Platelet deficiency in <Emphasis Type="Italic">Tpo</Emphasis><Superscript>−/−</Superscript> mice can both promote and suppress the metastasis of experimental breast tumors in an organ-specific manner

Platelets are thought to play an important role in metastasis formation, although the mechanisms involved remain incompletely understood. Here we studied the influence of platelet numbers on organ-specific metastasis to the lungs and lymph nodes using Tpo deficient mice that have low platelet counts. After tail vein injection of 4T1 breast cancer cells, the number of lung metastases was significantly lower in Tpo^?/? mice compared to Tpo^+/+ mice. The same was true for the bone-tropic 4T1.2 derivative. In spontaneous orthotopic metastasis assays, 4T1 and 4T1.2 primary tumor growth was not affected by the genotype of the mice. However, the number of 4T1.2 lung metastases was significantly lower in Tpo^?/? mice compared to Tpo^+/+ mice, whereas the number of 4T1 lung metastases was unaffected. Moreover, in mice bearing 4T1 tumors, lymph node metastases were larger in the Tpo^?/? background, and lymph node metastasis frequency was higher in Tpo^?/? mice bearing 4T1.2 tumors compared to that in wild-type mice. Enhanced lymph node metastasis in Tpo^?/? mice was not associated with changes in peritumoral lymphatic vessel density in the primary tumors. Together, our data indicate that platelets do not affect primary tumor growth in this breast cancer model, but can differentially influence site-specific metastasis to lymph nodes and lungs.     

γδT cells but not αβT cells contribute to sepsis-induced white matter injury and motor abnormalities in mice

Background

Infection and sepsis are associated with brain white matter injury in preterm infants and the subsequent development of cerebral palsy.

Methods

In the present study, we used a neonatal mouse sepsis-induced white matter injury model to determine the contribution of different T cell subsets (αβT cells and γδT cells) to white matter injury and consequent behavioral changes. C57BL/6J wild-type (WT), T cell receptor (TCR) δ-deficient (Tcrd ^?/?, lacking γδT cells), and TCRα-deficient (Tcra ^?/?, lacking αβT cells) mice were administered with lipopolysaccharide (LPS) at postnatal day (PND) 2. Brain myelination was examined at PNDs 12, 26, and 60. Motor function and anxiety-like behavior were evaluated at PND 26 or 30 using DigiGait analysis and an elevated plus maze.

Results

White matter development was normal in Tcrd ^?/? and Tcrα ^?/? compared to WT mice. LPS exposure induced reductions in white matter tissue volume in WT and Tcrα ^?/? mice, but not in the Tcrd ^?/? mice, compared with the saline-treated groups. Neither LPS administration nor the T cell deficiency affected anxiety behavior in these mice as determined with the elevated plus maze. DigiGait analysis revealed motor function deficiency after LPS-induced sepsis in both WT and Tcrα ^?/? mice, but no such effect was observed in Tcrd ^?/? mice.

Conclusions

Our results suggest that γδT cells but not αβT cells contribute to sepsis-induced white matter injury and subsequent motor function abnormalities in early life. Modulating the activity of γδT cells in the early stages of preterm white matter injury might represent a novel therapeutic strategy for the treatment of perinatal brain injury.

     

The TRPM4 channel is functionally important for the beneficial cardiac remodeling induced by endurance training

Cardiac hypertrophy (CH) is an adaptive process that exists in two distinct forms and allows the heart to adequately respond to an organism’s needs. The first form of CH is physiological, adaptive and reversible. The second is pathological, irreversible and associated with fibrosis and cardiomyocyte death. CH involves multiple molecular mechanisms that are still not completely defined but it is now accepted that physiological CH is associated more with the PI3-K/Akt pathway while the main signaling cascade activated in pathological CH involves the Calcineurin-NFAT pathway. It was recently demonstrated that the TRPM4 channel may act as a negative regulator of pathological CH by regulating calcium entry and thus the Cn-NFAT pathway. In this study, we examined if the TRPM4 channel is involved in the physiological CH process. We evaluated the effects of 4 weeks endurance training on the hearts of Trpm4 ^+/+ and Trpm4 ^?/? mice. We identified an elevated functional expression of the TRPM4 channel in cardiomyocytes after endurance training suggesting a potential role for the channel in physiological CH. We then observed that Trpm4 ^+/+ mice displayed left ventricular hypertrophy after endurance training associated with enhanced cardiac function. By contrast, Trpm4 ^?/? mice did not develop these adaptions. While Trpm4 ^?/? mice did not develop gross cardiac hypertrophy, the cardiomyocyte surface area was larger and associated with an increase of Tunel positive cells. Endurance training in Trpm4 ^+/+ mice did not increase DNA fragmentation in the heart. Endurance training in Trpm4 ^+/+ mice was associated with activation of the classical physiological CH Akt pathway while Trpm4 ^?/? favored the Calcineurin pathway. Calcium studies demonstrated that TRPM4 channel negatively regulates calcium entry providing support for activation of the Cn-NFAT pathway in Trpm4 ^?/? mice. In conclusion, we provide evidence for the functional expression of TRPM4 channel in response to endurance training. This expression may help to maintain the balance between physiological and pathological hypertrophy.     

Dietary phosphate supplement does not rescue skeletal phenotype in a mouse model for craniometaphyseal dysplasia

Background

Mutations in the human progressive ankylosis gene (ANKH; Mus musculus ortholog Ank) have been identified as cause for craniometaphyseal dysplasia (CMD), characterized by progressive thickening of craniofacial bones and flared metaphyses of long bones. We previously reported a knock-in (KI) mouse model (Ank ^KI/KI) for CMD and showed transiently lower serum phosphate (Pi) as well as significantly higher mRNA levels of fibroblast growth factor 23 (Fgf23) in Ank ^KI/KI mice. FGF23 is secreted by bone and acts in kidney to promote Pi wasting which leads to lower serum Pi levels. Here, we examined whether increasing the Pi level can partially rescue the CMD-like skeletal phenotype by feeding Ank ^+/+ and Ank ^KI/KI mice with high Pi (1.7 %) diet from birth for 6 weeks. We studied the Pi metabolism in Ank ^KI/KI mice and CMD patients by examining the Pi regulators FGF23 and parathyroid hormone (PTH).

Results

High Pi diet did not correct CMD-like features, including massive jawbone, increased endosteal and periosteal perimeters and extensive trabeculation of femurs in Ank ^KI/KI mice shown by computed microtomography (μCT). This unexpected negative result is, however, consistent with normal serum/plasma levels of the intact/active form of FGF23 and PTH in Ank ^KI/KI mice and in CMD patients. In addition, FGF23 protein expression was unexpectedly normal in Ank ^KI/KI femoral cortical bone as shown by immunohistochemistry despite increased mRNA levels for Fgf23. Renal expression of genes involved in the FGF23 bone-kidney axis, including mFgfr1, mKlotho, mNpt2a, mCyp24a1 and m1αOHase, were comparable between Ank ^+/+ and Ank ^KI/KI mice as shown by quantitative real-time PCR. Different from normal FGF23 and PTH, serum 25-hydroxyvitamin D was significantly lower in Ank ^KI/KI mice and vitamin D insufficiency was found in four out of seven CMD patients.

Conclusions

Our data suggests that FGF23 signaling and Pi metabolism are not significantly affected in CMD and transiently low Pi level is not a major contributor to CMD.

     

Brain inflammation is accompanied by peripheral inflammation in <Emphasis Type="Italic">Cstb</Emphasis><Superscript><Emphasis Type="Italic">−/−</Emphasis></Superscript> mice,a model for progressive myoclonus epilepsy

Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1) is an autosomal recessively inherited childhood-onset neurodegenerative disorder, characterized by myoclonus, seizures, and ataxia. Mutations in the cystatin B gene (CSTB) underlie EPM1. The CSTB-deficient (Cstb ^?/? ) mouse model recapitulates key features of EPM1, including myoclonic seizures. The mice show early microglial activation that precedes seizure onset and neuronal loss and leads to neuroinflammation. We here characterized the inflammatory phenotype of Cstb ^?/? mice in more detail. We found higher concentrations of chemokines and pro-inflammatory cytokines in the serum of Cstb ^?/? mice and higher CXCL13 expression in activated microglia in Cstb ^?/? compared to control mouse brains. The elevated chemokine levels were not accompanied by blood-brain barrier disruption, despite increased brain vascularization. Macrophages in the spleen and brain of Cstb ^?/? mice were predominantly pro-inflammatory. Taken together, these data show that CXCL13 expression is a hallmark of microglial activation in Cstb ^?/? mice and that the brain inflammation is linked to peripheral inflammatory changes, which might contribute to the disease pathology of EPM1.     

Tanshinone IIA Attenuates Atherosclerosis in Apolipoprotein E Knockout Mice Infected with <Emphasis Type="Italic">Porphyromonas gingivalis</Emphasis>

Tanshinone IIA (TSA), a pharmacologically active component isolated from Danshen, may prevent cardiovascular diseases due to its anti-inflammatory, anti-oxidative, and anti-adipogenic effects. Porphyromonas gingivalis, a major periodontal pathogen, may contribute to the progression of atherosclerosis. Here, we studied the effects of TSA on atherosclerosis in ApoE^?/? mice with P. gingivalis infection. Eight-week-old ApoE^?/? mice were randomized to (a) phosphate-buffered saline (PBS), (b) P. gingivalis, and (c) P. gingivalis + TSA (60 mg kg^?1 day^?1). The mice were injected with (a) PBS, or (b) and (c) P. gingivalis 3 times per week for a total of 10 times. After 8 weeks, atherosclerotic risk factors in serum and in heart, aorta, and liver tissues were analyzed in all mice using Oil Red O, atherosclerosis cytokine antibody arrays, enzyme-linked immunosorbent assay (ELISA), real-time PCR, and microRNA array. CD40, G-CSF, IFN-γ, interleukin (IL)-1β, IL-6, MCP-1, MIP-3α, tumor necrosis factor-α (TNF-α), and VEGF were attenuated by TSA in atherosclerosis cytokine antibody arrays. TSA-treated mice showed a significant reduction of C-reactive protein (CRP), ox-LDL, IL-1β, IL-6, IL-12, and TNF-α in ELISA data. Real-time PCR analyses showed that TSA decreased the expression of CCL-2, CD40, IL-1β, IL-6, TNF-α, and MMP-2 in heart and aorta tissues. Moreover, hepatic CRP was downregulated by TSA, although FASN and HMG-CoA were not. The relative expressions of miR-146b and miR-155 were elevated by P. gingivalis infection and were downregulated by TSA treatment. These results suggest that TSA was a potential therapeutic agent that may have the ability to prevent P. gingivalis-induced atherosclerosis associated with anti-inflammatory and anti-oxidative effects.     

G<Subscript>i2</Subscript>α protein deficiency: A model for inflammatory bowel disease

Mice deficient for the G protein subunit G_i2α were obtained by gene targeting. They displayed a growth retardation that was apparent at 6 weeks of age. They subsequently developed diffuse colitis with clinical and histopathological features closely resembling those of ulcerative colitis in humans. Seven of 20 G_i2α-deficient mice with colitis also developed adenocarcinomas of the colon. G_i2α-deficient thymocytes displayed two-to fourfold increases in mature CD4⁺8^? and CD4^?8⁺ phenotypes, an approximately threefold increase in highintensity CD3 staining and enhanced proliferative responses to T-cell receptor stimuli. Stimulation of G_i2α-deficient peripheral T cells induced a hyperresponsive profile of interleukin-2, tumor necrosis factor, and interferon-γ production, which may reflect a heightened response of primed cells or a defective negative regulation. We suggest that G_i2α-deficient mice may represent a useful animal model for dissecting the pathomechanisms of inflammatory bowel disease and also for the development of novel therapeutic strategies.     

The host control of a clinical isolate strain of <Emphasis Type="Italic">P. aeruginosa</Emphasis> infection is independent of Nod-1 but depends on MyD88

Objective and design

The objective of this study was to investigate the role of Nod1 in the recruitment of neutrophils into the infection site and in the establishment of the inflammatory response elicited by a clinical isolate strain of P. aeruginosa in vivo, while comparing it to the well-established role of MyD88 in this process.

Subjects

Wild-type, Nod1^?/? and MyD88^?/? mice, all with a C57Bl/6 background.

Methods

Mice were intranasally infected with Pseudomonas aeruginosa DZ605. Bronchoalveolar lavage and blood were harvested 6 or 20 h post-infection for evaluating bacterial load, chemokine levels and neutrophil migration. Survival post-infection was also observed.

Results

We show here that wild-type and Nod1^?/? mice induce similar lung chemokine levels, neutrophil recruitment, and bacterial load, thus leading to equal survival rates upon P. aeruginosa pulmonary infection. Furthermore, we confirmed the essential role of MyD88-dependent signalling in recruiting neutrophils and controlling P. aeruginosa-induced pulmonary infection.

Conclusion

The results suggest that in contrast to MyD88, under our experimental conditions, the absence of Nod1 does not impair the recruitment of neutrophils in response to P. aeruginosa DZ605.

     

Matrix metalloproteinase-14 triggers an anti-inflammatory proteolytic cascade in endotoxemia

?

Matrix metalloproteinases can modulate the inflammatory response through processing of cyto- and chemokines. Among them, MMP-14 is a non-dispensable collagenase responsible for the activation of other enzymes, triggering a proteolytic cascade. To identify the role of MMP-14 during the pro-inflammatory response, wildtype and Mmp14 ^?/? mice were challenged with lipopolysaccharide. MMP-14 levels decreased after endotoxemia. Mutant animals showed 100% mortality, compared to 50% in wildtype mice. The increased mortality was related to a more severe lung injury, an impaired lung MMP-2 activation, and increased levels of the alarmin S100A9. There were no differences in the expression of other mediators including Il6, Cxcl2, Tgfb, Il10, or S100a8. A similar result was observed in lung explants of both genotypes cultured in presence of lipopolysaccharide. In this ex vivo model, exogenous activated MMP-2 ameliorated the observed increase in alarmins. Samples from septic patients showed a decrease in serum MMP-14 and activated MMP-2 compared to non-septic critically ill patients. These results demonstrate that the MMP-14-MMP-2 axis is downregulated during sepsis, leading to a proinflammatory response involving S100A9 and a more severe lung injury. This anti-inflammatory role of MMP-14 could have a therapeutic value in sepsis.

Key messages

? MMP-14 levels decrease in lungs from endotoxemic mice and serum from septic patients.? Mmp14 ^?/? mice show increased lung injury and mortality following endotoxemia.? Absence of Mmp14 decreases activated MMP-2 and increases S100A9 levels in lung tissue.? MMP-14 ameliorates inflammation by promoting S100A9 cleavage by activated MMP-2.

     

Cathepsin H deficiency in mice induces excess Th1 cell activation and early-onset of EAE though impairment of toll-like receptor 3 cascade

Objective

The objective of this study is to investigate the role of cathepsin H (CatH), a lysosomal cysteine protease, in the development of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis.

Methods

EAE was induced in CatH-deficient mice (CatH^?/?) and wild-type littermates (+/+) using myelin oligodendrocyte glycoprotein (MOG) 35–55. The effects of CatH deficiency were determined by clinical scoring, mRNA expression levels of Tbx21, Rorc and FoxP3, protein levels of poly(I:C)-induced toll-like receptor 3 (TLR3) and phosphorylation of IRF3, and secretion of interferon-β (IFN-β) by splenocytes.

Results and conclusions

CatH^?/? showed a significantly earlier disease onset of EAE and increased Th1 cell differentiation in splenocytes. Splenocytes prepared from immunized CatH^?/? showed a significant decrease in poly(I:C)-induced increased TLR3 expression, interferon regulatory factor 3 (IRF3) phospholylation and IFN-β secretion. Therefore, CatH deficiency impaired TLR3-mediated activation of IRF3 and consequent secretion of IFN-β from dendritic cells, leading to the enhancement of Th1 cell differentiation and consequent early disease onset of EAE.

     

<Emphasis Type="Italic">Tlr2</Emphasis> deficiency does not limit the development of left ventricular hypertrophy in a model of transverse aortic constriction induced pressure overload

Background

Toll-like receptors (TLRs) are involved in a variety of cardiovascular disorders, including septic cardiomyopathy, ischemia/reperfusion, heart failure, and cardiac hypertrophy. Previous research revealed that TLR4 promotes cardiac hypertrophy in vivo. Therefore, we investigated whether TLR2 is also involved in the development of cardiac hypertrophy.

Methods

Tlr2 deficient and wild type mice were subjected to transverse aortic constriction (TAC) or sham operation procedure. Left ventricular, heart and lung weights as well as hemodynamic parameters were determined after 3, 14 or 28 days. Real-time RT PCR was used to evaluate left ventricular gene expression. Protein content was determined via ELISA.

Results

TAC increased systolic left ventricular pressure, contraction and relaxations velocities as well as the heart weight in both genotypes. Tlr2 deficiency significantly enhanced cardiac hypertrophy after 14 and 28 days of TAC. Left ventricular end-diastolic pressure and heart rate increased in Tlr2 ^?/? TAC mice only. Fourteen days of TAC led to a significant elevation of ANP, BNP, TGFβ and TLR4 mRNA levels in Tlr2 ^?/? left ventricular tissue.

Conclusion

These data suggest that Tlr2 deficiency may promote the development of cardiac hypertrophy and ventricular remodeling after transverse aortic constriction.

     

<Emphasis Type="Italic">Slc11a1</Emphasis> (<Emphasis Type="Italic">Nramp</Emphasis>-<Emphasis Type="Italic">1</Emphasis>) gene modulates immune-inflammation genes in macrophages during pristane-induced arthritis in mice

Objective and design

Pristane-induced arthritis (PIA) in AIRmax mice homozygous for Slc11a1 R and S alleles was used to characterize the influence of Slc11a1 gene polymorphism on immune responses during disease manifestation. Previous reports demonstrated that the presence of the Slc11a1 S allele increased the incidence and severity of PIA in AIRmax ^SS , suggesting that this gene could interact with inflammatory loci to modulate PIA. We investigated the effects of Slc11a1 alleles on the activation of phagocytes during PIA.

Treatment

Mice were injected intraperitoneally with two doses of 0.5 mL of mineral oil pristane at 60-day intervals. Arthritis development was accompanied for 180 days.

Results

AIRmax ^SS mice showed differential peritoneal macrophage gene expression profiles during PIA, with higher expression and production of H₂O₂, NO, IL-1β, IL-6, TNF-α, and several chemokines. The presence of the Slc11a1 R allele, on the other hand, diminished the intensity of macrophage activation, restricting arthritis development.

Conclusion

Our data demonstrated the fine-tuning roles of Slc11a1 alleles modulating macrophage activation, and consequent PIA susceptibility, in those mouse lines.

     

Pluripotent Conversion of Muscle Stem Cells Without Reprogramming Factors or Small Molecules

Muscle derived stem cells (MDSCs) are multipotent stem cells that can differentiate into several lineages including skeletal muscle precursor cells. Here, we show that MDSCs from myostatin null mice (Mstn ^?/? ) can be readily induced into pluripotent stem cells without using reprogramming factors. Microarray studies revealed a strong upregulation of markers like Leukemia Inhibitory factor (LIF) and Leukemia Inhibitory factor receptor (LIFR) in Mstn ^?/? MDSCs as compared to wild type MDSCs (WT-MDSCs). Furthermore when cultured in mouse embryonic stem cell media with LIF for 95 days, Mstn ^?/? MDSCs formed embryonic stem cell (ES) like colonies. We termed such ES like cells as the culture-induced pluripotent stem cells (CiPSC). CiPSCs from Mstn ^?/? MDSCs were phenotypically similar to ESCs, expressed high levels of Oct4, Nanog, Sox2 and SSEA-1, maintained a normal karyotype. Furthermore, CiPSCs formed embryoid bodies and teratomas when injected into immunocompromised mice. In addition, CiPSCs differentiated into somatic cells of all three lineages. We further show that culturing in ES cell media, resulted in hypermethylation and downregulation of BMP2 in Mstn^?/? MDSCs. Western blot further confirmed a down regulation of BMP2 signaling in Mstn ^?/? MDSCs in supportive of pluripotent reprogramming. Given that down regulation of BMP2 has been shown to induce pluripotency in cells, we propose that lack of myostatin epigenetically reprograms the MDSCs to become pluripotent stem cells. Thus, here we report the successful establishment of ES-like cells from adult stem cells of the non-germline origin under culture-induced conditions without introducing reprogramming genes.     

Chemokine CXCL13 activates p38 MAPK in the trigeminal ganglion after infraorbital nerve injury

Recent data demonstrated that chemokine CXCL13 mediates neuroinflammation and contributes to the maintenance of neuropathic pain after nerve injury in the spinal cord. Pro-nociceptive chemokines activate mitogen-activated protein kinases (MAPKs) which are potential signaling pathways contributing to the nociceptive behavior in inflammatory or neuropathic pain. However, whether activation of p38 and JNK MAPK signaling pathway in the trigeminal ganglion (TG) are involved in CXCL13 and its receptor CXCR5-mediated orofacial pain has not yet been clarified. Here, we show that the unilateral partial infraorbital nerve ligation (pIONL) induced a profound orofacial pain in wild-type (WT) mice. Western blot results showed that pIONL induced p38 but not JNK activation in the TG of WT mice. However, the orofacial pain induced by pIONL was alleviated in Cxcr5 ^?/? mice, and the activation of p38 was also abrogated in Cxcr5 ^?/? mice. Furthermore, intra-TG injection of CXCL13 evoked mechanical hypersensitivity and increased p-p38 expression in WT mice. But CXCL13 had no effect on pain behavior or p-p38 expression in Cxcr5 ^?/? mice. Finally, pretreatment with p38 inhibitor, SB203580, attenuated the pIONL-induced mechanical allodynia and decreased the mRNA expression of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the TG. Taken together, our data suggest that CXCL13 acts on CXCR5 to increase p38 activation and further contributes to the pathogenesis of orofacial neuropathic pain.     

Functional Evaluation of an <Emphasis Type="Italic">IKBKG</Emphasis> Variant Suspected to Cause Immunodeficiency Without Ectodermal Dysplasia

Hypomorphic IKBKG mutations in males are typically associated with anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID). Some mutations cause immunodeficiency without EDA (NEMO-ID). The immunological profile associated with these NEMO-ID variants is not fully documented. We present a 2-year-old patient with suspected immunodeficiency in which a hemizygous p.Glu57Lys IKBKG variant was identified. At the age of 1 year, he had an episode of otitis media that evolved into a bilateral mastoiditis (Pseudomonas spp). Hypogammaglobulinemia, specific (polysaccharide) antibody deficiency, and low switched memory B cell subsets were noticed. The mother was heterozygous for the variant but had no signs of incontinentia pigmenti. Patient peripheral blood mononuclear cells produced low amounts of IL-6 after stimulation with IL-1β, Pam₃CSK_4, and FSL-1. In patient fibroblasts, IκB-α was degraded normally upon stimulation with IL-1β or TNF-α. Transduction of wild-type and variant NEMO in NEMO^?/? deficient SV40 fibroblasts revealed a slight but significant reduction of IL-6 production upon stimulation with IL-1β and TNF-α. In conclusion, we demonstrated that p.Glu57Lys leads to specific immunological defects in vitro. No other pathogenic PID variants were identified through whole exome sequencing. As rare polymorphisms have been described in IKBKG and polygenic inheritance remains an option in the presented case, this study emphasizes the need for thorough functional and genetic evaluation when encountering and interpreting suspected disease-causing NEMO-ID variants.     

miR-451 limits CD4<Superscript>+</Superscript> T cell proliferative responses to infection in mice

MicroRNAs (miRNAs) are major regulators of cell responses, particularly in stressed cell states and host immune responses. Some miRNAs have a role in pathogen defense, including regulation of immune responses to Plasmodium parasite infection. Using a nonlethal mouse model of blood stage malaria infection, we have found that miR-451^?/? mice infected with Plasmodium yoelii XNL cleared infection at a faster rate than did wild-type (WT) mice. MiR-451^?/? mice had an increased leukocyte response to infection, with the protective phenotype primarily driven by CD4⁺ T cells. WT and miR-451^?/? CD4⁺ T cells had similar activation responses, but miR-451^?/? CD4⁺ cells had significantly increased proliferation, both in vitro and in vivo. Myc is a miR-451 target with a central role in cell cycle progression and cell proliferation. CD4⁺ T cells from miR-451^?/? mice had increased postactivation Myc expression. RNA-Seq analysis of CD4⁺ cells demonstrated over 5000 differentially expressed genes in miR-451^?/? mice postinfection, many of which are directly or indirectly Myc regulated. This study demonstrates that miR-451 regulates T cell proliferative responses in part via a Myc-dependent mechanism.     

EEG indices correlate with sustained attention performance in patients affected by diffuse axonal injury

The aim of this study is to assess the ability of EEG-based indices in providing relevant information about cognitive engagement level during the execution of a clinical sustained attention (SA) test in healthy volunteers and DAI (diffused axonal injury)-affected patients. We computed three continuous power-based engagement indices (P _β /P _α , 1/P _α , and P _β / (P _α + P _θ )) from EEG recordings in a control group (n = 7) and seven DAI-affected patients executing a 10-min Conners’ “not-X” continuous performance test (CPT). A correlation analysis was performed in order to investigate the existence of relations between the EEG metrics and behavioral parameters in both the populations. P _β /P _α and 1/P _α indices were found to be correlated with reaction times in both groups while P _β / (P _α + P _θ ) and P _β /P _α also correlated with the errors rate for DAI patients. In line with previous studies, time course fluctuations revealed a first strong decrease of attention after 2 min from the beginning of the test and a final fading at the end. Our results provide evidence that EEG-derived indices extraction and evaluation during SA tasks are helpful in the assessment of attention level in healthy subjects and DAI patients, offering motivations for including EEG monitoring in cognitive rehabilitation practice.

Open image in new window

Graphical abstract Three EEG-derived indices were computed from four electrodes montages in a population of seven healthy volunteers and a group of seven DAI-affected patients. Results show a significant correlation between the time course of the indices and behavioral parameters, thus demonstrating their usefulness in monitoring mental engagement level during a sustained attention task.

     

Distinct Early Inflammatory Events during Ear Tissue Regeneration in Mice Selected for High Inflammation Bearing S<Emphasis Type="Italic">lc11a1 R</Emphasis> and <Emphasis Type="Italic">S</Emphasis> Alleles

High inflammatory AIRmax mice homozygous for Slc11a1 R and S alleles were produced. AIRmax ^SS mice showed faster ear tissue regeneration than AIRmax ^RR mice, suggesting that the S allele favored tissue restoration. Here, we investigated the gene expression profiles and the inflammatory reactions of AIRmax ^RR and AIRmax ^SS mice during the initial phase of ear tissue regeneration. We observed superior levels of analysis of wound myeloperoxidase and edema in AIRmax ^SS mice, although similar cell influx was verified in both lines. Of the genes, 794 were up- and 674 down-regulated in AIRmax ^RR , while 735 genes were found to be up- and 1616 down-regulated in AIRmax ^SS mice 48 h after punch. Both mouse lines showed significant over-represented genes related to cell proliferation; however AIRmax ^SS displayed up-regulation of inflammatory response genes. Quantitative PCR experiments showed higher expressions of Tgfb1, Dap12 and Trem1 genes in AIRmax ^SS mice. These results indicate that Slc11a1 gene modulated the early inflammatory events of ear tissue regeneration.     

Characterisation of VIM-2-producing <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> isolates from lower tract respiratory infections in a Spanish hospital

To analyse the antimicrobial phenotype, carbapenem mechanisms, integrons, virulence factors and molecular typing of 164 Pseudomonas aeruginosa isolates recovered from lower tract respiratory samples in a Spanish hospital (1 year) as well as the patients’ clinical data. Susceptibility testing to 12 antipseudomonal agents was determined by microdilution and metallo-beta-lactamase (MBL) phenotype by double disc method. The oprD gene was studied by PCR, sequencing and comparison with P. aeruginosa PAO1 sequence. Detection and characterisation of MBLs, class 1, 2 and 3 integrons, and virulence genes were studied by PCR and sequencing. The prevalence of carbapenem-resistant P. aeruginosa (CRPA) was 26.8%. MBL phenotype was detected in 52.3% CRPA, and all of them were disseminated throughout the intensive care unit. Most of the MBL-carrying patients presented respiratory disease, mechanical ventilation, tracheostomy, bacteraemia, ≥?30 hospitalisation days and previous treatment with carbapenems and/or ≥?3 different antimicrobial families. The bla_VIM-2 gene was the unique MBL encoding gene and was detected inside class 1 integrons. The class 1 integrons detected in 39 strains (23.8%) were associated with aminoglycosides (aadB, aadA1, aadA6, aacA4, aac(3)-I) and carbapenems resistance genes (bla_VIM-2). The aac(3)-I?+?aadA1 and bla_VIM-2 arrangements were the most prevalent ones. Thirty-one different PFGE patterns and 4 STs (ST175, ST235, ST253, ST973) were detected among the 39 intI1-positive isolates, being ST235 the most frequent. CRPA showed a great variety of alterations in oprD gene. The exoU⁺/exoS^? genotype was detected in 82.6% of bla_VIM-2-producing strains (ST235) and the exoU^?/exoS⁺ in the remaining 17.4% (ST973).     

The interplay between arms-only propelling efficiency,power output and speed in master swimmers

Purpose

To explore the interplay between arms-only propelling efficiency (η _p), mechanical power output (\(\dot W_{\text{tot}}\)) and swimming speed (V); these three parameters are indeed related through the following equation V ³ = 1/kη _p \(\dot W_{\text{tot}}\) (where k is the speed-specific drag; k = F/V ²); thus, the larger are η _p and \(\dot W_{\text{tot}}\) the larger is V. We furthermore wanted to test the hypothesis that a multiple linear regression between \(\dot W_{\text{tot}}\), η _p and V would have a stronger correlation coefficient than a linear regression between \(\dot W_{\text{tot}}\) and V alone.

Methods

To this aim we recruited 29 master swimmers (21 M/8F) who were asked to perform (1) an incremental protocol at the arm-ergometer (dry-land test) to determine \(\dot W_{\text{tot}}\) at \(\dot V\)O_2max (e.g. \(\dot V\) _max); (2) a maximal 200 m swim trial (with a pull buoy: arms only) during which V and η _p were determined.

Results

No relationship was found between \(\dot W_{\text{max}}\) and η _p (not necessarily the swimmers with the largest \(\dot W_{\text{max}}\) are those with the largest η _p and vice versa) whereas significant correlations were found between \(\dot W_{\text{max}}\) and V (R = 0.419, P = 0.024) and η _p and V (R = 0.741, P = 0.001); a multiple linear regression indicates that about 75 % of the variability of V can be explained by the variability of \(\dot W_{\text{max}}\) and η _p (R = 0.865, P < 0.001).

Conclusions

These findings indicate that η _p should be taken into consideration when the relationship between \(\dot W_{\text{max}}\) and V is investigated and that this allows to better explain the inter-subject variability in performance (swimming speed).