"Allograft-inflammatory-factor-1 is upregulated in microglial cells in human cerebral infarctions"

Alzheimer's-Associated Upregulation of Mitochondria-Associated ER Membranes After Traumatic Brain Injury

Traumatic brain injury (TBI) can lead to neurodegenerative diseases such as Alzheimer's disease (AD) through mechanisms that remain incompletely characterized. Similar to AD, TBI models present with cellular metabolic alterations and modulated cleavage of amyloid precursor protein (APP). Specifically, AD and TBI tissues display increases in amyloid-β as well as its precursor, the APP C-terminal fragment of 99 a.a. (C99). Our recent data in cell models of AD indicate that C99, due to its affinity for cholesterol, induces the formation of transient lipid raft domains in the ER known as mitochondria-associated endoplasmic reticulum (ER) membranes ("MAM" domains). The formation of these domains recruits and activates specific lipid metabolic enzymes that regulate cellular cholesterol trafficking and sphingolipid turnover. Increased C99 levels in AD cell models promote MAM formation and significantly modulate cellular lipid homeostasis. Here, these phenotypes were recapitulated in the controlled cortical impact (CCI) model of TBI in adult mice. Specifically, the injured cortex and hippocampus displayed significant increases in C99 and MAM activity, as measured by phospholipid synthesis, sphingomyelinase activity and cholesterol turnover. In addition, our cell type-specific lipidomics analyses revealed significant changes in microglial lipid composition that are consistent with the observed alterations in MAM-resident enzymes. Altogether, we propose that alterations in the regulation of MAM and relevant lipid metabolic pathways could contribute to the epidemiological connection between TBI and AD.

Allograft inflammatory factor-1 released from the cerebral microglia affect several organs in the body

Allograft inflammatory factor-1 (AIF-1) is expressed in microglia. Unilateral common carotid artery occlusion (UCCAO) was conducted to elucidate mechanisms that regulate AIF-1 expression in C57BL/6 male mice. Immunohistochemical reactivity of microglia against anti-AIF-1 antibody was increased significantly in the brain of this model. The increased AIF-1 production was further confirmed by ELISA using brain homogenate. Real-time PCR demonstrated that the increased AIF-1 production was regulated at the transcriptional level. Serum AIF-1 levels were further examined by ELISA and marked increase was observed on Day 1 of UCCAO. To examine the influence of AIF-1, immunohistochemical staining was performed and revealed that the immunoreactivity against anti-Iba-1 antibody was significantly increased in various organs. Among them, the accumulation of Iba-1⁺ cells were observed prominently in the spleen. Intraperitoneal injection of minocycline, a potent microglia inhibitor, reduced the number of Iba-1⁺ cells suggesting microglia activation-dependent accumulation. Based on these results, AIF-1 expression was further examined in the murine microglia cell line MG6. AIF-1 mRNA expression and secretion were up-regulated when the cells were cultured under hypoxic condition. Importantly, stimulation of the cells with recombinant AIF-1 induced the expression of AIF-1 mRNA. These results may suggest that increased AIF-1 production by microglia in cerebral ischemia regulate the AIF-1 mRNA expression at least in part by an autocrine manner.

Ionized Calcium Binding Adaptor Molecule 1 (IBA1)

OBJECTIVES

Ionized calcium binding adaptor molecule 1 (IBA1), a marker of microglia/macrophages, has not been investigated in human hematopathologic contexts. We evaluated its expression in mature and immature neoplasms of monocytic/histiocytic and dendritic cell (DC) origin.

METHODS

Immunohistochemistry for IBA1, CD14, CD68, and CD163 was performed on a total of 114 cases, including a spectrum of monocytic/histiocytic and DC neoplasms (20 tissue based and 59 bone marrow based) and several nonhistiocytic/monocytic/DC neoplasms as control groups (15 tissue based and 20 bone marrow based).

RESULTS

IBA1 expression was observed in all types of mature tissue-based histiocytic/DC neoplasms (20/20) but not in the corresponding control group (0/15). In bone marrow-based cases, IBA1 was expressed in most acute myeloid leukemias (AMLs) with monocytic differentiation (48/53), both blastic plasmacytoid dendritic cell neoplasms (2/2), and all chronic myelomonocytic leukemias (4/4), while it was positive in only one nonmonocytic AML (1/15) and none of the acute lymphoblastic leukemias (0/5). Collectively, IBA1 showed much higher sensitivity and specificity (93.7%, 97.1%) compared with CD14 (65.4%, 88.2%), CD68 (74.4%, 74.2%), and CD163 (52.6%, 90.6%).

CONCLUSIONS

IBA1 is a novel, highly sensitive, and specific marker for diagnosing neoplasms of monocytic/histiocytic and DC origin.

Immune Cell Infiltration into the Brain After Ischemic Stroke in Humans Compared to Mice and Rats: a Systematic Review and Meta-Analysis

Although several studies have suggested that anti-inflammatory strategies reduce secondary infarct growth in animal stroke models, clinical studies have not yet demonstrated a clear benefit of immune modulation in patients. Potential reasons include systematic differences of post-ischemic neuroinflammation between humans and rodents. We here performed a systematic review and meta-analysis to summarize and compare the spatial and temporal distribution of immune cell infiltration in human and rodent stroke. Data on spatiotemporal distribution of immune cells (T cells, macrophages, and neutrophils) and infarct volume were extracted. Data from all rodent studies were pooled by means of a random-effect meta-analysis. Overall, 20 human and 188 rodent stroke studies were included in our analyses. In both patients and rodents, the infiltration of macrophages and neutrophils preceded the lymphocytic influx. Macrophages and neutrophils were the predominant immune cells within 72 h after infarction. Although highly heterogeneously across studies, the temporal profile of the poststroke immune response was comparable between patients and rodents. In rodent stroke, the extent of the immune cell infiltration depended on the duration and location of vessel occlusion and on the species. The density of infiltrating immune cells correlated with the infarct volume. In summary, we provide the first systematic analysis and comparison of human and rodent post-ischemic neuroinflammation. Our data suggest that the inflammatory response in rodent stroke models is comparable to that in patients with stroke. However, the overall heterogeneity of the post-ischemic immune response might contribute to the translational failure in stroke research.

Differential expression of synaptic and interneuron genes in the aging human prefrontal cortex

Altered inhibition-excitation balance is implicated in brain aging. We hypothesized that expression of 14 genes encoding proteins localized to synapses or interneurons would show age-related changes relative to 1 another in postmortem tissue from the prefrontal cortex of 37 individuals (18-78 years) and that synaptic or interneuron markers would be differentially correlated with human brain volumes across aging. The majority of genes examined were differentially expressed with age, most being downregulated. Expression of 3 interneuron-related genes was significantly negatively associated with age (calbindin, somatostatin, cholecystokinin), whereas 3 synapse-related genes showed significant age-related expression change (PSD95, GAP43, VGLUT1). On covarying for 2 glial markers (GFAP, IBA1), all 3 interneuron genes and 1 synaptic gene (Growth-associated protein 43) remained significant. Two genes were significantly associated with total brain volume (calbindin, complexin 2) and a marker of synaptic density (synaptophysin) was significantly associated with cortical gray matter volume. Age-related change in expression of genes involved in maintenance of inhibition-excitation balance and regulation of prefrontocortical network dynamics suggests these pathways may contribute to brain aging.

Flow cytometric characterization of microglia in the offspring of PolyI:C treated mice

The neuropathology of schizophrenia has been reported to be closely associated with microglial activation. In a previous study, using the prenatal PolyI:C schizophrenia animal model, we showed an increase in cell numbers and a reduction in microglial branching in 30-day-old PolyI:C descendants, which suggests that there is microglial activation during adolescence. To provide more information about the activation state, we aimed to examine the expression levels of Iba1, which was reported to be up-regulated in activated microglia. We used a flow cytometric approach and investigated CD11b and CD45, two additional markers for the identification of microglial cells. We demonstrated that intracellular staining against Iba1 can be used as a reliable flow cytometric method for identification of microglial cells. Prenatal PolyI:C treatment had long-term effects on CD11b and CD45 expression. It also resulted in a trend towards increased Iba1 expression. Imbalance in CD11b, CD45, and Iba1 expression might contribute to impaired synaptic surveillance and enhanced activation/inflammatory activity of microglia in adult offspring.

A postnatal peak in microglial development in the mouse hippocampus is correlated with heightened sensitivity to seizure triggers

BACKGROUND

Explosive synaptogenesis and synaptic pruning occur in the hippocampus during the first two weeks of postnatal life, coincident with a heightened susceptibility to seizures in rodents. To determine the temporal correlation between microglial development and age-dependent susceptibility and response to seizures, we quantified developmental changes in basal microglia levels and seizure-induced microglial activation in the hippocampus of Cx3Cr1(GFP /+) transgenic mice.

METHODS

Basal levels of microglia were quantified in the hippocampi of Cx3Cr1(GFP /+) mice at P0, P5, P10, P15, P20, P25, P30, P40, and P60. Seizure susceptibility and seizure-induced microglial activation were assessed in response to febrile seizures (lipopolysaccharide followed by hyperthermia) and kainic acid-induced status epilepticus.

RESULTS

The density of microglia within the hippocampus increased rapidly after birth, reaching a peak during the second week of life - the age at which the animals became most vulnerable to seizure triggers. In addition, this peak of microglial development and seizure vulnerability during the second postnatal week represented the time of maximal seizure-induced microglia activation.

CONCLUSIONS

Overreactive innate immunity mediated by activated microglia may exacerbate acute injury to neuronal synapses and contribute to the long-term epileptogenic effects of early-life seizures. Anti-inflammatory therapy targeting excessive production of inflammatory mediators by activated microglia, therefore, may be an effective age-specific therapeutic strategy to minimize neuronal dysfunction and prevent increases in susceptibility to subsequent seizures in developing animals.

Maternal bisphenol a diet induces anxiety-like behavior in female juvenile with neuroimmune activation

Maternal Bisphenol A (BPA) diet triggers anxiety in rodents, but the underlying mechanism is still unclear. Accumulating epidemiological and experimental data have demonstrated that the anxiety is associated with aberrant neuroimmune response. In this study, we found that maternal BPA diet (MBD) exacerbated anxiety-like behavior in female juvenile mice, and the molecular evidence further showed that this behavioral phenotype was connected to the neuroimmune activation, such as elevated tumor necrosis factor alpha (TNF-α) and interleukin (IL)-6 levels in prefrontal cortex (PFC) rather than in peripheral blood, which indicated that neuroimmune response might be ascribed to neuroglial activation because activated neuroglia cells could secrete proinflammatory cytokines. Subsequently, we found that ionized calcium-binding adapter molecule (Iba)-1 as a selective marker for microglia and glial fibrillary acidic protein as a specific marker for astrocyte were significantly increased at transcriptional and translational levels, which confirmed the neuroglial activation in this model. Therefore, we conclude that MBD induces excessive anxiety-like behavior in female juvenile with elevated TNF-α and IL-6 levels, as well as activated microglia and astrocyte in PFC. Herein caution must be taken to prevent potential risks from MBD becuase exacerbated anxiety-like behavior in female juvenile by MBD may be a critical contribution for subsequent growth or mental disorders.

Experimental infection of suckling mice by subcutaneous inoculation with Oropouche virus

Oropouche virus, of the family Bunyaviridae, genus Orthobunyavirus, serogroup Simbu, is an important causative agent of arboviral febrile illness in Brazil. An estimated 500,000 cases of Oropouche fever have occurred in Brazil in the last 30 years, with recorded cases also in Panama, Peru, Suriname and Trinidad. We have developed an experimental model of Oropouche virus infection in neonatal BALB/c mouse by subcutaneous inoculation. The vast majority of infected animals developed disease on the 5th day post infection, characterized mainly by lethargy and paralysis, progressing to death within 10 days. Viral replication was documented in brain cells by in situ hybridization, immunohistochemistry and virus titration. Multi-step immunohistochemistry indicated neurons as the main target cells of OROV infection. Histopathology revealed glial reaction and astrocyte activation in the brain and spinal cord, with neuronal apoptosis. Spleen hyperplasia and mild meningitis were also found, without viable virus detected in liver and spleen. This is the first report of an experimental mouse model of OROV infection, with severe involvement of the central nervous system, and should become useful in pathogenesis studies, as well as in preclinical testing of therapeutic interventions for this emerging pathogen.

Neuroprotective effects of hydrogen saline in neonatal hypoxia-ischemia rat model

Cerebral hypoxia-ischemia (HI) represents a major cause of brain damage in the term newborn. This study aimed to examine the short and long-term neuroprotective effect of hydrogen saline (H(2) saline) using an established neonatal HI rat pup model. Seven-day-old rat pups were subjected to left common carotid artery ligation and then 90 min hypoxia (8% oxygen at 37 degrees C). H(2) saturated saline was administered by peritoneal injection (5 ml/kg) immediately and again at 8 h after HI insult. At 24 h after HI, the pups were decapitated and brain morphological injury was assessed by 2,3,5-triphenyltetrazolium chloride (TTC), Nissl, and TUNEL staining. Acute cell death, inflammation and oxidative stress were evaluated at 24 h by studying caspase-3 activity, MDA measurement as well as Iba-1 immunochemistry in the brain. At 5 weeks after HI, spontaneous activity test and Morris water maze test were conducted. We observed that H(2) saline treatment reduced the caspase activity, MDA, Iba-1 levels, the infarct ratio, and improved the long-term neurological and neurobehavioral functions. H(2) saline has potentials in the clinical treatment of HI and other ischemia-related cerebral diseases.

Genomic profiles of damage and protection in human intracerebral hemorrhage

Intracerebral hemorrhage (ICH) produces a high rate of death and disability. The molecular mechanisms of damage in perihematomal tissue in humans have not been systematically characterized. This study determines the gene expression profile and molecular networks that are induced in human perihematomal tissue through molecular analysis of tissue obtained from endoscopic clot evacuation. Differentially expressed genes and their cellular origin were confirmed in a mouse model of ICH. A total of 624 genes showed altered regulation in human ICH. Bioinformatic analysis shows that these genes form interconnected networks of proinflammatory, anti-inflammatory, and neuronal signaling cascades. Intracerebral hemorrhage evokes coordinated upregulation of proinflammatory signaling through specific cytokines and chemokines and their downstream molecular pathways. Anti-inflammatory networks are also induced by ICH, including annexins A1 and A2 and transforming growth factor beta (TGFbeta) and their intracellular cascades. Intracerebral hemorrhage downregulates many neuronal signaling systems, including the N-methyl-D-aspartic acid (NMDA) receptor complex and membrane ion channels. Select portions of these molecular networks were confirmed in the mouse, and the proteins in a subset of these networks localized to subsets of neurons, oligodendrocytes, or leukocytes. These inflammatory and anti-inflammatory networks interact at several key points in neutrophil signaling, apoptotic cell death, and protease responses, and indicate that secondary damage in ICH activates opposing molecular systems.

Accumulation of macrophage-like cells expressing NG2 proteoglycan and Iba1 in ischemic core of rat brain after transient middle cerebral artery occlusion

Although neurons and glia inevitably undergo degeneration in the core of ischemic lesions, many cells, particularly immune cells, infiltrate the core and survive in it. Such infiltrating cells may play certain roles in the regeneration and repair of damaged brain tissues. In this study, we characterized macrophage-like cells that accumulated in the ischemic core of a rat brain whose right middle cerebral artery was transiently occluded for 90 mins. Many of the accumulated macrophage-like cells expressed Iba1, a marker of macrophages/microglia, as well as NG2 chondroitin sulfate proteoglycan (NG2), which has been recognized as a marker of oligodendrocyte progenitor cells. Such macrophage-like cells were termed BINCs (brain Iba1(+)/NG2(+) cells) to distinguish them from NG2(-)/Iba1(+) or NG2(+)/Iba1(-) cells that were also present in the perilesion and the contralateral hemisphere. Electron microscopy showed the localization of NG2 along the plasma membrane of cells that had many phagosomes and irregular-shaped or reniform heterochromatin-rich nuclei, which are characteristics of monocytes/macrophages. Brain Iba1(+)/NG2(+) cells were highly proliferative and their number peaked at 7 days post-reperfusion. An immunoblot analysis of NG2 revealed the presence of two NG2s: one expressed by BINCs with a molecular weight of 300 kDa, and the other found in the contralateral hemisphere with a molecular weight of 290 kDa. Taken the various functions of NG2, BINCs may be involved in not only phagocytosis of degenerated cells but also the healing and regeneration of lesion cores.

Allograft inflammatory factor-1 and its immune regulation

The allograft inflammatory factor-1 (AIF-1) is a 17 kDa interferon-gamma (IFN-gamma) inducible Ca(2+)-binding EF-hand protein that is encoded within the HLA class III genomic region. Three proteins including ionized Ca(2+)-binding adaptor 1, microglia response factor-1, and daintain are identical with AIF-1. The expression of AIF-1 was mostly limited to the monocyte/macrophage lineage, and augmented by cytokines such as IFN-gamma. It was assumed that AIF-1 was a novel molecule involved in inflammatory responses, allograft rejection, as well as the activation and function of macrophages. However, it has been reported that AIF-1 is also expressed in macrophages and microglial cells in autoimmune diseases such as experimental autoimmune encephalomyelitis, neuritis and uveitis models, suggesting that AIF-1 may play a pivotal role in autoimmunity. In the present manuscript, the genomic and functional characteristics of AIF-1 family proteins as well as their immune regulatory effects are reviewed.

Potential roles of allograft inflammatory factor-1 in the pathogenesis of hemangiomas

Hemangiomas are benign tumors of the vascular endothelium and are the most common tumors of infancy. These tumors are characterized by an initial phase of rapid proliferation in the first months of life, which is followed, in most cases, by spontaneous slow involution. Despite their high prevalence, their detailed pathogenesis remains unknown. Recent studies suggest that immunity responses, inflammatory cells and their precursors, myeloid cells, play important roles in the growth and involution of hemangiomas. The allograft inflammatory factor-1 is a powerful gene that is involved in several kinds of inflammatory response-related diseases. Studies also show that it is implicated in angiogenesis, proliferation and differentiation of stem cells, and development of tumors. Taken all these evidences into consideration, we hypothesize that allograft inflammatory factor-1 plays potential roles in pathogenesis, proliferation and involution of hemangioma. Investigating the role of allograft inflammatory factor-1 in the proliferation and involution of hemangioma will lead to a better understanding of pathogenesis of this lesion. Furthermore, the subtle regulation of allograft inflammatory factor-1 in the involution of hemangiomas will help design a new anti-angiogenic therapy for some tumors.

Differential microglial regulation in the human spinal cord under normal and pathological conditions

As the primary intrinsic immune effector cells of the central nervous system, microglia are involved in virtually all pathological processes of the brain and spinal cord including inflammatory, neurodegenerative, traumatic, neoplastic and vascular diseases. Despite this important role, there is a lack of data concerning microglial distribution and protein expression in the human spinal cord. In this study, we immunohistochemically investigated 10 normal human spinal cords to establish reference data and compared these results with 15 pathological human spinal cords deriving from distinct pathologies. Each spinal cord was evaluated at eight different levels for three white and two grey matter areas for both constitutive (MHC-II, CD68, IL-16, AIF-1, LCA, CD4) and reactive (MRP-8, MRP-14) microglial antigens. Whereas previous studies revealed significant regional differences in microglial distribution and protein expression in human brain, normal spinal cord displayed a uniform expression pattern, reaching levels of up to 17% MHC-II positive cells of the total cell population. This datum formed the basis for the further evaluation of microglia expression levels in pathological spinal cords, where levels of up to 45% positive cells were observed. Our results represent important reference values for future neuropathological diagnostic and therapeutical approaches in spinal cord pathologies.

Expression of allograft inflammatory factor 1 in tissues from patients with systemic sclerosis and in vitro differential expression of its isoforms in response to transforming growth factor beta

OBJECTIVE

Allograft inflammatory factor 1 (AIF-1), a protein initially identified in chronically rejected rat cardiac allografts, is involved in the immune response and proliferative vasculopathy that occurs during allograft rejection. Three well-characterized isoforms of AIF-1 result from alternative messenger RNA (mRNA) splicing. We previously identified a strong association of systemic sclerosis (SSc) with a polymorphism in AIF-1 isoform 2. The purpose of this study was to investigate AIF-1 expression in affected tissues from patients with SSc and to examine the regulation of its isoforms by transforming growth factor beta (TGFbeta).

METHODS

AIF-1 in the skin and lung tissues of patients with SSc was analyzed by immunochemistry. AIF-1 isoform expression in response to TGFbeta and interferon-gamma stimulation was examined by quantitative polymerase chain reaction (PCR).

RESULTS

AIF-1 protein was present in affected vessels of the lung and skin lesions of patients with SSc. Quantitative PCR showed an average of 14-fold higher mRNA levels in affected SSc skin than in normal skin. Double-label immunofluorescence staining demonstrated that T cells, macrophages, and endothelial cells in affected tissues expressed AIF-1. Stimulation of peripheral blood mononuclear cells with TGFbeta caused a specific and significant increase in the expression of AIF-1 isoform 2 transcripts (P < 0.005), which was due to stabilization of AIF-1 isoform 2 mRNA.

CONCLUSION

These data suggest that AIF-1 plays an important role in the pathogenesis of SSc owing to its increased expression in affected tissues and to the specific stimulation of AIF-1 isoform 2 by TGFbeta.

Protein expression changes in the nucleus accumbens and amygdala of inbred alcohol-preferring rats given either continuous or scheduled access to ethanol

Chronic ethanol (EtOH) drinking produces neuronal alterations within the limbic system. To investigate changes in protein expression levels associated with EtOH drinking, inbred alcohol-preferring (iP) rats were given one of three EtOH access conditions in their home-cages: continuous ethanol (CE: 24h/day, 7days/week access to EtOH), multiple scheduled access (MSA: four 1-h sessions during the dark cycle/day, 5 days/week) to EtOH, or remained EtOH-naïve. Both MSA and CE groups consumed between 6 and 6.5g of EtOH/kg/day after the 3rd week of access. On the first day of EtOH access for the seventh week, access was terminated at the end of the fourth MSA session for MSA rats and the corresponding time point (2300h) for CE rats. Ten h later, the rats were decapitated, brains extracted, the nucleus accumbens (NAcc) and amygdala (AMYG) microdissected, and protein isolated for 2-dimensional gel electrophoretic analyses. In the NAcc, MSA altered expression levels for 12 of the 14 identified proteins, compared with controls, with six of these proteins altered by CE access, as well. In the AMYG, CE access changed expression levels for 22 of the 27 identified proteins, compared with controls, with 8 of these proteins altered by MSA, as well. The proteins could be grouped into functional categories of chaperones, cytoskeleton, intracellular communication, membrane transport, metabolism, energy production, or neurotransmission. Overall, it appears that EtOH drinking and the conditions under which EtOH is consumed, differentially affect protein expression levels between the NAcc and AMYG. This may reflect differences in neuroanatomical and/or functional characteristics associated with EtOH self-administration and possibly withdrawal, between these two brain structures.

Hsp70 overexpression sequesters AIF and reduces neonatal hypoxic/ischemic brain injury

Apoptosis is implicated in neonatal hypoxic/ischemic (H/I) brain injury among various forms of cell death. Here we investigate whether overexpression of heat shock protein (Hsp) 70, an antiapoptotic protein, protects the neonatal brain from H/I injury and the pathways involved in the protection. Postnatal day 7 (P7) transgenic mice overexpressing rat Hsp70 (Tg) and their wild-type littermates (Wt) underwent unilateral common carotid artery ligation followed by 30 mins exposure to 8% O(2). Significant neuroprotection was observed in Tg versus Wt mice on both P12 and P21, correlating with a high level of constitutive but not inducible Hsp70 in the Tg. More prominent injury was observed in Wt and Tg mice on P21, suggesting its continuous evolution after P12. Western blot analysis showed that translocation of cytochrome c, but not the second mitochondria-derived activator of caspase (Smac)/DIABLO and apoptosis-inducing factor (AIF), from mitochondria into cytosol was significantly reduced in Tg 24 h after H/I compared with Wt mice. Coimmunoprecipitation detected more Hsp70 bound to AIF in Tg than Wt mice 24 h after H/I, inversely correlating with the amount of nuclear, but not cytosolic, AIF translocation. Our results suggest that interaction between Hsp70 and AIF might have reduced downstream events leading to cell death, including the reduction of nuclear AIF translocation in the neonatal brains of Hsp70 Tg mice after H/I.

Gene expression profiling in chronic inflammatory demyelinating polyneuropathy

Gene expression in archived frozen sural nerve biopsies of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) was compared to that in vasculitic nerve biopsies (VAS) and to normal nerve (NN) by DNA microarray technology. Hierarchical clustering analysis demonstrated distinct gene expression patterns distinguishing these disease groups. Of particular interest were: (1) Tachykinin precursor 1, which may be involved in pain mediation; (2) Stearoyl-CoA-desaturase, which may be a marker for remyelination and (3) the Allograft Inflammatory Factor 1 (AIF-1), a modulator of immune response during macrophage activation. Differential gene expression may help distinguish between CIDP, VAS and NN in sural nerve biopsies and identify genes that may be involved in disease pathogenesis.

Infiltrating CD14+ monocytes and expression of CD14 by activated parenchymal microglia/macrophages contribute to the pool of CD14+ cells in ischemic brain lesions

CD14, a key pattern recognition receptor of the innate immune system, is a surface molecule on monocytic cells involved in cellular activation. We investigated 18 autopsy cases of focal cerebral infarctions (FCI) by immunohistochemistry to examine CD14 expression following ischemia. Controls confirmed constitutive CD14 expression by few perivascular cells. In contrast to quiescent CD14- parenchymal microglial cells, following ischemia activated microglia/macrophages expressed abundant CD14. In FCI, CD14+ cells increased both in perivascular spaces and in brain parenchyma within 1-2.5 days and remained elevated until late stages. Early CD14 expression suggests an essential part of CD14 in the acute inflammatory response following stroke.