Membrane signaling by complement C5b-9, the membrane attack complex

Nicholson‐Weller, Anne; Halperin, José A.

doi:10.1007/bf02918256

Cited by 142 publications

(116 citation statements)

References 68 publications

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“…The pore allows free movement of molecules in and out of the cell, since it has a hydrophilic internal face that allows the passage of water. Important for this work, Ca 2ϩ influx has been shown to be one of the general consequences of MAC activation (48), resulting in Ca 2ϩ oscillations that have been shown to last up to 45 min, in oligodendrocytes (49). In muscle cells, Jackson et al (50) have shown using patchclamp analysis of individual MAC channels, that these pores rapidly change between conducting and non-conducting states.…”

Section: Discussionmentioning

confidence: 99%

Sublytic Membrane-Attack-Complex (MAC) Activation Alters Regulated Rather than Constitutive Vascular Endothelial Growth Factor (VEGF) Secretion in Retinal Pigment Epithelium Monolayers

Kunchithapautham

Rohrer

2011

Journal of Biological Chemistry

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Uncontrolled activation of the alternative complement pathway and secretion of vascular endothelial growth factor (VEGF) are thought to be associated with age-related macular degeneration (AMD). Previously, we have shown that in RPE monolayers, oxidative-stress reduced complement inhibition on the cell surface. The resulting increased level of sublytic complement activation resulted in VEGF release, which disrupted the barrier facility of these cells as determined by transepithelial resistance (TER) measurements. Induced rather than basal VEGF release in RPE is thought to be controlled by different mechanisms, including voltage-dependent calcium channel (VDCC) activation and mitogenactivated protein kinases. Here we examined the potential intracellular links between sublytic complement activation and VEGF release in RPE cells challenged with H 2 O 2 and complement-sufficient normal human serum (NHS). Disruption of barrier function by H 2 O 2 ؉ NHS rapidly increased Ras expression and Erk and Src phosphorylation, but had no effect on P38 phosphorylation. Either treatment alone had little effect. TER reduction could be attenuated by inhibiting Ras, Erk and Src activation, or blocking VDCC or VEGF-R2 activation, but not by inhibiting P38. Combinatorial analysis of inhibitor effects demonstrated that sublytic complement activation triggers VEGF secretion via two pathways, Src and Ras-Erk, with the latter being amplified by VEGF-R2 activation, but has no effect on constitutive VEGF secretion mediated via P38. Finally, effects on TER were directly correlated with release of VEGF; and sublytic MAC activation decreased levels of zfp36, a negative modulator of VEGF transcription, resulting in increased VEGF expression. Taken together, identifying how sublytic MAC induces VEGF expression and secretion might offer opportunities to selectively inhibit pathological VEGF release only.

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Section: Discussionmentioning

confidence: 99%

Sublytic Membrane-Attack-Complex (MAC) Activation Alters Regulated Rather than Constitutive Vascular Endothelial Growth Factor (VEGF) Secretion in Retinal Pigment Epithelium Monolayers

Kunchithapautham

Rohrer

2011

Journal of Biological Chemistry

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“…1). Nucleated cells require multiple C5b-9 lesions for lysis, whereas at lower doses C5b-9 induces sublethal (sublytic) injury (83,94,116). The response of a cell, including the GEC, to sublytic doses of C5b-9 attack is not simply due to disruption of the plasma membrane but rather to the activation of specific signaling pathways.…”

Section: Signaling Pathways Activated By Assembly Of C5b-9mentioning

confidence: 99%

Experimental membranous nephropathy redux

Cybulsky

Quigg²,

Salant³

2005

American Journal of Physiology-Renal Physiology

112

133

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Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. Active and passive Heymann nephritis (HN) in rats are valuable experimental models because their features so closely resemble human MN. In HN, subepithelial immune deposits form in situ as a result of circulating antibodies. Complement activation leads to assembly of C5b-9 on glomerular epithelial cell (GEC) plasma membranes and is essential for sublethal GEC injury and the onset of proteinuria. This review revisits HN and focuses on areas of substantial progress in recent years. The response of the GEC to sublethal C5b-9 attack is not simply due to disruption of the plasma membrane but is due to the activation of specific signaling pathways. These include activation of protein kinases, phospholipases, cyclooxygenases, transcription factors, growth factors, NADPH oxidase, stress proteins, proteinases, and others. Ultimately, these signals impact on cell metabolic pathways and the structure/function of lipids and key proteins in the cytoskeleton and slit-diaphragm. Some signals affect GEC adversely. Thus C5b-9 induces partial dissolution of the actin cytoskeleton. There is a decline in nephrin expression, reduction in F-actin-bound nephrin, and loss of slit-diaphragm integrity. Other signals, such as endoplasmic reticulum stress, may limit complement-induced injury, or promote recovery. The extent of complement activation and GEC injury is dependent, in part, on complement-regulatory proteins, which act at early or late steps within the complement cascade. Identification of key steps in complement activation, the cellular signaling pathways, and the targets will facilitate therapeutic intervention in reversing GEC injury in human MN.

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“…The MAC forms a macromolecular pore capable of inserting itself into cell membranes and lysing heterologous cells, including bacteria and viruses. 15 MAC formation in autologous cell membrane plays multiple and complex functions. 16 Sublytic MAC in endothelial and smooth muscle cells is also an important mediator of cellular signals that trigger mitogenic effects 17 and release growth factors such as basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF), as well as cytokines such as IL-1 and monocyte chemotactic protein-1 (MCP-1).…”

mentioning

confidence: 99%

The Protective Role of CD59 and Pathogenic Role of Complement in Hepatic Ischemia and Reperfusion Injury

Zhang

Xing

et al. 2011

The American Journal of Pathology

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Hepatic ischemia-reperfusion injury (IRI) is a major factor influencing graft outcome in liver transplantation, but its mechanism is not well defined. Although complement, including the membrane attack complex (MAC), a terminal product of complement activation, is thought to be involved in the multiple reactions subsequent to the ischemia-reperfusion (IR) process, the role of MAC in the pathogenesis of hepatic IRI requires further investigation. We used a warm ischemia-reperfusion injury model in mice and a syngeneic orthotopic liver transplantation model in rats to define the role of complement, including MAC, in hepatic IR. CD59-deficient mice had more severe liver dysfunction, evidenced by increased aspartate aminotransferase levels and increased injury of liver parenchymal and nonparenchymal cells than did CD59-sufficient mice during warm hepatic IR. Furthermore, complement depletion in CD59-deficient mice by pretreatment with cobra venom factor (CVF) or the genetic introduction of C3 deficiency partially protected against development of the severe liver dysfunction that occurred in CD59-deficient mice. Severity of liver dysfunction correlated with MAC deposition, apoptotic cells, and increased inflammatory mediators such as tumor necrosis factor ␣. Liver transplantation is a routine and powerful approach for treatment of patients with acute or chronic liver failure of various causes. 1 Nevertheless, hepatic ischemia-reperfusion (IR) remains a major deleterious factor influencing graft outcome in organ transplantation. The incidence of primary graft failure (5% to 15%) and initial poor function (10% to 25%) is strongly dependent on the extent of ischemia-reperfusion injury (IRI). 2-4 IRI also initiates later graft failure by triggering irreversible intrahepatic biliary tract injury (ischemic-type biliary lesion) or by promoting rejection through activation of innate immunity. 5 At present, because of the shortage of organs for transplantation, the donor pool has been expanded by utilization of marginal organs from old donors or non-heart-beating donors, as well as grafts with prolonged cold storage, and even allografts donated after cardiac death. It is conceivable that grafts from such donors could cause severe liver injury, because they have usually experienced a long ischemia time. To improve the outcome of liver transplantation, therefore, it is imperative to better understand the mechanisms involved in IRI and to design novel therapeutic strategies for prevention of IRI.Ischemia-reperfusion injury is characterized by the presence of activated polymorphonuclear leukocytes, oxygen radical formation, 6 and cytokine release. 7,8 The process that temporarily blocks blood supply followed by blood reperfusion to the living donor after the transplantation causes attraction, activation, adhesion, and migration of neutrophils at the site of donor organ, thereby

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Membrane signaling by complement C5b-9, the membrane attack complex

Cited by 142 publications

References 68 publications

Sublytic Membrane-Attack-Complex (MAC) Activation Alters Regulated Rather than Constitutive Vascular Endothelial Growth Factor (VEGF) Secretion in Retinal Pigment Epithelium Monolayers

Sublytic Membrane-Attack-Complex (MAC) Activation Alters Regulated Rather than Constitutive Vascular Endothelial Growth Factor (VEGF) Secretion in Retinal Pigment Epithelium Monolayers

Experimental membranous nephropathy redux

The Protective Role of CD59 and Pathogenic Role of Complement in Hepatic Ischemia and Reperfusion Injury

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