 80.60 +/- 6.50 vs 101.08 +/- 5.67, P < 0.05; 50.74 +/- 5.38 vs 80.47 +/- 4.62, P < 0.05; 30.54 +/- 2.70 vs 60.72 +/- 4.37, P < 0.05; 30.77 +/- 5.36 vs 40.47 +/- 6.50, P < 0.05). At the same time, the serum aspartate aminotransferase levels were measured in experimental and control groups at different time points (122.55 +/- 1.46 vs 120.70 +/- 4.22, P > 0.05; 54.26 +/- 6.50 vs 98.70 +/- 8.20, P < 0.05; 39.47 +/- 5.39 vs 78.34 +/- 4.50, P < 0.05; 28.94 +/- 2.70 vs 56.44 +/- 4.28, P < 0.05; 30.77 +/- 5.45 vs 42.50 +/- 6.28, P < 0.05). SDF-1 can promote the migration of BMMC to the liver of mice with acute liver failure.

Inhibition of HMG CoA reductase reveals an unexpected role for cholesterol during PGC migration in the mouse.

BackgroundPrimordial germ cells (PGCs) are the embryonic precursors of the sperm and eggs. Environmental or genetic defects that alter PGC development can impair fertility or cause formation of germ cell tumors.ResultsWe demonstrate a novel role for cholesterol during germ cell migration in mice. Cholesterol was measured in living tissue dissected from mouse embryos and was found to accumulate within the developing gonads as germ cells migrate to colonize these structures. Cholesterol synthesis was blocked in culture by inhibiting the activity of HMG CoA reductase (HMGCR) resulting in germ cell survival and migration defects. These defects were rescued by co-addition of isoprenoids and cholesterol, but neither compound alone was sufficient. In contrast, loss of the last or penultimate enzyme in cholesterol biosynthesis did not alter PGC numbers or position in vivo. However embryos that lack these enzymes do not exhibit cholesterol defects at the stage at which PGCs are migrating. This demonstrates that during gestation, the cholesterol required for PGC migration can be supplied maternally.ConclusionIn the mouse, cholesterol is required for PGC survival and motility. It may act cell-autonomously by regulating clustering of growth factor receptors within PGCs or non cell-autonomously by controlling release of growth factors required for PGC guidance and survival.

Low-Level Laser Therapy (GaAsλ= 904 nm) Reduces Inflammatory Cell Migration in Mice with Lipopolysaccharide-Induced Peritonitis

This study was designed to study the effect of an infrared low-level laser (GaAs lambda = 904 nm, 4 mW) on inflammatory cell migration in lipopolysaccharide (LPS)-induced peritonitis in mice. It has been suggested that red wavelengths of low-level laser therapy (LLLT) can exert anti-inflammatory effects, but little is known about the anti-inflammatory effects of infrared lasers. Peritonitis is a potentially life-threatening inflammatory condition that may be suitable for studying anti-inflammatory effects of infrared lasers. Sixty male mice were randomly divided into five groups, and one group was given an intraperitoneal sterile saline injection. In the remaining four groups, peritonitis was induced by an intraperitoneal LPS injection. Animals in three of the LPS groups were irradiated at a single point over the peritoneum with doses of 3 J/cm(2), 7.5 J/cm(2), and 15 J/cm(2), respectively. The fourth group injected with LPS was an LPS-control group. At 6 hours after injection the groups irradiated with doses of 3 J/cm(2) and 7.5 J/cm(2) had a reduced number of neutrophil cells in the peritoneal cavity compared with the LPS-control group, and there were significant differences between the number of neutrophils in the peritoneal cavity between the LPS-control group and groups irradiated with doses of 3 J/cm(2) (-42%) and 7.5 J/cm(2) (-70%). In the group irradiated with 15 J/cm(2), neutrophil cell counts were lower than, but not significantly different from, LPS controls (-38%; p = 0.07). At 24 hours after injection, both neutrophil and total leukocyte cell counts were lower in all the irradiated groups than in the LPS controls. The 3-J/cm(2) exposure group showed the best results at 24 hours, with reductions of 77% in neutrophil and 49% in leukocyte counts. Low-level laser therapy (904 nm) can reduce inflammatory cell migration in mice with LPS-induced peritonitis in a dose-dependent manner.

Dysregulation of intestinal crypt cell proliferation and villus cell migration in mice lacking Krüppel-like factor 9

Krüppel-like factor 9 (Klf9), a zinc-finger transcription factor, is implicated in the control of cell proliferation, cell differentiation, and cell fate. Using Klf9-null mutant mice, we have investigated the involvement of Klf9 in intestine crypt-villus cell renewal and lineage determination. We report the predominant expression of Klf9 gene in small and large intestine smooth muscle (muscularis externa). Jejunums null for Klf9 have shorter villi, reduced crypt stem/transit cell proliferation, and altered lineage determination as indicated by decreased and increased numbers of goblet and Paneth cells, respectively. A stimulatory role for Klf9 in villus cell migration was demonstrated by bromodeoxyuridine labeling. Results suggest that Klf9 controls the elaboration, from intestine smooth muscle, of molecular mediator(s) of crypt cell proliferation and lineage determination and of villus cell migration.

Differential effects of UVA1 and UVB radiation on Langerhans cell migration in mice

The UVB (280–315 nm)- and UVA1 (340–400 nm)-induced migration of Langerhans cells (LC) from the epidermis and accumulation of dendritic cells (DC) in the lymph nodes draining the exposed skin site of C3H/HeN mice have been investigated. One minimum erythemal dose (MED) of UVB (1.5 kJ/m 2) and of UVA1 (500 kJ/m 2) were chosen, which have been shown previously to suppress delayed hypersensitivity (DTH). UVB irradiation resulted in a reduction in epidermal LC numbers, local to the site of the exposure, which was most apparent 12 h after exposure, but, in contrast, UVA1 had no significant effect even at 72 h after exposure. UVA1 did not exert any protection against the UVB-mediated depletion in LC numbers. The reduction in local LC following UVB exposure was prevented by systemic (intraperitoneal) treatment of mice with neutralising antibodies to either tumor necrosis factor (TNF)-α or interleukin (IL)-β 2 h prior to the irradiation. It has been reported previously that UVB exposure caused an increase in the number of dendritic cells (DC) in the lymph nodes draining the irradiated skin site. In the present study we have shown that UVA1 had a similar effect. Pretreatment of the mice with neutralising antibodies to IL-1β (by intraperitoneal injection) substantially inhibited DC accumulation induced by both UV regimens. However, anti-TNF-α antibodies affected only the UVB-induced increase, and did not alter the elevation in DC numbers observed following UVA1 exposure. These results indicate that UVB causes the migration of LC from the epidermis and an accumulation of DC in the draining lymph nodes by a mechanism that requires both TNF-α and IL-1β. In contrast, UVA1 does not cause LC migration from the epidermis and the accumulation of DC in the draining lymph nodes observed following UVA1 exposure requires IL-1β, but not TNF-α. It is likely therefore that UVA1 acts through a different mechanism from UVB and may target a cutaneous antigen presenting cell other than LC, such as the dermal DC.

Langerhans cell migration in mice requires intact type I interleukin 1 receptor (IL-1RI) function.

Langerhans cell migration in mice requires intact type I interleukin 1 receptor (IL-1RI) function.

Stimulation of Langerhans cell migration in mice by tumour necrosis factor alpha and interleukin 1 beta.

Following contact sensitization or other forms of cutaneous trauma epidermal Langerhans cells (LC) are stimulated to migrate from the skin and to travel, via afferent lymphatics, to draining lymph nodes.1 We have demonstrated previously that tumour necrosis factor α (TNF-α), a keratinocyte-derived epidermal cytokine, provides one stimulus for LC migration.2 It has been shown that intradermal injection of mice with homologous recombinant TNF-α induces a rapid reduction in the frequency of epidermal LC local to the site of exposure and results, somewhat later, in the accumulation of dendritic cells (DC) in draining lymph nodes.3,4 Systemic (intraperitoneal) treatment of mice with a neutralizing anti-TNF-α antibody prior to topical sensitization with oxazolone, a potent contact allergen, was found to inhibit almost completely the accumulation of DC in draining nodes normally provoked by exposure to this chemical. Such treatment was found also to suppress the development of contact sensitization.5 In the present investigations we have examined whether another epidermal cytokine interleukin 1β (IL-1β), a product of LC, also plays a role in LC migration. Attention has focused on IL-lβ for three reasons. First, it has been shown that the development of contact hypersensitivity is compromised in 1L-1s gene deletion transgenics,6 or in mice that have been treated with an anti-IL-1β antibody.7 Second, there is evidence suggesting that IL-1β, a cytokine which is upregulated very rapidly following contact sensitization8, is able to provoke the increased expression of TNF-α by keratinocytes.7 Third, it has been claimed on the basis of experiments performed with human skin explants that IL-1β may affect LC migration in vitro.9 We here describe investigations in which the influence of IL-1β and TNF-α on LC migration and DC accumulation were examined.

Kinetics of hematopoietic stem cell migration in mice after severe mechanical trauma

Experiments on mice have shown that severe mechanical trauma brings about phasic changes in the kinetics of hemopoietic stem cell migration. Within the first four days after the trauma the migration of stem cells gets intensified and returns to normal by day 8. This reaction is regarded to be a defence one, since it guarantees the function of the most important component of immunity, namely the organs where stem cells differentiate as T and B lymphocytes.