Pre-transplant immune factors may be associated with BK polyomavirus reactivation in kidney transplant recipients

BK polyomavirus (BKPyV) reactivation in kidney transplant recipients can lead to allograft damage and loss. The elements of the adaptive immune system that are permissive of reactivation and responsible for viral control remain incompletely described. We performed a prospective study evaluating BKPyV-specific T-cell response, humoral response and overall T-cell phenotype beginning pre-transplant through one year post-transplant in 28 patients at two centers. We performed an exploratory analysis of risk factors for the development of viremia and viruria as well as compared the immune response to BKPyV in these groups and those who remained BK negative. 6 patients developed viruria and 3 developed viremia. BKPyV-specific CD8⁺ T-cells increased post-transplant in viremic and viruric but not BK negative patients. BKPyV-specific CD4⁺ T-cells increased in viremic, but not viruric or BK negative patients. Anti-BKPyV IgG antibodies increased in viruric and viremic patients but remained unchanged in BK negative patients. Viremic patients had a greater proportion of CD8⁺ effector cells pre-transplant and at 12 months post-transplant. Viremic patients had fewer CD4⁺ effector memory cells at 3 months post-transplant. Exploratory analysis demonstrated lower CD4 and higher total CD8 proportions, higher anti-BKPyV antibody titers and the cause of renal failure were associated BKPyV reactivation. In conclusion, low CD4, high CD8 and increased effector CD8 cells were found pre-transplant in patients who became viremic, a phenotype associated with immune senescence. This pre-transplant T-cell senescence phenotype could potentially be used to identify patients at increased risk of BKPyV reactivation.

Interleukin-7 treatment of PML in a patient with idiopathic lymphocytopenia

Objective:

To describe the compassionate use of interleukin-7 (IL-7) for treatment of progressive multifocal leukoencephalopathy (PML) in the setting of idiopathic CD8+ greater than CD4+ lymphocytopenia.

Methods:

A 66-year-old HIV-seronegative man presented with progressive language dysfunction. MRI showed hyperintense lesions in the left hemispheric white matter with mild contrast enhancement. A brain biopsy performed 4 months after symptom onset established the diagnosis of PML. The patient had profound lymphocytopenia with absolute lymphocyte count (ALC) at 168 cells/μL, 87 CD4+ T cells/μL, and 7 CD8+ T cells/μL. There was no evidence of hematologic malignancy or rheumatologic disease.

Results:

The patient received 3 intramuscular injections of IL-7 at a dose of 10 μg/kg per week with no adverse effects. ALC peaked at 595 cells/μL, CD4+ T cells at 301 cells/μL, and CD8+ T cells at 34 cells/μL 3 weeks after completion of treatment. His lesions on MRI stabilized and neurologic examination mildly improved. JCV-specific T-cell responses measured by intracellular cytokine staining were not altered after treatment with IL-7 but there was a marked increase in regulatory T cells.

Conclusion:

This case further supports the investigational use of IL-7 in patients who develop PML in the setting of ICL.

Classification of evidence:

This study provides Class IV evidence that for patients with ICL and PML, IL-7 improves PML-related-outcomes. The study is rated Class IV because it is a case report.

JCV GCN in a natalizumab-treated MS patient is associated with mutations of the VP1 capsid gene

OBJECTIVE

To describe the clinical, neuroimaging, immunologic, and virologic characteristics of JC virus-associated granule cell neuronopathy (JCV GCN) in a natalizumab-treated patient with multiple sclerosis (MS) who developed immune reconstitution inflammatory syndrome (IRIS) after natalizumab withdrawal.

METHODS

We obtained longitudinal clinical data as well as MRI and proton magnetic resonance spectroscopy from this patient with MS. We measured JCV-specific cellular immune response in his peripheral blood by intracellular cytokine staining and sequenced a fragment of JCV VP1 capsid gene detected in his CSF. We contrast our findings with the first recently reported case.

RESULTS

This patient presented with worsening cerebellar symptoms and progressive cerebellar atrophy without new MS lesions on MRI after 63 months of natalizumab monotherapy. JCV DNA was detected in his CSF by PCR and harbored novel GCN-type mutations in the VP1 gene. He developed IRIS upon discontinuation of natalizumab and plasma exchange, which manifested itself by a worsening of clinical symptoms and contrast enhancement in the cerebellum on MRI. Treatment with corticosteroids resulted in resolution of IRIS, as demonstrated by proton magnetic resonance spectroscopy. The patient had a strong JCV-specific T-cell response in his peripheral blood and remains alive after 15 months from onset of symptoms, although with significant disability. He did not have MS relapse on glatiramer acetate.

CONCLUSIONS

JCV GCN should be considered in patients on natalizumab presenting with progressive cerebellar symptoms and cerebellar atrophy, and is associated with mutations in the JCV VP1 gene. Natalizumab withdrawal may be complicated by JCV GCN IRIS, and require treatment with corticosteroids.

A fatal case of JC virus meningitis presenting with hydrocephalus in a human immunodeficiency virus-seronegative patient

JC virus (JCV) is the etiologic agent of progressive multifocal leukoencephalopathy, JCV granule cell neuronopathy, and JCV encephalopathy. Whether JCV can also cause meningitis has not yet been demonstrated. We report a case of aseptic meningitis resulting in symptomatic hydrocephalus in a human immunodeficiency virus-seronegative patient. Brain imaging showed enlargement of ventricles but no parenchymal lesion. She had a very high JC viral load in the cerebrospinal fluid (CSF) and developed progressive cognitive dysfunction despite ventricular drainage. She was diagnosed with pancytopenia and passed away after 5.5 months. Postmortem examination revealed productive JCV infection of leptomeningeal and choroid plexus cells, and limited parenchymal involvement. Sequencing of JCV CSF strain showed an archetype-like regulatory region. Further studies of the role of JCV in aseptic meningitis and in idiopathic hydrocephalus are warranted.

JC virus reactivation during prolonged natalizumab monotherapy for multiple sclerosis

OBJECTIVE

To determine the prevalence of JC virus (JCV) reactivation and JCV-specific cellular immune response during prolonged natalizumab treatment for multiple sclerosis (MS).

METHODS

We enrolled 43 JCV-seropositive MS patients, including 32 on natalizumab monotherapy >18 months, 6 on interferon β-1a monotherapy >36 months, and 5 untreated controls. We performed quantitative real-time polymerase chain reaction in cerebrospinal fluid (CSF), blood, and urine for JCV DNA, and we determined JCV-specific T-cell responses using enzyme-linked immunosorbent spot (ELISpot) and intracellular cytokine staining (ICS) assays, ex vivo and after in vitro stimulation with JCV peptides.

RESULTS

JCV DNA was detected in the CSF of 2 of 27 (7.4%) natalizumab-treated MS patients who had no symptoms or magnetic resonance imaging-detected lesions consistent with progressive multifocal leukoencephalopathy. JCV DNA was detected in blood of 12 of 43 (27.9%) and in urine of 11 of 43 (25.6%) subjects without a difference between natalizumab-treated patients and controls. JC viral load was higher in CD34(+) cells and in monocytes compared to other subpopulations. ICS was more sensitive than ELISpot. JCV-specific T-cell responses, mediated by both CD4(+) and CD8(+) T lymphocytes, were detected more frequently after in vitro stimulation. JCV-specific CD4(+) T cells were detected ex vivo more frequently in MS patients with JCV DNA in CD34(+) (p = 0.05) and B cells (p = 0.03).

INTERPRETATION

Asymptomatic JCV reactivation may occur in CSF of natalizumab-treated MS patients. JCV DNA load is higher in circulating CD34(+) cells and monocytes compared to other mononuclear cells, and JCV in blood might trigger a JCV-specific CD4(+) T-cell response. JCV-specific cellular immune response is highly prevalent in all JCV-seropositive MS patients, regardless of treatment.

Immune reconstitution after allogeneic hematopoietic stem cell transplantation is associated with selective control of JC virus reactivation

JC virus (JCV) causes progressive multifocal leukoencephalopathy (PML) in immunocompromised patients. The mechanism of JCV reactivation and immunity in a transplanted immune system remains unclear. We prospectively studied 30 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) and collected blood and urine samples before HSCT and 3, 6, and 12 to 18 months after HSCT. Before HSCT, JCV DNA was detected in 7 of 30 urine, 5 of 30 peripheral blood mononuclear cells (PBMC) and 6 of 30 plasma samples. Although JC viruria remained stable after HSCT with detection in 5 of 21 samples, viremia was detected in only 1 of 22 plasma and none of 22 PBMC samples 12 to 18 months after HSCT. Prevalence of anti-JCV IgG was 83% before HSCT and decreased to 72% at 12 to 18 months. Anti-JCV IgM was rarely detected. JCV-specific CD4(+) and CD8(+) T cell responses increased 12 to 18 months after HSCT. Although JC viruria correlated directly with detection of anti-JCV IgG, the cellular immune response to JCV measured by ELISpot was inversely correlated with anti-JCV IgG response. The diagnosis of acute myelogenous leukemia and age group were 2 independent patient factors associated with significantly reduced cellular immune responses to JCV. This prospective study in HSCT patients provides a model of interactions between the host immune response and viral activation in multiple compartments during the recovery of the immune system.

Leptomeningeal carcinomatosis from ethmoid sinus adenocarcinoma

INTRODUCTION

Adenocarcinoma of the ethmoid is an aggressive tumor, with potential extension to surrounding structures. Leptomeningeal extension is a rarely reported entity.

CASE REPORT

A carpenter, aged 55, developed multifocal cranial nerve-related symptoms 1 week after resection of adenocarcinoma of the ethmoid, evolving towards deteriorated general health status and death 10 weeks later. Brain MRI showed diffuse contrast enhancement of the cranial nerves, and repeated cerebrospinal fluid (CSF) examination found increased protein concentration associated with decreased glucose concentration, without malignant cells. The diagnosis of carcinomatous meningitis was based on the association of clinical, CSF and brain MRI data.

DISCUSSION/CONCLUSION

Leptomeningeal dissemination of adenocarcinoma of the ethmoid is rare; diagnosis is guided by clinical signs. MRI reveals neurological spread, but the presence of malignant cells in the CSF is sufficient for diagnosis. Due to poor prognosis, the only currently available treatments are palliative.

Polypodium leucotomos extract decreases UV-induced Cox-2 expression and inflammation, enhances DNA repair, and decreases mutagenesis in hairless mice

UV-irradiated skin and UV-induced tumors overexpress the inducible isoform of cyclooxygenase-2 (Cox-2), and Cox-2 inhibition reduces photocarcinogenesis. To evaluate photoprotective effects of Polypodium leucotomos extract (PL), hairless Xpc(+/-) mice were fed for 10 days with PL (300 mg/kg) or vehicle then UV-irradiated, once. By 24 hours, UV-induced Cox-2 levels were increased in vehicle-fed and PL-fed mice, whereas by 48 and 72 hours, Cox-2 levels were four- to fivefold lower in PL-fed mice (P < 0.05). p53 expression/activity was increased in PL-fed versus vehicle-fed then UV-irradiated mice. UV-induced inflammation was decreased in PL-fed mice, as shown by approximately 60% decrease (P < 0.001) in neutrophil infiltration at 24 hours, and macrophages by approximately 50% (<0.02) at 24 and 48 hours. By 72 hours, 54 +/- 5% cyclobutane pyrimidine dimers remained in vehicle-fed versus 31 +/- 5% in PL-fed skin (P < 0.003). The number of 8-hydroxy-2'-deoxyguanosine-positive cells were decreased before UV irradiation by approximately 36% (P < 0.01), suggesting that PL reduces constitutive oxidative DNA damage. By 6 and 24 hours, the number of 8-hydroxy-2'-deoxyguanosine-positive cells were approximately 59% (P < 0.01) and approximately 79% (P < 0.03) lower in PL-fed versus vehicle-fed mice. Finally, UV-induced mutations in PL-fed-mice were decreased by approximately 25% when assessed 2 weeks after the single UV exposure. These data demonstrate that PL extract supplementation affords the following photoprotective effects: p53 activation and reduction of acute inflammation via Cox-2 enzyme inhibition, increased cyclobutane pyrimidine dimer removal, and reduction of oxidative DNA damage.

Asymptomatic reactivation of JC virus in patients treated with natalizumab

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) occurs in a fraction of patients with multiple sclerosis who were treated with natalizumab. Most adults who are infected with the JC virus, the etiologic agent in PML, do not have symptoms. We sought to determine whether exposure to natalizumab causes subclinical reactivation and neurotropic transformation of JC virus.

METHODS

We followed 19 consecutive patients with multiple sclerosis who were treated with natalizumab over an 18-month period, performing quantitative polymerase-chain-reaction assays in blood and urine for JC virus reactivation; BK virus, a JC virus-related polyomavirus, was used as a control. We determined JC virus-specific T-cell responses by means of an enzyme-linked immunospot assay and antibody responses by means of an enzyme-linked immunosorbent assay and analyzed JC virus regulatory-region sequences.

RESULTS

After 12 months of natalizumab therapy, the prevalence of JC virus in the urine of the 19 patients increased from a baseline value of 19% to 63% (P=0.02). After 18 months of treatment, JC virus was detectable in 3 of 15 available plasma samples (20%) and in 9 of 15 available samples of peripheral-blood mononuclear cells (60%) (P=0.02). JC virus regulatory-region sequences in blood samples and in most of the urine samples were similar to those usually found in PML. Conversely, BK virus remained stable in urine and was undetectable in blood. The JC virus-specific cellular immune response dropped significantly between 6 and 12 months of treatment, and variations in the cellular immune response over time tended to be greater in patients in whom JC viremia developed. None of the patients had clinical or radiologic signs of PML.

CONCLUSIONS

Subclinical reactivation of JC virus occurs frequently in natalizumab-treated patients with multiple sclerosis. Viral shedding is associated with a transient drop in the JC virus-specific cellular immune response.

Cell-free embryonic stem cell extract-mediated derivation of multipotent stem cells from NIH3T3 fibroblasts for functional and anatomical ischemic tissue repair

The oocyte-independent source for the generation of pluripotent stem cells is among the ultimate goals in regenerative medicine. We report that on exposure to mouse embryonic stem cell (mESC) extracts, reversibly permeabilized NIH3T3 cells undergo dedifferentiation followed by stimulus-induced redifferentiation into multiple lineage cell types. Genome-wide expression profiling revealed significant differences between NIH3T3 control and ESC extract-treated NIH3T3 cells including the reactivation of ESC-specific transcripts. Epigenetically, ESC extracts induced CpG demethylation of Oct4 promoter, hyperacetylation of histones 3 and 4, and decreased lysine 9 (K-9) dimethylation of histone 3. In mouse models of surgically induced hindlimb ischemia or acute myocardial infarction transplantation of reprogrammed NIH3T3 cells significantly improved postinjury physiological functions and showed anatomic evidence of engraftment and transdifferentiation into skeletal muscle, endothelial cell, and cardiomyocytes. These data provide evidence for the generation of functional multipotent stem-like cells from terminally differentiated somatic cells without the introduction of retroviral mediated transgenes or ESC fusion.

STAT3-dependent mouse embryonic stem cell differentiation into cardiomyocytes: analysis of molecular signaling and therapeutic efficacy of cardiomyocyte precommitted mES transplantation in a mouse model of myocardial infarction

Pluripotent embryonic stem (ES) cell therapy may be an attractive source for postinfarction myocardial repair and regeneration. However, the specific stimuli and signal pathways that may control ES cell-mediated cardiomyogenesis remains to be completely defined. The aim of the present study was to investigate (1) the effect and underlying signal transduction pathways of leukemia inhibitory factor (LIF) and bone-morphogenic protein-2 (BMP-2)-induced mouse ES cell (mES-D3 line) differentiation into cardiomyocytes (CMC) and (2) the efficacy of CMC precommitted mES cells for functional and anatomical cardiac repair in surgically-induced mouse acute myocardial infarction (AMI) model. Various doses of LIF and BMP-2 and their inhibitors or blocking antibodies were tested for mES differentiation to CMC in vitro. CMC differentiation was assessed by mRNA and protein expression of CMC-specific markers, Connexin-43, CTI, CTT, Mef2c, Tbx5, Nkx2.5, GATA-4, and alphaMHC. LIF and BMP-2 synergistically induced the expression of CMC markers as early as 2 to 4 days in culture. Signaling studies identified STAT3 and MAP kinase (ERK1/2) as specific signaling components of LIF+BMP-2-mediated CMC differentiation. Inhibition of either STAT3 or MAPK activation by specific inhibitors drastically suppressed LIF+BMP-2-mediated CMC differentiation. Moreover, in mouse AMI, transplantation of lentivirus-GFP-transduced, LIF+BMP-2 precommitted mES cells, improved post-MI left ventricular functions, and enhanced capillary density. Transplanted cells engrafted in myocardium and differentiated into CMC and endothelial cells. Our data suggest that LIF and BMP-2 may synergistically enhance CMC differentiation of transplanted stem cells. Thus augmentation of LIF/BMP-2 downstream signaling components or cell type specific precommitment may facilitate the effects of ES cell-based therapies for post-MI myocardial repair and regeneration.

Enhanced voluntary alcohol consumption after estrogen supplementation negates estrogen-mediated vascular repair in ovariectomized mice

Preclinical and observational studies in ovariectomized (OVX) animals and pre- and postmenopausal women, respectively, have suggested the cardioprotective effects of estrogen replacement therapy. However, randomized clinical trials have not confirmed estrogen-mediated cardioprotection. Although uncertainties about the duration and optimal type of estrogen replacement regimen might explain the disparity, other factors that may mask the protective effects of 17beta-estradiol (E2) on cardiovascular outcome need scrutiny. Increased ethanol consumption may be one such factor. We examined the effect of E2 supplementation on ethanol consumption in OVX mice and the effect of ethanol consumption on E2-mediated vascular repair, in vivo. OVX mice implanted with E2 pellets consumed significantly more ethanol, compared with those receiving placebo pellets. E2-induced increase in ethanol consumption was not affected by the absence of either estrogen receptor-alpha or -beta. Reendothelialization after carotid artery denudation was repressed, and neovascularization in ischemic hind limbs was blunted in mice consuming ethanol, despite E2 supplementation. In vitro, ethanol dose-dependently attenuated E2-induced endothelial cell (EC) proliferation and tube formation activity and enhanced EC apoptosis, suggesting that ethanol blocks E2-induced EC survival and function. Taken together our data suggest that increased ethanol consumption after E2 supplementation blunts the beneficial effects of E2 on EC function and that novel approaches to estrogen replacement for cardioprotection may benefit from the control of alcohol consumption.

Estrogen Receptors α and β Mediate Contribution of Bone Marrow–Derived Endothelial Progenitor Cells to Functional Recovery After Myocardial Infarction

Background— Estradiol (E 2 ) modulates the kinetics of circulating endothelial progenitor cells (EPCs) and favorably affects neovascularization after ischemic injury. However, the roles of estrogen receptors α (ERα) and β (ERβ) in EPC biology are largely unknown.

Methods and Results— In response to E 2 , migration, tube formation, adhesion, and estrogen-responsive element–dependent gene transcription activities were severely impaired in EPCs obtained from ERα-knockout mice (ERαKO) and moderately impaired in ERβKO EPCs. The number of ERαΚΟ EPCs (42.4±1.5; P <0.001) and ERβKO EPCs (55.4±1.8; P =0.03) incorporated into the ischemic border zone was reduced as compared with wild-type (WT) EPCs (72.5±1.3). In bone marrow transplantation (BMT) models, the number of mobilized endogenous EPCs in E 2 -treated mice was significantly reduced in ERαKO BMT (WT mice transplanted with ERαKO bone marrow) (2.03±0.18%; P =0.004 versus WT BMT) and ERβKO BMT (2.62±0.07%; P =0.02 versus WT) compared with WT BMT (2.87±0.13%) (WT to WT BMT as control) mice. Capillary density at the border zone of ischemic myocardium also was significantly reduced in ERαKO BMT and ERβKO BMT compared with WT mice (WT BMT, 1718±75/mm 2 ; ERαKO BMT, 1107±48/mm 2 ; ERβKO BMT, 1567±50/mm 2 ). ERα mRNA was expressed more abundantly on EPCs compared with ERβ. Moreover, vascular endothelial growth factor was significantly downregulated on ERαKO EPCs compared with WT EPCs both in vitro and in vivo.

Conclusions— Both ERα and ERβ contribute to E 2 -mediated EPC activation and tissue incorporation and to preservation of cardiac function after myocardial infarction. ERα plays a more prominent role in this process. Moreover, ERα contributes to upregulation of vascular endothelial growth factor, revealing possible mechanisms of an effect of E 2 on EPC biology. Finally, these data provide additional evidence of the importance of bone marrow–derived EPC phenotype in ischemic tissue repair.

IL-10-induced TNF-alpha mRNA destabilization is mediated via IL-10 suppression of p38 MAP kinase activation and inhibition of HuR expression

Inflammation plays an essential role in vascular injury and repair. Mononuclear phagocytes are important contributors in these processes, in part, via adhesive interactions and secretion of proinflammatory cytokines. The antiinflammatory cytokine interleukin (IL)-10 suppresses such responses via deactivation of monocytes/macrophages and repression of inflammatory cytokine expression. The mechanisms of IL-10's suppressive action are, however, incompletely characterized. Here, we report that systemic IL-10 treatment after carotid artery denudation in mice blunts inflammatory cell infiltration and arterial tumor necrosis factor (TNF) expression. At the molecular level, in a human monocytic cell line, U937 IL-10 suppressed LPS-induced mRNA expression of a number of inflammatory cytokines, mainly via posttranscriptional mRNA destabilization. Detailed studies on IL-10 regulation of TNF-alpha mRNA expression identified AU-rich elements (ARE) in the 3' untranslated region as a necessary determinant of IL-10-mediated TNF-alpha mRNA destabilization. IL-10 sensitivity to TNF depends on the ability of IL-10 to inhibit the expression and mRNA-stabilizing protein HuR and via IL-10 mediated repression of p38 mitogen-activated protein (MAP) kinase activation. Because IL-10 function and signaling are important components for control of inflammatory responses, these results may provide insights necessary to develop strategies for modulating vascular repair and other accelerated arteriopathies, including transplant vasculopathy and vein graft hyperplasia.

Functional disruption of alpha4 integrin mobilizes bone marrow-derived endothelial progenitors and augments ischemic neovascularization

The cell surface receptor α4 integrin plays a critical role in the homing, engraftment, and maintenance of hematopoietic progenitor cells (HPCs) in the bone marrow (BM). Down-regulation or functional blockade of α4 integrin or its ligand vascular cell adhesion molecule-1 mobilizes long-term HPCs. We investigated the role of α4 integrin in the mobilization and homing of BM endothelial progenitor cells (EPCs). EPCs with endothelial colony-forming activity in the BM are exclusively α4 integrin–expressing cells. In vivo, a single dose of anti–α4 integrin antibody resulted in increased circulating EPC counts for 3 d. In hindlimb ischemia and myocardial infarction, systemically administered anti–α4 integrin antibody increased recruitment and incorporation of BM EPCs in newly formed vasculature and improved functional blood flow recovery and tissue preservation. Interestingly, BM EPCs that had been preblocked with anti–α4 integrin ex vivo or collected from α4 integrin–deficient mice incorporated as well as control cells into the neovasculature in ischemic sites, suggesting that α4 integrin may be dispensable or play a redundant role in EPC homing to ischemic tissue. These data indicate that functional disruption of α4 integrin may represent a potential angiogenic therapy for ischemic disease by increasing the available circulating supply of EPCs.

[Dialysis-associated spondyloarthropathy. Case report and literature review]

Hemodialysis has considerably prolonged the life of patients suffering from terminal renal failure. However, long-term hemodialysis leads to new bone complications and spinal disorders such as destructive spondyloarthropathy (DSA). At the present time DSA is reported in 8% to 18% of the dialysed patients. Diagnosis is based on severe narrowing of the intervertebral disk, erosions and geodes of the adjacent vertebral plates simulating infectious spondylitis. Lesions progressively involve posterior joints and may lead to severe destruction of the spine. The pathogenesis of this syndrome is still unknown. Several factors have been implicated, including microcrystal deposition, amyloidosis, inflammatory and foreign body reactions and suggest that the pathogenesis of erosive spondyloarthropathies of hemodialysed patients is multifactorial. Spinal instability inducing myelopathy and radiculopathy were observed in 8% of the cases. Treatment must be accorded to the natural disease course and to the quality of the bone. We report the case of a chronic dialysed patient with destructive spondyloarthropathy involving the cervical and thoracic spine. Pathogenesis, radiological datas and therapeutic approach are discussed.

Ethanol modulation of TNF-alpha biosynthesis and signaling in endothelial cells: synergistic augmentation of TNF-alpha mediated endothelial cell dysfunctions by chronic ethanol

Despite reported cardio-protective effects of low alcohol intake, chronic alcoholism remains a risk factor in the pathogenesis of coronary artery disease. Dose related bimodal effects of alcohol on cardiovascular system might reflect contrasting influences of light versus heavy alcohol consumption on the vascular endothelium. Chronic ethanol induced damage to various organs has been linked to the increased release of TNF-alpha (TNF). We have previously shown that TNF, expressed at the sites of arterial injury, suppresses re-endothelialization of denuded arteries and inhibits endothelial cell (EC) proliferation in vitro. Here we report that in vitro chronic ethanol exposure enhances agonist-induced TNF mRNA and protein expression in EC. Ethanol-mediated increment in TNF expression involves increased de novo transcription without affecting mRNA stability. DNA binding assays revealed that ethanol-induced TNF up regulation was AP1 dependent. Functionally, TNF induced EC dysfunction, including reduced proliferation, migration and cyclin A expression, were all markedly enhanced in the presence of ethanol. Additionally, expression of cyclin D1 was significantly attenuated in cells co-treated with TNF and ethanol while each treatment alone had little effect on cyclin D1 expression. Furthermore, exposure to ethanol potentiated and prolonged agonist-induced activation of JNK. Inhibition of JNK by over-expression of dominant negative JNK1 substantially reversed ethanol/TNF-mediated inhibition of cyclin A expression and EC proliferation, suggesting modulation of JNK1 signaling as the mechanism for ethanol/TNF-induced EC dysfunctions. Taken together, these data indicate that chronic ethanol consumption may negatively influence post angioplasty re-endothelialization thereby contributing to the development of restenosis.

T-oligo treatment decreases constitutive and UVB-induced COX-2 levels through p53- and NFkappaB-dependent repression of the COX-2 promoter

Chronically irradiated murine skin and UV light-induced squamous cell carcinomas overexpress the inducible isoform of cyclooxygenase (COX-2), and COX-2 inhibition reduces photocarcinogenesis in mice. We have reported previously that DNA oligonucleotides substantially homologous to the telomere 3'-overhang (T-oligos) induce DNA repair capacity and multiple other cancer prevention responses, in part through up-regulation and activation of p53. To determine whether T-oligos affect COX-2 expression, human newborn keratinocytes and fibroblasts were pretreated with T-oligos or diluent alone for 24 h, UV-irradiated, and processed for Western blotting. In both cell types, T-oligos transcriptionally down-regulated base-line and UV light-induced COX-2 expression, coincident with p53 activation. In fibroblasts with wild type versus dominant negative p53 (p53(WT) versus p53(DN)), T-oligos decreased constitutive expression of a COX-2 reporter plasmid by >50%. We then examined NFkappaB, a known positive regulator of COX-2 transcription. In p53(WT) but not in p53(DN) fibroblasts and in human keratinocytes, T-oligos decreased readout of an NFkappaB promoter-driven reporter plasmid and decreased NFkappaB binding to DNA. After T-oligo treatment and subsequent UV irradiation, binding of the transcriptional co-activator protein p300 to NFkappaB was decreased, whereas binding of p300 to p53 was increased. Human skin explants provided with T-oligos had markedly decreased COX-2 immunostaining both at base-line and post-UV light, coincident with increased p53 immunostaining. We conclude that T-oligos transcriptionally down-regulate COX-2 expression in human skin via activation and up-regulation of p53, at least in part by inhibiting NFkappaB transcriptional activation. Decreased COX-2 expression may contribute to the observed ability of T-oligos to reduce photocarcinogenesis.

The cytoskeletal protein ezrin regulates EC proliferation and angiogenesis via TNF-alpha-induced transcriptional repression of cyclin A

TNF-alpha modulates EC proliferation and thereby plays a central role in new blood vessel formation in physiologic and pathologic circumstances. TNF-alpha is known to downregulate cyclin A, a key cell cycle regulatory protein, but little else is known about how TNF-alpha modulates EC cell cycle and angiogenesis. Using primary ECs, we show that ezrin, previously considered to act primarily as a cytoskeletal protein and in cytoplasmic signaling, is a TNF-alpha-induced transcriptional repressor. TNF-alpha exposure leads to Rho kinase-mediated phosphorylation of ezrin, which translocates to the nucleus and binds to cell cycle homology region repressor elements within the cyclin A promoter. Overexpression of dominant-negative ezrin blocks TNF-alpha-induced modulation of ezrin function and rescues cyclin A expression and EC proliferation. In vivo, blockade of ezrin leads to enhanced transplanted EC proliferation and angiogenesis in a mouse hind limb ischemia model. These observations suggest that TNF-alpha regulates angiogenesis via Rho kinase induction of a transcriptional repressor function of the cytoskeletal protein ezrin and that ezrin may represent a suitable therapeutic target for processes dependent on EC proliferation.

Le neurochirurgien face aux algies périnéales

The investigation of patients suffering from perineal pain when sitting led us to perform an anatomical study of the pudendal nerve. We dissected 50 cadavers and found areas of conflict for the nerve fibers. The nerve trunk can become entrapped at the level of the ischiatic spine, in the Alcock's canal and when it crosses the falciform process. Considering the clinical and neurophysiological data, this type of chronic pain may arise from compression of the nerve between the sacro-tuberal and the sacro-spinal ligaments, and/or in the fascia of the internal obturator muscle. Much like treatment of entrapment of the median nerve in the wrist, we decided to treat chronic perineal pain by nerve blocks, and later by surgery. We describe here the clinical symptoms, the neurophysiological data, and the technique of the nerve blocks. For patients with persistent pain, we propose a posterior surgical approach which has provided successful pain relief in two third of patients.

[Chronic lower back pain: a new therapeutic approach]

Lower back pain is a common complaint of patients seen in our consultations. Despite progress, surgical procedures are still often unsuccessful in relieving pain. Blocks performed in the epidural spaces or more often in the articular facets have provided poor relief of chronic lower back pain. The pain has vegetative components. Considering anatomic findings, we describe the innervation of the peridiscal tIssues which suffer during degenarative conditions. We analyze the course of the autogenic nerves mediating lumbar pain, and select the site of the blocks necessary to obtain optimal selective pain relief. A well-defined block at the level of the communicating rami is described.

Tumor Necrosis Factor–Mediated E2F1 Suppression in Endothelial Cells

After balloon angioplasty, locally expressed tumor necrosis factor (TNF)-α disrupts endothelial cell (EC) proliferation and reendothelialization of the injured vessel. We have previously reported that TNF inhibits the EC cycle and downregulates the transcription factor E2F1. Ectopic expression of E2F1 at the site of injury improves reendothelialization of the injured vessel. In this study, we report that c-Jun N-terminal kinase (JNK) 1 and p38 mitogen-activated protein kinases (MAPKs) are differentially required for E2F1 expression and activity in ECs. Overexpression of constitutively active JNK1 mimicked TNF-mediated inhibitory events, whereas dominant-negative JNK1 prevented these effects. E2F cis elements in the promoter of E2F1 gene mediate suppressive actions of TNF, because removal of these sites rendered E2F1 promoter activity insensitive to TNF. JNK1 physically interacted with E2F1 and inactivated it via direct phosphorylation. Additionally, TNF inhibited Rb phosphorylation and dissociation from E2F1. Overexpression of constitutively active p38 MAPK facilitated Rb-E2F1 dissociation, whereas that of dominant-negative p38 MAPK did not. Taken together, these data suggest a differential requirement of JNK1 and p38 MAPK in TNF regulation of E2F1. Targeted inactivation of JNK1 at arterial injury sites may represent a potential therapeutic intervention for ameliorating TNF-mediated EC dysfunction.

Occipitocervical fixation with a single occipital clamp using inverted hooks

A simple occipitocervical osteosynthesis technique using cervical CCD (compact Cotrel-Dubousset) material is described in a clinical case. The originality of this technique consists in the occipital fastening used, involving the simultaneous insertion of two hooks into a single burr-hole. This greatly facilitated the positioning of the osteosynthesis rods, reduced surgical time, and provided immediate stability. These criteria are of considerable importance since this difficult surgical procedure is often performed in patients in a frail condition.