Beta-chemokine receptor expression in idiopathic inflammatory myopathies

Beta-chemokines attract and activate T cells and monocytes and have a key role in chronic inflammation. Certain beta-chemokines, such as monocyte chemoattractant protein-1 (MCP-1), have been reported to be upregulated in the idiopathic inflammatory myopathies (IIM). We studied the distribution of beta-chemokine receptors in polymyositis (PM), sporadic inclusion-body myositis (sIBM), dermatomyositis (DM), and control samples. CCR1-5 were localized to blood vessels in all samples. In addition, increased endothelial expression of CCR2A was observed in IIM. Subsets of inflammatory cells, identified as macrophages and T cells, in all three types of IIM expressed CCR2A, CCR2B, CCR3, CCR4, and CCR5. In contrast to an earlier report, we found CCR2B to be the most prominent MCP-1 receptor on inflammatory cells in IIM, especially in PM and sIBM. Strong CCR4 expression was present on myonuclei of regenerating muscle fibers. The prominence of the CCR2 receptors further underlines the importance of the interaction with their ligand MCP-1 in the immunopathogenesis of IIM and puts CCR2B forward as a potential target for future therapeutic intervention.     

Local expression of cytokines in idiopathic inflammatory myopathies

H. Lepidi, V. Frances, D. Figarella-Branger, C. Bartoli, A. Machado-Baeta & J-F. Pellissier (1998) Neuropathology and Applied Biology , 24, 73–79
Local expression of cytokines in idiopathic inflammatory myopathies
The idiopathic inflammatory myopathies (IIM), including dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM), are regarded as autoimmune diseases. They are characterized by chronic lymphocytic and macrophagic infiltration in muscle tissue. Of particular importance in understanding the immune response to IIM is the specific pattern of locally produced cytokines. Frozen muscle tissues from IIM (5 DM, 3 PM, and 1 IBM) were used to investigate the cytokine responses. The RT-PCR technique was instrumental to determine the pattern of expression of pro-inflammatory (IL-1β, IL-6, TNF-α), Th1 (IFN-γ IL-2), and Th2 (IL-4) cytokines. Immunohistochemistry was also used to localize morphologically IFN-γ and IL-4. Our results show that pro-inflammatory cytokines and Th1 cytokines are mainly expressed in IIM. The accumulation of mononuclear inflammatory cells and the inflammatory syndrome in IIM are probably related in part to the production of pro-inflammatory cytokines. Moreover, the pattern of local cytokine expression is consistent with a Th1 immune response related to autoimmune diseases.     

Monocyte chemoattractant protein 1 is responsible for macrophage recruitment following injury to sciatic nerve

Following injury to the peripheral nervous system, circulating monocytes/macrophages are recruited to the damaged tissue, where they play vital roles during both nerve degeneration and subsequent regeneration. Monocyte chemoattractant protein-1 (MCP-1), a member of the C-C or β-chemokine family, is a powerful leukocyte recruitment/activation factor that is relatively specific for monocytes/macrophages. Because these are the predominant leukocyte type recruited by injured nerve, we hypothesized that up-regulation of MCP-1 expression is involved in recruitment of these cells. Indeed, assay of steady-state levels of MCP-1 mRNA in rat sciatic nerve during tellurium-induced primary demyelination indicated up-regulation of this chemokine with a peak after 3 days of tellurium exposure, preceding the peak of accumulation of phagocytic macrophages (assayed as lysozyme mRNA levels) by 6 days. Increasing levels of MCP-1 mRNA expression, induced by increasing levels of tellurium exposure, resulted in corresponding increases in subsequent recruitment of macrophages. In situ hybridization suggested that MCP-1 mRNA was localized in Schwann cells. No expression of MIP-2, which is a C-X-C or α-chemokine that is specific for recruitment of neutrophils, was detected, consistent with the lack of recruitment of significant numbers of these cells. In addition, we also investigated the response seen following nerve transection (axonal degeneration and secondary demyelination with no subsequent regeneration) and nerve crush (degeneration followed by regeneration). In these latter two nerve injury models, there was also a marked, early up-regulation of MCP-1 mRNA, with a time course that is compatible with a role for this chemokine in macrophage recruitment. We conclude that MCP-1 is involved in recruiting monocytes/macrophages to injured peripheral nerve and that the specificity of leukocyte types recruited results from specificity of chemokine production. J. Neurosci. Res. 53:260–267, 1998. © 1998 Wiley-Liss, Inc.     

Monocyte chemoattractant protein 1 and chemokine receptor CCR2 productions in Guillain-Barré syndrome and experimental autoimmune neuritis

Infiltration of activated lymphocytes and monocytes is a key phenomenon in the pathogenesis of Guillain-Barré syndrome (GBS) and experimental autoimmune neuritis (EAN). To investigate the role of chemokines, we determined the blood and nerve tissue expression of monocyte chemoattractant protein 1 (MCP-1), a major chemoattractant of monocytes and activated lymphocytes, and its receptor CCR2 in GBS and EAN. MCP-1 circulating levels (ng/ml) in GBS were increased at the time of progression, peaked at the time of plateau and normalized with recovery. MCP-1 circulating levels were the highest in the most disabled patients. The number of circulating CCR2 positive cells was lower in patients with GBS than in healthy subjects (p<0.004). In GBS, MCP-1 expression was observed in epineurial and endoneurial vessels, on infiltrating cells, Schwann cells and in the endoneurial extracellular matrix. Some CCR2 positive cells were observed in nerve biopsies of GBS patients. In EAN, a slight positivity for MCP-1 was observed in the sciatic nerve. There was no circulating CCR2 positive cells. However, at the time of plateau, a conspicuous infiltration of CCR2 positive cells was observed in the sciatic nerve that was no longer observed at the time of recovery. These results suggest that MCP-1 and CCR2 may participate to the recruitment of circulating mononuclear cells in nerve tissue in EAN and GBS.     

Expression of adhesion molecules and monocyte chemoattractant protein-1 (MCP-1) in the spinal cord lesions in HTLV-I-associated myelopathy

Leukocyte adhesion molecules to endothelium plays an important role in the pathogenesis of inflammatory diseases, including HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). To help define the role of adhesion molecules in HAM/TSP, we studied the expression of lymphocyte function-associated antigen-1 (LFA-1), Mac-1, very late antigen-4 (VLA-4), Sialyl Lewis^x (SLex), intercelluar adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), endothelial leukocyte adhesion molecule-1 (ELAM-1) and monocyte chemoattractant protein-1 (MCP-1) in the spinal cord lesions of HAM/TSP. The results indicate that spinal cord lesions of HAM/TSP have greater VCAM-1 expression on endothelium compared with those of controls. Infiltrating mononuclear cells, especially perivascular lesions, expressed VLA-4. Although the expression of ICAM-1 in the spinal cords was not distinctive between HAM/TSP and controls, infiltrating mononulcear cells in the spinal cords of HAM/TSP strongly expressed LFA-1 and Mac-1. ELAM-1 was expressed on endothelium in the inactive-chronic lesions from three of five HAM/TSP, but was not detectable in the spinal cords of controls. SLex reaction was detectable on occasional perivascular cells in the spinal cord of HAM/TSP, but not in those of controls. MCP-1 was detectable on perivascular infiltrating cells and vascular endothelium in active-chronic lesions. This study suggests that VLA-4/VCAM-1 interaction may play an important role for lymphocyte migration into the central nervous system (CNS), and MCP-1 may also be involved in inflammatory cell recruitment to the CNS in HAM/TSP. Received: 4 September 1995 / Revised, accepted: 23 October 1995     

Clinical and serological characteristics of 125 Dutch myositis patients

The idiopathic inflammatory myopathies (IIM) are a heterogeneous group of systemic diseases that include the familiar disease entities of dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM). A subset of patients has unique autoantibodies which are specific for IIM (myositis specific autoantibodies; MSAs). We studied the clinical and serological characteristics of IIM in 125 Dutch patients. Sera were analysed by immunoblotting, enzyme-linked immunosorbent assay, and immunoprecipitation. The most frequently encountered MSA was the anti-Jo-1 autoantibody (20%), followed by anti-tRNAHis (6%), anti-Mi-2 (6%), and anti-SRP (4%). The presence of certain MSAs was clearly associated with specific clinical characteristics. Anti-Jo-1 and anti-tRNAHis were associated with the anti-synthetase syndrome, anti-SRP with PM with severe myalgia and arthralgia and a moderate response to immunosuppressive treatment. A novel finding was the presence of anti-Mi-2, not only in DM, but also in PM. MSAs were frequently present in DM/PM sera, but were hardly ever detected in the sera of IBM patients. The few IBM patients with MSAs demonstrated a significant response to immunosuppressive treatment. It can be concluded that MSAs define specific clinical syndromes within the spectrum of IIM and that they can assist in the differential diagnosis and treatment plan of these enigmatic disorders by virtually excluding IBM by their presence, and by potentially identifying a subgroup of steroid-responsive IBM patients.     

Regulation of monocyte chemoattractant protein-1 expression in adult human non-neoplastic astrocytes is sensitive to tumor necrosis factor (TNF) or antibody to the 55-kDa TNF receptor

Infiltration of the central nervous system (CNS) by monocytes is a characteristics of many non-malignant disease processes, although the signals regulating such traffic are unclear. Tumor necrosis factor (TNF) and other inflammatory cytokines have been shown to elicit production of monocyte chemoattractant activity in glioma cells, but the regulation of such activity in non-neoplastic adult astrocytes has not been examined. We previously observed that TNF constituted a proliferative signal for non-neoplastic adult human astrocytes in vitro involving the 55-kDa TNF receptor. In the present study, we demonstrate that TNF exposure enhances the expression of monocyte chemoattractant protein-1 (MCP-1) mRNA and functional monocyte chemoattractant activity in non-neoplastic astrocytes. Results indicated that MCP-1 mRNA expression was maximal within 3 h, and was further augmented by the protein synthesis inhibitor cycloheximide (CY). Antibody (htr-9) directed against the 55-kDa TNF receptor also elicited MCP-1 mRNA expression while antibody to the 75-kDa TNF receptor (utr-1) was ineffective. Secretion of monocyte chemoattractant activity was significantly greater in TNF- or htr-9-treated astrocytes than in utr-1-treated or untreated controls; activity was abolished by treatment with antibody to MCP-1. These findings suggest that non-neoplastic adult human astrocytes may contribute to CNS inflammatory responses by mediating recruitment of peripheral blood monocytes.     

Chemokine regulation of macrophage recruitment into the olfactory epithelium following target ablation: involvement of macrophage inflammatory protein-1alpha and monocyte chemoattractant protein-1

Target ablation by olfactory bulbectomy synchronizes the degenerative cell death of olfactory receptor neurons (ORNs), infiltration of macrophages, and proliferation of progenitor cells, leading to neurogenesis, ORN replacement, and regeneration of the sensory epithelium. Although macrophages participate in the degenerative and regenerative events, little is known of the molecular and cellular mechanisms associated with their recruitment during the earliest period following target ablation. Macrophage inflammatory protein-1alpha (MIP-1alpha) and monocyte chemoattractant protein-1 (MCP-1), which are members of the CC or beta-chemokine subfamily, are chemoattractants for monocytes/macrophages. Shortly after target ablation, the protein and mRNA levels for MIP-1alpha and MCP-1 were up-regulated, showing peak expression levels from 16 hr to 3 days post-OBX; this coincided with the pattern of infiltration of activated F4/80(+) macrophages. The mRNAs for MIP-1alpha and MCP-1, as well as their cognate receptors CCR1 and CCR2, respectively, were localized in resident and infiltrating macrophages in numbers commensurate with those of F4/80-immunopositive macrophages in adjacent tissue sections. The mRNA(+) macrophages were localized within olfactory epithelial compartments that corresponded with their proposed functions associated with phagocytosis, proliferation, and infiltration. Our data support the hypothesis that MIP-1alpha and MCP-1 are chemoattractant chemokines associated with the recruitment of macrophages into the olfactory epithelium shortly after target ablation.     

Interferon-beta treatment alters peripheral blood monocytes chemokine production in MS patients

Chemokines direct the recruitment of leukocytes to inflammatory sites and may also participate in the regulation of cytokine production by naive T helper cells. Chemokine production by blood monocytes was investigated by intracytoplasmic staining in interferon-beta (IFN-beta)-treated multiple sclerosis (MS) patients, untreated MS patients, and healthy controls. Under unstimulated conditions, no differences in the production of interleukin-8 (IL-8), IFN-inducible protein 10 (IP-10), monokine induced by interferon-gamma (Mig), monocyte chemoattractant protein-1 (MCP-1), and monocyte chemoattractant protein-3 (MCP-3) were seen between untreated MS patients and controls. Chemokine production by monocytes following T cell activation was decreased in MS patients taking IFN-beta compared to controls and untreated MS patients. Unlike other chemokines, macrophage inflammatory protein-1alpha (MIP-1alpha) production by monocytes was significantly decreased in untreated MS patients compared to controls, and IFN-beta treatment increased MIP-1alpha expression to the level seen in controls. In vitro addition of IFN-beta1b to peripheral blood mononuclear cells (PBMC) cultures tended to decrease the production of IL-8, IP-10, Mig, MCP-1, and MCP-3, but not of MIP-1alpha. These findings suggest that IFN-beta treatment may have a differential affect on chemokine production by monocytes. Longitudinal studies must be done to confirm these observations.     

HIV-1 Tat protein upregulates inflammatory mediators and induces monocyte invasion into the brain

Impaired inflammatory functions may be critical factors in the mechanisms by which HIV-1 enters the CNS. Evidence indicates that a viral gene product, the protein Tat, can markedly contribute to these effects. In the present study we tested the hypothesis that Tat can upregulate the expression of inflammatory cytokines and adhesion molecules and facilitate the entry of monocytes into the brain. Expression of inflammatory mediators such as monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-alpha), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) was assessed in C57BL/6 mice injected with Tat(1-72) into the right hippocampus. In the Tat(1-72)-injected groups, mRNA and protein levels of MCP-1, TNF-alpha, VCAM-1, and ICAM-1 were markedly elevated compared to those in control animals. The most pronounced changes were observed in and around the injected hippocampus. Double-labeling immunohistochemistry demonstrated that inflammatory proteins were primarily expressed in activated microglial cells and perivascular cells. In addition, astrocytes and endothelial cells were susceptible to Tat(1-72)-induced inflammatory responses. These changes were associated with a substantial infiltration of monocytes into the brain. These data demonstrate that intracerebral administration of Tat can induce profound proinflammatory effects in the brain, leading to monocyte infiltration.     

Brain cytokine synthesis induced by an intraparenchymal injection of LPS is reduced in MCP-1-deficient mice prior to leucocyte recruitment

We have previously shown that ischaemic lesions are smaller in monocyte chemoattractant protein-1-deficient (MCP-1(-/-)) mice than in wild-type (wt) controls. In addition to its role as a monocyte chemoattractant, monocyte chemoattractant protein-1 (MCP-1) has been proposed to contribute to lesion progression after focal ischaemia by driving local cytokine synthesis by resident glia. To investigate this hypothesis we injected lipopolysaccharide (LPS) into the brain parenchyma of MCP-1(-/-) mice and compared the resulting inflammatory response and production of proinflammatory cytokines to those in wt mice. Microglial and astrocyte morphological activation was the same in the two strains, but MCP-1(-/-) mice showed significantly lower levels of proinflammatory cytokine synthesis; interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) levels were up to 50% lower than in wt controls after 6 h. This reduced synthesis of proinflammatory cytokines occurred well before leucocyte recruitment to the central nervous system (CNS) is observed in this model of acute inflammation and thus cannot be attributed to lower numbers of recruited monocytes at the site of injury. We propose that MCP-1 contributes to acute CNS inflammation by pleiotropic mechanisms. In addition to being a potent chemoattractant for monocytes, we provide evidence here that MCP-1 can modify the responsiveness of CNS glia to acute inflammatory stimuli prior to leucocyte recruitment, thereby acting as a priming stimulus for cytokine synthesis in cells such as microglia.     

Overexpression of monocyte chemoattractant protein 1 in the brain exacerbates ischemic brain injury and is associated with recruitment of inflammatory cells.

Brain cells produce cytokines and chemokines during the inflammatory process after stroke both in animal models and in patients. Monocyte chemoattractant protein 1 (MCP-1), one of the proinflammatory chemokines, can attract monocytes to the tissue where MCP-1 is overexpressed. However, the role of MCP-1 elevation in stroke has not been explored in detail. The authors hypothesized that elevated MCP-1 levels would lead to increased influx of monocytes and increased brain infarction size in stroke induced by middle cerebral artery occlusion with partial reperfusion. There were no differences in blood pressure, blood flow, or vascular architecture between wild-type mice and transgenic MBP-JE mice. Twenty-four to 48 hours after middle cerebral artery occlusion, brain infarction volumes after ischemia were significantly larger in MBP-JE mice than in wild-type controls and were accompanied by increased local transmigration and perivascular accumulation of macrophages and neutrophils. These results indicate that MCP-1 can contribute to inflammatory injury in stroke.     

Changes in CSF acetyl- and butyrylcholinesterase activity after long-term treatment with AChE inhibitors in Alzheimer's disease

Jain A, Sharma MC, Sarkar C, Bhatia R, Singh S, Gulati S, Handa R. Detection of the membrane attack complex as a diagnostic tool in dermatomyositis.
Acta Neurol Scand: 2011: 123: 122–129.
© 2010 John Wiley & Sons A/S. Background – Currently there is no reliable diagnostic marker to distinguish between the subgroups of idiopathic inflammatory myopathies (IIMs), i.e. dermatomyositis (DM), polymyositis (PM) and inclusion body myositis (IBM). Membrane attack complex (MAC) has been shown to be involved in the pathogenesis of dermatomyositis but its role as a diagnostic marker has not been evaluated. Aim – To assess the diagnostic utility of MAC deposition in distinguishing dermatomyositis from other neuromuscular disorders. Material and methods – Immunohistochemical detection of MAC deposition on endomysial microvessels was carried out on 127 muscle biopsies comprising of 21 cases of dermatomyositis, 42 other IIMs and 64 non‐IIM neuromuscular diseases. Results – MAC deposition showed a high sensitivity (80.9%) and specificity (85%) to differentiate DM from other IIMs. Its specificity was higher (98.4%) in discriminating DM from non‐IIM muscular diseases and IIM from non‐IIMs. Conclusion – MAC deposition can serve as a reliable marker to distinguish DM from other IIMs (i.e. PM and IBM) as well as from non‐IIM diseases. It can also serve as a useful adjunct in diagnosis of IIMs when there is diagnostic dilemma with their morphologic similarities. These results provide further credence to the long‐standing view that MAC‐mediated capillary destruction is involved in the immunopathogenesis of DM.     

Early and specific expression of monocyte chemoattractant protein-1 in the thalamus induced by cortical injury

For many years it has been known that retrograde degeneration of thalamic neurons occurs following damage to the cerebral cortex, however, the molecular mechanisms which control this process are unknown. Recent studies have demonstrated microglial activation in thalamic nuclei well before the onset of retrograde neuronal cell death. Activated monocytes and microglia synthesize factors detrimental to neuronal survival as well as phagocytose damaged and dying neurons. Our previous studies demonstrated that monocyte chemoattractant protein-1 (MCP-1), a β chemokine which attracts cells of monocytic origin to sites of injury, is rapidly expressed in the brain following visual cortical lesions. The present study examined the expression of MCP-1 messenger RNA and protein in the thalamus following a visual cortical lesion. Aspiration lesions of visual cortex were made in adult mice. At specific times after lesion, brains were harvested and dissected into specific regions. MCP-1 message as detected using northern analysis was absent in uninjured brain, but was elevated in the ipsilateral thalamus as rapidly as 1 h following the lesion. In situ hybridization localized MCP-1 message to subpial glial cells of the lateral geniculate nucleus (LGN) of the ipsilateral thalamus after injury. ELISA showed that MCP-1 protein levels were significantly elevated in the ipsilateral thalamus at 6 h, peaked at 12 h, and remained above baseline levels for at least 1 week post lesion. In addition, anti-GFAP staining demonstrated activated astrocytes localized to the ipsilateral LGN at 24 and 72 h after injury. The early expression and regional localization of MCP-1 mRNA and protein strongly suggest that MCP-1 is a critical molecule in the regulation of thalamic retrograde neuronal degeneration.     

Induction of beta-chemokine secretion by human brain microvessel endothelial cells via CD40/CD40L interactions

beta-chemokines play an important role during the course of central nervous system (CNS) inflammation. Using primary cultures of human cerebral microvascular endothelial cells, we detected increased monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation normal T cell expressed and secreted (RANTES) production following incubation with soluble CD40L. These results suggest a potential mechanism by which activated CD40L positive T cells may enhance beta-chemokine expression and thus influence the recruitment of mononuclear cells across the human blood-brain barrier.     

颈动脉粥样硬化斑块内MCP-1表达的研究

目的观察颈动脉粥样硬化(AS)斑块内单核细胞趋化蛋白-1(MCP-1)的mRNA和抗原的表达情况。方法分别应用原位杂交和免疫组织化学法测定颈AS斑块中MCP-1mRNA和抗原表达。结果相对于正常动脉内膜,颈AS病变内膜MCP-1阳性细胞数明显增多(P<0.05)。其中颈AS严重病变肩区阳性细胞数最多,以单核-巨噬细胞为主。结论MCP-1与颈AS发生密切相关。     

Tumor necrosis factor-α expression in muscles of polymyositis and dermatomyositis

We evaluated the expression of tumor necrosis factor-α (TNF-α) mRNA in muscle biopsy specimens from patients with polymyositis (PM) and dermatomyositis (DM) to clarify its role in the pathogenesis of PM and DM. We performed non-radioactive in situ hybridization studies for TNF-α combined with immunohistochemistry for cell type-specific markers on muscles from ten PM and five DM patients. TNF-α-positive infiltrating cells present in the endomysium and perimysium were found in all PM and DM muscles. The frequency of TNF-α-positive cells against total infiltrating cells was similar among PM and DM (27.1 ± 7.4% in PM and 28.5 ± 13.6% in DM). However, TNF-α/CD8-positive lymphocytes and TNF-α-positive macrophages invading the non-necrotic muscle fiber were observed only in PM but not in DM. TNF-α was more highly expressed in PM and DM than was previously thought, and it was suggested that TNF-α plays a role in muscle fiber degeneration in PM. Received: 9 June 1999 / Revised, accepted: 25 October 1999