Properdin Deficiency Impairs Phagocytosis and Enhances Injury at Kidney Repair Phase Post Ischemia-Reperfusion.

Properdin, a positive regulator of complement alternative pathway, participates in renal ischemia-reperfusion (IR) injury and also acts as a pattern-recognition molecule affecting apoptotic T-cell clearance. However, the role of properdin in tubular epithelial cells (TECs) at the repair phase post IR injury is not well defined. This study revealed that properdin knockout (P) mice exhibited greater injury in renal function and histology than wild-type (WT) mice post 72-h IR, with more apoptotic cells and macrophages in tubular lumina, increased active caspase-3 and HMGB1, but better histological structure at 24 h.

A comparison of the inflammatory response following autologous compared with allogenic islet cell transplantation.

Background: The initial response to islet transplantation and the subsequent acute inflammation is responsible for significant attrition of islets following both autologous and allogenic procedures. This multicentre study compares this inflammatory response using cytokine profiles and complement activation.

Methods: Inflammatory cytokine and complement pathway activity were examined in two cohorts of patients undergoing total pancreatectomy followed either by autologous (n=11) or allogenic (n=6) islet transplantation.

Prognostic Value of Complement Properdin in Cancer.

The complement system is readily triggered by the presence of damage-associated molecular patterns on the surface of tumor cells. The complement alternative pathway provides rapid amplification of the molecular stress signal, leading to complement cascade activation to deal with pathogens or malignant cells. Properdin is the only known positive regulator of the alternative pathway.

Properdin Is a Modulator of Tumour Immunity in a Syngeneic Mouse Melanoma Model.

: Tumours are often low immunogenic. The role of complement, an innate immune defence system, in tumour control has begun to be elucidated, but findings are conflicting. A role for properdin, an amplifier of complement activation, in tumour control has recently been implicated.

Dexamethasone acutely suppresses the anabolic SNAT2/SLC38A2 amino acid transporter protein in L6-G8C5 rat skeletal muscle cells.

Chronic metabolic acidosis plays a role in cachexia by enhancing total proteolysis in skeletal muscle. Glucocorticoid also triggers proteolysis and plays a permissive role in the effect of acidosis. The System A amino acid transporter SNAT2/SLC38A2 is ubiquitously expressed in mammalian cells including muscle, performing Na-dependent active import of neutral amino acids, and is strongly inhibited by low pH.

Complement Activation on Endothelial Cell-Derived Microparticles-A Key Determinant for Cardiovascular Risk in Patients with Systemic Lupus Erythematosus?

Systemic lupus erythematosus is a classical systemic autoimmune disease that overactivates complement and can affect all organs. Early diagnosis and effective management are important in this immune-complex-mediated chronic inflammatory disease, which has a strong component of vasculitis and carries an increased risk of thrombosis, even in the absence of antiphospholipid antibodies. Development of lupus nephritis can be life limiting but is managed with dialysis and renal transplantation.

Complement Properdin Regulates the Metabolo-Inflammatory Response to a High Fat Diet.

Overnutrition leads to a metabolic and inflammatory response that includes the activation of Complement. Properdin is the only amplifier of complement activation and increases the provision of complement activation products. Its absence has previously been shown to lead to increased obesity in mice on a high fat diet.

Complement Properdin Determines Disease Activity in MRL/ Mice.

In systemic lupus erythematosus, circulating immune complexes activate complement and, when trapped in renal capillaries, cause glomerulonephritis. Mouse models have been used in the preclinical assessment of targeting complement activation pathways to manage chronic inflammation in lupus. Properdin is the only known positive regulator of complement activation, but its role in the severity of lupus nephritis has not been studied yet.

The Value of Targeting Complement Components in Asthma.

Asthma is an important respiratory illness. Though pharmacological and biological treatment is well established and is staged according to endotypes and their responses to treatment, novel avenues are being explored. Our focus is complement.

Comparative Analysis of Risk Factors in Declined Kidneys from Donation after Brain Death and Circulatory Death.

Kidneys from donation after circulatory death (DCD) are more likely to be declined for transplantation compared with kidneys from donation after brain death (DBD). The aim of this study was to evaluate characteristics in the biopsies of human DCD and DBD kidneys that were declined for transplantation in order to rescue more DCD kidneys. Sixty kidney donors (DCD = 36, DBD = 24) were recruited into the study and assessed using donor demographics.

Pilot study: deficiency of mannose-binding lectin-dependent lectin pathway, a novel modulator in outcome from pancreatic islet auto-transplantation.

Background: Numerous factors influence pancreatic islet survival following auto-transplantation. Of these, the host immune response in the early peri-operative period is one of the most important. In this study we investigated the role of the mannose-binding lectin (MBL)-dependent pathway in a group of total pancreatectomy (TP) islet auto-transplantation (TPIAT) patients and classified them as competent or deficient in MBL activity.

An Appraisal on the Value of Using Nutraceutical Based Senolytics and Senostatics in Aging.

The average human life expectancy has increased globally, and continues to rise, owing to the substantive progress made in healthcare, medicine, sanitation, housing and education. This ultimately enriches society with a greater proportion of elderly people. Sustaining a healthy aged population is key to diminish the societal and economic impact of age-related infirmities.

Properdin: A Novel Target for Neuroprotection in Neonatal Hypoxic-Ischemic Brain Injury.

Hypoxic-ischemic (HI) encephalopathy is a major cause of neonatal mortality and morbidity, with a global incidence of 3 per 1,000 live births. Intrauterine or perinatal complications, including maternal infection, constitute a major risk for the development of neonatal HI brain damage. During HI, inflammatory response and oxidative stress occur, causing subsequent cell death.

Generation of Cytotoxic T Cells With Potential for Adoptive Tumor Immunotherapy of Multiple Myeloma.

Multiple myeloma is a life-threatening hematological malignancy, which is rarely curable by conventional therapies. Immunotherapy, using tumor antigen-specific, cytotoxic T-lymphocytes, may represent an alternative or additional treatment for multiple myeloma. In this study, we used hybrid cell lines, generated by fusion of an EBV B-lymphoblastoid cell line (B-LCL) and myeloma cells, to stimulate peripheral blood lymphocytes (PBLs) from patients with multiple myeloma.

Dietary Toll-Like Receptor Stimulants Promote Hepatic Inflammation and Impair Reverse Cholesterol Transport in Mice via Macrophage-Dependent Interleukin-1 Production.

The mechanisms connecting dietary intake of processed foods with systemic inflammatory markers and cardiovascular risk remain poorly defined. We sought to compare the abundance of pro-inflammatory stimulants of innate immune receptors in processed foods with those produced by the murine ileal and caecal microbiota, and to explore the impact of their ingestion on systemic inflammation and lipid metabolism . Calibrated receptor-dependent reporter assays revealed that many processed foods, particularly those based on minced meats, contain pro-inflammatory stimulants of Toll-like receptor (TLR)-2 and TLR4 at concentrations which greatly exceed those produced by the endogenous murine ileal microbiota.

Properdin binds independent of complement activation in an in vivo model of anti-glomerular basement membrane disease.

Properdin is the only known positive regulator of complement activation by stabilizing the alternative pathway convertase through C3 binding, thus prolonging its half-life. Recent in vitro studies suggest that properdin may act as a specific pattern recognition molecule. To better understand the role of properdin in vivo, we used an experimental model of acute anti-glomerular basement membrane disease with wild-type, C3- and properdin knockout mice.

Ex vivo modelling of the formation of inflammatory platelet-leucocyte aggregates and their adhesion on endothelial cells, an early event in sepsis.

Septicaemia is an acute inflammatory reaction in the bloodstream to the presence of pathogen-associated molecular patterns. Whole blood stimulation assays capture endotoxin-induced formation of aggregates between platelets and leucocytes using flow cytometry. We wanted to assess extent of spontaneous aggregate formation in whole blood stimulation assays and compare the effects of endotoxin and heat-killed, clinically relevant, bacterial pathogens on aggregate formation and then on adhesion of aggregates to TNFα-stimulated endothelial cells.

Role of Complement Properdin in Renal Ischemia-Reperfusion Injury.

Renal Ischemia-Reperfusion Injury (IRI) is one of the main causes of Acute Kidney Injury (AKI), and may lead to chronic kidney disease. The high mortality rate of AKI has not changed in the last 5 decades due to non-recognition, nephrotoxin exposure, delayed diagnosis and lack of specific intervention. Complement activation plays important roles in IRI-induced AKI because of its association with immunity, inflammation, cell death and tissue repair.

Vitamin D supplementation of a high fat high sugar diet ameliorates prediabetic phenotype in female LDLR and LDLR mice.

Introduction: Fatty liver disease is prevalent in populations with high caloric intake. Nutritherapeutic approaches are being considered, such as supplementary Vitamin D , to improve aspects of metabolic syndrome, namely fatty liver disease, hyperlipidemia, and insulin resistance associated with obesity.

Methods: We analyzed female LDLR and LDLR mice on a 10-week diabetogenic diet for markers of fatty liver disease, metabolic strain, and inflammation.

Resuscitation-promoting factors are important determinants of the pathophysiology in Mycobacterium tuberculosis infection.

Resuscitation promoting factors (Rpf) are peptidoglycan-hydrolyzing enzymes that are pivotal in the resuscitation of quiescent actinobacteria including Mycobacterium tuberculosis. From the published data, it is clear that Rpf are required for the resuscitation of non-replicating bacilli and pathogenesis in murine infection model of tuberculosis, although their direct influence on human Mycobacterium tuberculosis infection is ill-defined. In this review, we describe the progress in the understanding of the roles that Rpf play in human tuberculosis pathogenesis and importance of bacilli dependent upon Rpf for growth for the outcome of human tuberculosis.

Functional and structural insight into properdin control of complement alternative pathway amplification.

Properdin (FP) is an essential positive regulator of the complement alternative pathway (AP) providing stabilization of the C3 and C5 convertases, but its oligomeric nature challenges structural analysis. We describe here a novel FP deficiency (E244K) caused by a single point mutation which results in a very low level of AP activity. Recombinant FP E244K is monomeric, fails to support bacteriolysis, and binds weakly to C3 products.

Tumour cell conditioned medium reveals greater M2 skewing of macrophages in the absence of properdin.

Introduction: The tumour microenvironment is shaped by the interaction of immune, non immune, and tumour cells present in close proximity. Tumour cells direct the development of a locally immune suppressed state, affecting the activity of anti tumour T cells and preparing the escape phase of tumour development. Macrophages in the tumour typically develop into so-called tumour associated macrophages with a distinct profile of activities which lead to a reduction in inflammation and antigen presentation.

In vitro Modulation of the LPS-Induced Proinflammatory Profile of Hepatocytes and Macrophages- Approaches for Intervention in Obesity?

Low grade endotoxemia is a feature of obesity which is linked to development of steatohepatitis in non-alcoholic fatty liver disease. In this study, macrophages (J774) and hepatocytes (HepG2) were stimulated with lipopolysaccharide (LPS) from E. coli 0111: B4 and analyzed for modulation of this response when preconditioned or stimulated subsequent to LPS, with different doses of Vitamin D3 or docosahexaenoic acid (DHA) over a time period of 1 and 5 days.

Experimentally-induced anti-myeloperoxidase vasculitis does not require properdin, MASP-2 or bone marrow-derived C5.

Anti-neutrophil cytoplasmic antibody vasculitis is a systemic autoimmune disease with glomerulonephritis and pulmonary haemorrhage as major clinical manifestations. The name reflects the presence of autoantibodies to myeloperoxidase and proteinase-3, which bind to both neutrophils and monocytes. Evidence of the pathogenicity of these autoantibodies is provided by the observation that injection of anti-myeloperoxidase antibodies into mice causes a pauci-immune focal segmental necrotizing glomerulonephritis which is histologically similar to the changes seen on renal biopsy in patients.