The N-terminal shuttle domain of Erv1 determines the affinity for Mia40 and mediates electron transfer to the catalytic Erv1 core in yeast mitochondria

Erv1 and Mia40 constitute the two important components of the disulfide relay system that mediates oxidative protein folding in the mitochondrial intermembrane space. Mia40 is the import receptor that recognizes the substrates introducing disulfide bonds while it is reduced. A key function of Erv1 is to recycle Mia40 to its active oxidative state. Our aims here were to dissect the domain of Erv1 that mediates the protein–protein interaction with Mia40 and to investigate the interactions between the shuttle domain of Erv1 and its catalytic core and their relevance for the interaction with Mia40. We purified these domains separately as well as cysteine mutants in the shuttle and the active core domains. The noncovalent interaction of Mia40 with Erv1 was measured by isothermal titration calorimetry, whereas their covalent mixed disulfide intermediate was analyzed in reconstitution experiments in vitro and in organello. We established that the N-terminal shuttle domain of Erv1 is necessary and sufficient for interaction to occur. Furthermore, we provide direct evidence for the intramolecular electron transfer from the shuttle cysteine pair of Erv1 to the core domain. Finally, we reconstituted the system by adding in trans the N- and C- terminal domains of Erv1 together with its substrate Mia40

Pauci-Immune Vasculitides with Kidney Involvement

The clinical entity of pauci-immune vasculitis encompasses a group of diseases that may involve any organ system of the body and may be fatal if left untreated. This chapter will review these diseases, with a special interest in the clinical setting of kidney involvement. Small vessel vasculitides associated with the presence of antineutrophil cytoplasmic autoantibodies in the circulation will be the main part, since the vast majority of patients with histopathological proof of pauci-immune vasculitis are positive for these antibodies. Pauci-immune glomerulonephritis often manifests with rapidly deteriorating kidney function, while it may be accompanied by systemic necrotizing small vessel vasculitis such as microscopic polyangiitis, granulomatosis with polyangiitis, or eosinophilic granulomatosis with polyangiitis. Importantly, antineutrophil cytoplasmic autoantibody specificity has been shown to be associated with distinct clinical syndromes and different prognostic profiles among patients with pauci-immune vasculitis allowing easier recognition of the disease and long-term prognosis. Each of the clinical phenotypes will be described thoroughly with respect to the criteria required for establishment of diagnosis, the specific characteristics of renal and extrarenal histopathology, the clinical picture, the therapeutic management, and prognosis in short and long terms

Immune Complex Small-Vessel Vasculitis with Kidney Involvement

The term immune complex small-vessel vasculitis encompasses anti-glomerular basement membrane disease, cryoglobulinemic vasculitis, IgA vasculitis and hypocomplementemic urticarial vasculitis. These disorders affect predominantly small vessels, and renal involvement is frequent. In this chapter, we shall discuss thoroughly anti-GBM disease, cryoglobulinemic and IgA vasculitis with respect to the criteria required for the establishment of diagnosis, the specific characteristics of renal histopathology, the clinical picture, prognosis, and therapeutic management

Editorial: Pathogenesis and management of glomerular diseases

Glomerular diseases are considered to be the result of inherited or acquired disorders and may manifest in a variety of clinical syndromes, including numerous pictures in terms of severity. A significant number of patients have no symptoms while others discover urinary abnormalities in routine screenings or they may experience low grade symptoms, such as macroscopic hematuria and edema in the lower extremities. Occasional patients present with rapidly progressive glomerulonephritis, a serious condition which may end up in advanced or end-stage kidney disease if remain untreated. Renal histopathology evaluation in combination with the characteristics of the clinical syndrome remains the cornerstone for accurate diagnosis and evidence-based treatment. During the past decade substantial progress has been made in this field, especially regarding the etiology and pathogenesis of these diseases. Recent knowledge has been added, including molecular mechanisms, genetic associations and immunologically-mediated forms of glomerulonephritis, underlining the autoimmune basis associated with genetic risk factors and environmental stimulus leading to immune-mediated injury of the glomeruli

Lupus Nephritis: Clinical Picture, Histopathological Diagnosis, and Management

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that can affect almost every organ of the body and presents with a great variety of clinical features. SLE effect on kidneys, mostly referred to as lupus nephritis, is of special interest for the rheumatologist and nephrologist for three reasons. First, lupus nephritis is one of the commonest types of organ involvement in this disorder, affecting as up to 45% of all patients with SLE. Second, it presents with a great variety of clinical and histopathological findings, and thus, therapy must be tailored accordingly. Third, it greatly affects the morbidity and mortality of SLE patients. Taking these facts into account, this chapter is centered on lupus nephritis from the perspective of the clinical nephrologist and renal pathologist. This chapter elaborates the diversity of clinical features of lupus nephritis, in relation to the different histopathological forms of the disease and the therapeutic options that are available to date, as well as the pathogenesis, natural history, and prognosis of patients with lupus nephritis

Incidence and Clinical Significance of De Novo

Kidney transplantation has evolved over more than half a century and remarkable progress has been made in patient and graft outcomes. Despite these advances, chronic allograft dysfunction remains a major problem. Among other reasons, de novo formation of antibodies against donor human leukocyte antigens has been recognized as one of the major risk factors for reduced allograft survival. The type of treatment in the presence of donor specific antibodies (DSA) posttransplantation is largely related to the clinical syndrome the patient presents with at the time of detection. There is no consensus regarding the treatment of stable renal transplant recipients with circulating de novo DSA. On the contrast, in acute or chronic allograft dysfunction transplant centers use various protocols in order to reduce the amount of circulating DSA and achieve long-term graft survival. These protocols include removal of the antibodies by plasmapheresis, intravenous administration of immunoglobulin, or depletion of B cells with anti-CD20 monoclonal antibodies along with tacrolimus and mycophenolate mofetil. This review aims at the comprehension of the clinical correlations of de novo DSA in kidney transplant recipients, assessment of their prognostic value, and providing insights into the management of these patients

Mitophagy and the therapeutic clearance of damaged mitochondria for neuroprotection

Mitochondria are the foremost producers of the cellular energy currency ATP. They are also a significant source of reactive oxygen species and an important buffer of intracellular calcium. Mitochondrial retrograde signals regulate energy homeostasis and pro-survival elements whereas anterograde stimuli can trigger programmed cell death. Maintenance of a healthy, functional mitochondria network is therefore essential, and several mechanisms of mitochondrial quality control have been described. Mitochondrial dysfunction is linked to several neurodegenerative conditions including Parkinson, and Huntingdon diseases as well as Amyotrophic lateral sclerosis. Understanding the mechanisms governing mitochondrial quality control may reveal novel strategies for pharmacological intervention and disease therapy

Artificial selection for increased dispersal results in lower fitness

Dispersal often covaries with other traits, and this covariation was shown to have a genetic basis. Here, we wanted to explore to what extent genetic constraints and correlational selection can explain patterns of covariation between dispersal and key life-history traits-lifespan and reproduction. A prediction from the fitness-associated dispersal hypothesis was that lower genetic quality is associated with higher dispersal propensity as driven by the benefits of genetic mixing. We wanted to contrast it with a prediction from a different model that individuals putting more emphasis on current rather than future reproduction disperse more, as they are expected to be more risk-prone and exploratory. However, if dispersal has inherent costs, this will also result in a negative genetic correlation between higher rates of dispersal and some aspects of performance. To explore this issue, we used the dioecious nematode Caenorhabditis remanei and selected for increased and decreased dispersal propensity for 10 generations, followed by five generations of relaxed selection. Dispersal propensity responded to selection, and females from high-dispersal lines dispersed more than females from low-dispersal lines. Females selected for increased dispersal propensity produced fewer offspring and were more likely to die from matricide, which is associated with a low physiological condition in Caenorhabditis nematodes. There was no evidence for differences in age-specific reproductive effort between high- and low-dispersal females. Rather, reproductive output of high-dispersal females was consistently reduced. We argue that our data provide support for the fitness-associated dispersal hypothesis

Impact of pre-transplant time on dialysis on survival in patients with lupus nephritis

Lupus nephritis (LN) is an important cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE) often leading to end-stage renal failure (ESRF) and necessitating renal transplantation (rTp). Optimal timing of rTp in SLE patients with ESRF is uncertain and could potentially affect survival. We investigated the time spent on dialysis before rTp and survival following rTp in a cohort of SLE patients. Retrospective analysis of all adult SLE patients receiving rTp over a 40-year period (1975–2015) in two tertiary UK centres. Cox proportional hazard regression and receiver operator curves (ROC) were used to determine the risk associated with time on dialysis before rTp and other potential predictors. Forty patients (age 35 ± 11 years, 34 female, 15 Caucasian, 15 Afro–Caribbean and 10 South Asian) underwent rTp. During a median follow-up of 104 months (IQR 80,145), eight (20%) patients died and the 5-year survival was 95%. Univariate analysis identified time on dialysis prior to rTp as the only potentially modifiable risk predictor of survival with a hazard ratio of 1.013 for each additional month spent on dialysis (95% CI = 1.001–1.026, p = 0.03). ROC curves demonstrated that > 24 months on dialysis had an adverse effect with sensitivity of 0.875 and specificity 0.500 for death. No other modifiable predictors were significantly associated with mortality, indicating that time on dialysis had an independent effect. Increased time on dialysis pre-transplantation is an independent modifiable risk factor of mortality in this cohort of patients with lupus nephritis