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BackgroundFibroblast growth factor 23 (FGF23), a phosphate-regulating hormone that increases early in the course of chronic kidney disease (CKD), is associated with disease progression in patients with established CKD. Here we aimed to investigate the association between plasma FGF23 and new-onset CKD in the general population.MethodsWe included 5253 individuals without CKD who participated in the Prevention of Renal and Vascular Endstage Disease study, a prospective, population-based cohort. Multi-variable Cox regression was used to study the association of plasma C-terminal FGF23 with new-onset CKD, defined as a combined endpoint of estimated glomerular filtration rate (eGFR) 30 mg/24 h or both, or with all-cause mortality.ResultsThe median baseline FGF23 was 68 [interquartile range (IQR) 56–85] RU/mL, eGFR was 95 ± 13 mL/min/1.73 m2 and UAE was 7.8 (IQR 5.8–11.5) mg/24 h. After follow-up of 7.5 (IQR 7.2–8.0) years, 586 participants developed CKD and 214 participants died. A higher FGF23 level was associated with new-onset CKD, independent of risk factors for kidney disease and parameters of bone and mineral homoeostasis {fully adjusted hazard ratio (HR) 1.25 [95% confidence interval (CI) 1.10–1.44] per doubling of FGF23; P = 0.001}. In secondary analyses, FGF23 was independently associated with new-onset eGFR 30 mg/24 h [adjusted HR 1.24 (95% CI 1.06–1.45); P = 0.01] individually. A higher FGF23 level was also associated with an increased risk of all-cause mortality [fully adjusted HR 1.30 (95% CI 1.03–1.63); P = 0.03].ConclusionsHigh FGF23 levels are associated with an increased risk of new-onset CKD and all-cause mortality in this prospective population-based cohort, independent of established CKD risk factors.

BACKGROUND: Arterial stiffness influences the contour of the digital pressure pulse wave. METHOD: Here, we investigated whether the digital pulse propagation index (DPPI), based on the digital pressure pulse wave, DPPI is associated with cardiovascular events, heart failure, and mortality in a large population-based cohort. Between 2001 and 2003, DPPI was measured with a PortaPres noninvasive hemodynamic monitoring device (FinaPres Medical Systems, Amsterdam, The Netherlands) in participants of the Prevention of Renal and Vascular End-stage Disease study, a community-based cohort. We assessed the main determinants of the DPPI and investigated associations of DPPI with cardiovascular events and mortality. RESULTS: The study included 5474 individuals. Mean age was 52.3 ± 11.8 years and 50.5% was male. Median baseline DPPI was 5.81 m/s (interquartile range 5.47-6.20). Higher age, mean arterial blood pressure, body height, heart rate, current smoking, and lower HDL cholesterol levels and waist circumference were independent determinants of the DPPI (r = 0.43). After adjustment for heart rate, highlogDPPI was associated with all-cause mortality [hazard ratio: 1.67, 95% confidence interval (1.55-1.81) per SD; P

Contains fulltext : 215593.pdf (Publisher’s version ) (Closed access) Although blood pressure control is a major goal in chronic kidney disease, no worldwide overview of either its achievement or antihypertensive prescriptions is currently available. To evaluate this we compared crude prevalence of uncontrolled blood pressure among 17 cohort studies, including 34 602 individuals with estimated glomerular filtration rate under 60 ml/min/1.73 m(2) and treated hypertension across four continents, and estimated observed to expected prevalence ratios, adjusted for potential confounders. Crude prevalence of blood pressure of 140/90 mm Hg or more varied from 28% to 61% and of blood pressure of 130/80 or more from 54% to 84%. Adjusted prevalence ratios indicated poorer hypertension control than expected in cohorts from European countries, India, and Uruguay, and better control in patients from North American and high-income Asian countries. Four antihypertensive drug classes or more were prescribed to more than 30% of participants in North American and some European cohorts, but this practice was less common elsewhere. Renin angiotensin-aldosterone system inhibitors were the most common antihypertensive drugs, prescribed for 54% to 91% of cohort participants. Differences for other drug classes were much stronger, ranging from 11% to 79% for diuretics, 22% to 70% for beta-blockers, and 27% to 75% for calcium-channel blockers. The confounders studied explain only a part of the international variation in blood pressure control among individuals with chronic kidney disease. Thus, considerable heterogeneity in prescription patterns worldwide calls for further investigation into the impact of different approaches on patient outcomes.

The toxins that some bacteria secrete to kill off rival species can also generate mutations that help toxin-resistant populations adapt to new environments.

Gasdermin B (GSDMB) belongs to a large family of pore forming cytolysins that execute inflammatory cell death programs. While genetic studies have linked GSDMB polymorphisms to human disease, its function in the immunological response to pathogens remains poorly understood. Here, we report a dynamic host-pathogen conflict between GSDMB and the IpaH7.8 effector protein secreted by enteroinvasive Shigella flexneri. We show that IpaH7.8 ubiquitinates and targets GSDMB for 26S proteasome destruction. This virulence strategy protects Shigella from the bacteriocidic activity of Natural Killer cells by suppressing Granzyme-A mediated activation of GSDMB. In contrast to the canonical function of most Gasdermin-family members, GSDMB does not inhibit Shigella by lysing host cells. Rather, it exhibits direct microbiocidal activity through recognition of phospholipids found on Gram-negative bacterial membranes. These findings place GSDMB as a central executioner of intracellular bacterial killing and reveals a mechanism employed by pathogens to counteract this host defense system.

BackgroundErythropoietin (EPO) has been reported as a novel determinant of fibroblast growth factor 23 (FGF23) production; however, it is unknown whether FGF23 is stimulated by chronic exposure to EPO or by EPO administration in nonpolycystic chronic kidney disease (CKD) models.MethodsWe analyzed the effects of chronic EPO on FGF23 in murine models with chronically high EPO levels and normal kidney function. We studied the effects of exogenous EPO on FGF23 in wild-type mice, with and without CKD, injected with EPO. Also, in four independent human CKD cohorts, we evaluated associations between FGF23 and serum EPO levels or exogenous EPO dose.ResultsMice with high endogenous EPO have elevated circulating total FGF23, increased disproportionately to intact FGF23, suggesting coupling of increased FGF23 production with increased proteolytic cleavage. Similarly, in wild-type mice with and without CKD, a single exogenous EPO dose acutely increases circulating total FGF23 out of proportion to intact FGF23. In these murine models, the bone marrow is shown to be a novel source of EPO-stimulated FGF23 production. In humans, serum EPO levels and recombinant human EPO dose are positively and independently associated with total FGF23 levels across the spectrum of CKD and after kidney transplantation. In our largest cohort of 680 renal transplant recipients, serum EPO levels are associated with total FGF23, but not intact FGF23, consistent with the effects of EPO on FGF23 production and metabolism observed in our murine models.ConclusionEPO affects FGF23 production and metabolism, which may have important implications for CKD patients.

Contains fulltext : 173022.pdf (Publisher’s version ) (Closed access) Background.: Blockade of the renin-angiotensin-aldosterone system (RAAS) retards progression of chronic kidney disease. Yet, in many patients, the renoprotective effect is incomplete. A high circulating level of the phosphaturic hormone fibroblast growth factor 23 is associated with an impaired response to RAAS blockade-based therapy in clinical studies. Therefore, we addressed whether administration of recombinant fibroblast growth factor 23 (FGF23) interferes with the efficacy of angiotensin receptor blocker (ARB) treatment in a mouse model of renal fibrosis [unilateral ureteral obstruction (UUO)]. Methods.: UUO mice were treated with losartan (100 mg/L in drinking water), recombinant FGF23 (160 ng/kg i.p. twice daily), their combination or vehicle ( n = 10 per group). Seven days after the UUO procedure, kidney tissue was analyzed for markers of RAAS activity, inflammation and fibrosis using real-time PCR and immunohistochemistry. Results.: In the contralateral (non-affected) kidneys of ARB-treated UUO mice, administration of FGF23 reversed the induction of renin, ACE, ACE2 and AT1 receptor mRNA expression, suggesting interference with the physiological response to RAAS blockade by FGF23. Furthermore, recombinant FGF23 infusion prevented ARB-induced klotho upregulation in contralateral kidneys. In the UUO kidneys, klotho was majorly reduced in all groups. Pro-inflammatory gene expression (MCP-1, TNF-alpha) induced in UUO kidneys was reduced by ARB treatment; this anti-inflammatory effect was reversed by FGF23. In contrast, ARB-induced reduction of (pre-)fibrotic gene expression was not reversed by FGF23. Conclusions.: Our findings show pharmacological interaction between exogenous FGF23 and losartan, thus serving as a proof of principle for crosstalk between the FGF23-klotho axis and RAAS.

Elevated levels of erythropoietin (EPO) are associated with an increased risk of death in renal transplant recipients (RTRs), but the underlying mechanisms remain unclear. Emerging data suggest that EPO stimulates production of the phosphaturic hormone fibroblast growth factor 23 (FGF23), another strong risk factor for death in RTRs. We hypothesized that the hitherto unexplained association between EPO levels and adverse outcomes may be attributable to increased levels of FGF23. We included 579 RTRs (age 51 &plusmn, 12 years, 55% males) from the TransplantLines Insulin Resistance and Inflammation Cohort study (NCT03272854). During a follow-up of 7.0 years, 121 RTRs died, of which 62 were due to cardiovascular cause. In multivariable Cox regression analysis, EPO was independently associated with all-cause (HR, 1.66, 95% CI 1.16&ndash, 2.36, P = 0.005) and cardiovascular death (HR, 1.87, 95% CI 1.14&ndash, 3.06, P = 0.01). However, the associations were abrogated following adjustment for FGF23 (HR, 1.28, 95% CI 0.87&ndash, 1.88, P = 0.20, and HR, 1.45, 95% CI 0.84&ndash, 2.48, P = 0.18, respectively). In subsequent mediation analysis, FGF23 mediated 72% and 50% of the association between EPO and all-cause and cardiovascular death, respectively. Our results underline the strong relationship between EPO and FGF23 physiology, and provide a potential mechanism underlying the relationship between increased EPO levels and adverse outcomes in RTRs.

BACKGROUND AND OBJECTIVES: The sodium glucose cotransporter 2 (SGLT-2) inhibitor dapagliflozin is a novel drug for the treatment of diabetes mellitus. Recent studies suggest that SGLT-2 inhibitors affect phosphate homeostasis, but their effects on phosphate-regulating hormones in patients with diabetic kidney disease are still unclear.DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a post-hoc analysis of a double-blind, randomized, crossover trial in patients with type 2 diabetes with early-stage diabetic kidney disease on stable renin-angiotensin-aldosterone system blockade, with an albumin-to-creatinine ratio between 100 and 3500 mg/g, eGFR≥45 ml/min per 1.73 m2, and glycosylated hemoglobin≥7.2% and RESULTS: Thirty-one patients (age 62 years; 23% female) were analyzed. Compared with placebo, dapagliflozin increased serum phosphate by 9% (95% confidence interval, 4% to 15%; P=0.002), PTH increased by 16% (3% to 30%; P=0.01), FGF23 increased by 19% (0.3% to 42%; P=0.05), and serum 1,25(OH)2D decreased by -12% (-25% to 4%; P=0.12). Calcium and 25(OH)D were unaffected. We found no correlation between changes in markers of phosphate homeostasis and changes in eGFR or 24-hour albumin excretion during dapagliflozin treatment.CONCLUSIONS: Dapagliflozin increases serum phosphate, plasma PTH, and FGF23. This effect was independent of concomitant changes in eGFR or 24-hour albumin excretion.

The enteric attaching and effacing (A/E) pathogens enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) and the invasive pathogens enteroinvasive E. coli (EIEC) and Shigella encode type III secretion systems (T3SS) used to inject effector proteins into human host cells during infection. Among these are a group of effectors required for NF-κB-mediated host immune evasion. Recent studies have identified several effector proteins from A/E pathogens and EIEC/ Shigella that are involved in suppression of NF-κB and have uncovered their cellular and molecular functions. A novel mechanism among these effectors from both groups of pathogens is to coordinate effector function during infection. This cooperativity among effector proteins explains how bacterial pathogens are able to effectively suppress innate immune defense mechanisms in response to diverse classes of immune receptor signaling complexes (RSCs) stimulated during infection.

Background: Increased levels of phosphate and fibroblast growth factor-23 (FGF23) are strong predictors of cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). Preliminary data suggest that interventions lowering gastro-intestinal phosphate uptake lowers serum FGF23 concentrations and improves cardiovascular risk and subsequently survival. However, data are lacking about the magnitude of effects, the effect in different stages of CKD and whether there is a dose-effect relationship. Methods: Therefore, the Sevelamer on FGF23 Trial (SoFT) is designed as an open-label, single-arm, clinical pilot study aiming to demonstrate the feasibility of a phosphate-restricted diet in combination with the phosphate binder sevelamer to induce an effective, predictable and sustained decrease in FGF23 level in patients with an estimated glomerular filtration rate (eGFR) of 15-90 or >90 ml/min/1.73 m2 with proteinuria >1.0 g in 24 h urine collection, despite optimally dosed RAAS blockade, without inducing hypophosphatemia using a forced uptitration treatment regimen aimed at restricting phosphate uptake.

Reduction of residual albuminuria during single-agent renin-angiotensin-aldosterone blockade is accompanied by improved cardiorenal outcomes in CKD. We studied the individual and combined effects of the vitamin D receptor activator paricalcitol (PARI) and dietary sodium restriction on residual albuminuria in CKD. In a multicenter, randomized, placebo (PLAC)-controlled, crossover trial, 45 patients with nondiabetic CKD stages 1-3 and albuminuria >300 mg/24 h despite ramipril at 10 mg/d and BP

The comorbidity of schizophrenia and idiopathic Parkinson's disease (IPD) is illustrated by a case description of a schizophrenic patient who develops motor symptoms finally diagnosed and treated as comorbid IPD. Several aspects of the clinical challenges of this comorbidity are discussed and an overview of earlier reported cases is presented. IPD must be distinguished from neuroleptic-induced parkinsonism by clinical course and characteristics. A SPECT scan is helpful for diagnosis. We recommend antiparkinsonian treatment to be prescribed only with the protection of antipsy- chotic agents, of which clozapine and quetiapine are the best choices. Abstract Introduction According to the dopamine hypothesis of schizophre- nia, its positive symptoms (such as delusions and halluci- nations) arise from increased dopamine activity (1, 2). In contrast, hypodopaminergic transmission is the underlying mechanism of idiopathic Parkinson's disease (IPD). Sev- eral patients with both schizophrenia and IPD have been described (3-12). The apparent paradox of the co-existence of schizophrenia (hyperdopaminergic) and IPD (hypodopa- minergic) can probably be explained by dopaminergic neu- rons projecting to the motor striatum, and those projecting to association regions being affected independently (10): in IPD, degeneration occurs primarily in midbrain dopaminer- gic neurons, whereas dopaminergic neurons in other brain regions are less vulnerable to degeneration (13). It is less clear why so few patients with both conditions have been described. Millions of individuals exist with either schizo- phrenia or IPD and yet there are only a handful of reported cases of the co-existence. Apart from these theoretical aspects, in clinical practice the combination of schizophrenia and IPD in one individual presents a challenge to clinicians. First, when confronted with a schizophrenic patient displaying a movement disor- der resembling IPD, clinicians have to differentiate between neuroleptic-induced parkinsonism (NIP) and IPD. Second, when schizophrenia and IPD are eventually co-diagnosed, clinicians have to find a balance in the pharmacotherapy of the two disorders: antipsychotics block dopaminergic neu- rotransmission, thereby increasing the symptoms of IPD, whereas antiparkinsonian drugs can exacerbate psycho- sis by enhancing dopaminergic neurotransmission. In this article we present a case report of comorbid schizophrenia and IPD. The clinical implications are discussed and a con - cise review of other reported cases also in comparison to our case is presented.

The linear ubiquitin chain assembly complex (LUBAC) is a multimeric E3 ligase that catalyses M1 or linear ubiquitination of activated immune receptor signalling complexes (RSCs). Mutations that disrupt linear ubiquitin assembly lead to complex disease pathologies including immunodeficiency and autoinflammation in both humans and mice, but microbial toxins that target LUBAC function have not yet been discovered. Here, we report the identification of two homologous Shigella flexneri type III secretion system effector E3 ligases IpaH1.4 and IpaH2.5, which directly interact with LUBAC subunit Heme-oxidized IRP2 ubiquitin ligase-1 (HOIL-1L) and conjugate K48-linked ubiquitin chains to the catalytic RING-between-RING domain of HOIL-1-interacting protein (HOIP). Proteasomal degradation of HOIP leads to irreversible inactivation of linear ubiquitination and blunting of NF-κB nuclear translocation in response to tumour-necrosis factor (TNF), IL-1β and pathogen-associated molecular patterns. Loss of function studies in mammallian cells in combination with bacterial genetics explains how Shigella evades a broad spectrum of immune surveillance systems by cooperative inhibition of receptor ubiquitination and reveals the critical importance of LUBAC in host defence against pathogens.

Endoplasmic reticulum (ER) stress is a major contributor to inflammatory diseases, such as Crohn’s disease and type 2 diabetes1,2. ER stress induces the unfolded protein response (UPR), which involves activation of three transmembrane receptors, ATF6 (activating transcription factor 6), PERK (protein kinase RNA-like endoplasmic reticulum kinase) and IRE1α (inositol-requiring enzyme 1α)3 (Extended Data figure 1a). Once activated, IRE1α recruits TRAF2 (TNF receptor-associated factor 2) to the ER membrane to initiate inflammatory responses via the nuclear factor kappa B (NF-κB) pathway4. Inflammation is commonly triggered when pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) or nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), detect tissue damage or microbial infection. However, it is not clear which PRRs play a major role in inducing inflammation during ER stress. Here we show that NOD1 and NOD2, two members of the NLR family of PRRs, are important mediators of ER stress-induced inflammation. The ER stress inducers thapsigargin and dithiothreitol (DTT) triggered production of the pro-inflammatory cytokine interleukin (IL)-6 in a NOD1/2-dependent fashion. Inflammation and IL-6 production triggered by infection with Brucella abortus, which induces ER stress by injecting the type IV secretion system (T4SS) effector protein VceC into host cells5, was TRAF2, NOD1/2 and RIP2-dependent and could be blunted by treatment with the ER-stress inhibitor tauroursodeoxycholate (TUDCA) or an IRE1α kinase inhibitor. The association of NOD1 and NOD2 with pro-inflammatory responses induced by the IRE1α/TRAF2 signaling pathway provides a novel link between innate immunity and ER stress-induced inflammation.

Brucellosis is a global disease of domestic and wild mammals that is caused by intracellular bacteria of the genus Brucella. Although humans are not a natural reservoir for Brucella, infection in the human population is common in many countries, and brucellosis is one of the most common zoonotic infections. Brucella species have evolved to avoid the host’s immune system and infection is usually characterized by long-term persistence of the bacteria. One important Brucella virulence factor for intracellular survival and persistence in the host is the type IV secretion system. This review will discuss the Brucella type IV secretion system in detail, including current knowledge of architecture and regulation, as well as the newly identified effector substrates that this system transports into host cells.

In humans, pathogenic Brucella species cause a febrile illness known as brucellosis. A key pathogenic trait of this group of organisms is their ability to survive in immune cells and persist in tissues of the reticuloendothelial system, a process that requires the function of a Type IV secretion system. In contrast to other well-studied Gram-negative bacteria, Brucella spp. do not cause inflammation at the site of invasion, but have a latency period of 2-4 weeks before the onset of symptoms. This review discusses several mechanisms that allow Brucella spp. both to evade detection by pattern recognition receptors of the innate immune system and suppress their signalling. In contrast to these stealth features, the VirB Type IV secretion system, which mediates survival within phagocytic cells, stimulates innate immune responses in vivo. The responses stimulated by this virulence factor are sufficient to check bacterial growth, but not to elicit sterilizing immunity. The result is a stand-off between host and pathogen that results in persistent infection.

Survival and replication inside host cells by Brucella spp. requires a type IV secretion system (T4SS), encoded by the virB locus. However, the identity of the molecules secreted by the T4SS has remained elusive. We hypothesized that proteins translocated by the T4SS would be co-regulated with the virB operon. The LuxR family regulator VjbR, known to regulate virB, bound a fragment of the virB promoter containing an 18 bp palindromic motif (virB promoter box), showing that VjbR regulated the virB operon directly. To identify virB co-regulated genes, we searched the Brucella suis 1330 and B. abortus 2308 genomes for genes with an upstream virB promoter box. One hundred and forty-four promoters in the two genomes contained the virB promoter box, including those of fliC encoding flagellin and cgs encoding cyclic beta-glucan synthetase. Thirteen of these proteins were tested for VirB-dependent translocation into macrophages using a beta-lactamase reporter assay. This analysis resulted in the identification of the proteins encoded by BAB1_1652 (VceA) and BR1038/BAB1_1058 (VceC) as novel protein substrates of the Brucella T4SS. VceC could also be translocated by the Legionella pneumophila Dot/Icm T4SS into host cells. Our results suggest that VjbR co-ordinates expression of the T4SS and at least two of its secreted substrates.

Peptide receptor-targeted radionuclide therapy is nowadays being performed with radiolabeled DOTA-conjugated peptides, such as [90Y-DOTA0,Tyr3]octreotide (also known as OctreoTher or 90Y-DOTATOC). The incorporation of 90Y3+ is typically > or = 99%, however, since a total patient dose can be as high as 26 GBq or 700 mCi the amount of free 90Y3+ (= non-DOTA-incorporated) can be substantial. Free 90Y3+ accumulates in bone with undesired radiation of bone marrow as a consequence. 90Y-DTPA is excreted rapidly via the kidneys. Incorporation of free 90Y3+ into 90Y-DTPA might prevent this fraction from being accumulated into bone, therefore we have investigated: the biodistribution in rats of 90YCl3, [90Y-DOTA0,Tyr3]octreotide, and 90Y-DTPA; possibilities to complex 10% of free 90Y3+ in a [90Y-DOTA0,Tyr3]octreotide containing solution into 90Y-DTPA prior to intravenous injection; and effects of 10% free 90Y3+ in [90Y-DOTA0,Tyr3]octreotide solution, in the presence and in the absence of excess DTPA, on the biodistribution of in rats. The following results are presented: 90YCl3 showed high skeletal uptake (i.e., 1% ID (injected dose) per gram femur, with main localization in the epiphyseal plates) and a 24 h total body retention of 74% ID; 90Y-DTPA had rapid renal clearance, and 24 h total body retention of < 5% ID; added free 90Y3+ in [90Y-DOTA0,Tyr3]octreotide solution could rapidly be incorporated into 90Y-DTPA at room temperature; and accumulation of 90Y3+ in femur, blood, and liver was related to the amount of free 90Y3+, whereas these accumulations could be prevented by the addition of DTPA. In conclusion, the addition of excess DTPA to [90Y-DOTA0,Tyr3]octreotide with incomplete 90Y-incorporation is recommended.

Optimal albuminuria reduction is considered essential to halting chronic kidney disease (CKD) progression. Both vitamin D receptor activator (VDRA) treatment and dietary sodium restriction potentiate the efficacy of renin-angiotensin-aldosterone-system (RAAS) blockade to reduce albuminuria. The ViRTUE study addresses whether a VDRA in combination with dietary sodium restriction provides further albuminuria reduction in non-diabetic CKD patients on top of RAAS blockade. The ViRTUE study is an investigator-initiated, prospective, multi-centre, randomized, double-blind (paricalcitol versus placebo), placebo-controlled trial targeting stage 1-3 CKD patients with residual albuminuria of300 mg/day due to non-diabetic glomerular disease, despite angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use. During run-in, all subjects switched to standardized RAAS blockade (ramipril 10 mg/day) and blood pressure titrated to140/90 mmHg according to a standardized protocol. Eligible patients are subsequently enrolled and undergo four consecutive study periods in random order of 8 weeks each: (i) paricalcitol (2 µg/day) combined with a liberal sodium diet (∼200 mmol Na(+)/day, i.e. mean sodium intake in the general population), (ii) paricalcitol (2 µg/day) combined with dietary sodium restriction (target: 50 mmol Na(+)/day), (iii) placebo combined with a liberal sodium diet and (iv) placebo combined with dietary sodium restriction. Data are collected at the end of each study period. The primary outcome is 24-h urinary albumin excretion. Secondary study outcomes are blood pressure, renal function (estimated glomerular filtration rate), plasma renin activity and, in a sub-population (N = 9), renal haemodynamics (measured glomerular filtration rate and effective renal plasma flow). A sample size of 50 patients provides 90% power to detect a 23% reduction in albuminuria, assuming a 25% dropout rate. Further reduction of residual albuminuria by combination of VDRA treatment and sodium restriction during single-agent RAAS-blockade will justify long-term studies on cardiorenal outcomes and safety.NTR2898 (Dutch trial register).

Pathogenic bacteria introduce effector proteins directly into the cytosol of eukaryotic cells to promote invasion and colonization. OspG, a Shigella spp. effector kinase, plays a role in this process by helping to suppress the host inflammatory response. OspG has been reported to bind host E2 ubiquitin-conjugating enzymes activated with ubiquitin (E2∼Ub), a key enzyme complex in ubiquitin transfer pathways. A co-crystal structure of the OspG/UbcH5c∼Ub complex reveals that complex formation has important ramifications for the activity of both OspG and the UbcH5c∼Ub conjugate. OspG is a minimal kinase domain containing only essential elements required for catalysis. UbcH5c∼Ub binding stabilizes an active conformation of the kinase, greatly enhancing OspG kinase activity. In contrast, interaction with OspG stabilizes an extended, less reactive form of UbcH5c∼Ub. Recognizing conserved E2 features, OspG can interact with at least ten distinct human E2s∼Ub. Mouse oral infection studies indicate that E2∼Ub conjugates act as novel regulators of OspG effector kinase function in eukaryotic host cells.

For the seaward harbour extension of the Port of Rotterdam in the Netherlands, approximately 220 million m 3 sand was extracted between 2009 and 2013. In order to decrease the surface area of direct impact, the authorities permitted deep sand extraction, down to 20 m below the seabed. Biological and physical impacts of large-scale and deep sand extraction are still being investigated and largely unknown. For this reason, we investigated the colonization of demersal fish in a deep sand extraction site. Two sandbars were artificially created by selective dredging, copying naturally occurring meso-scale bedforms to increase habitat heterogeneity and increasing post-dredging benthic and demersal fish species richness and biomass. Significant differences in demersal fish species assemblages in the sand extraction site were associated with variables such as water depth, median grain size, fraction of very fine sand, biomass of white furrow shell ( Abra alba ) and time after the cessation of sand extraction. Large quantities of undigested crushed white furrow shell fragments were found in all stomachs and intestines of plaice ( Pleuronectes platessa ), indicating that it is an important prey item. One and two years after cessation, a significant 20-fold increase in demersal fish biomass was observed in deep parts of the extraction site. In the troughs of a landscaped sandbar however, a significant drop in biomass down to reference levels and a significant change in species assemblage was observed two years after cessation. The fish assemblage at the crests of the sandbars differed significantly from the troughs with tub gurnard ( Chelidonichthys lucerna ) being a Dufrene-Legendre indicator species of the crests. This is a first indication of the applicability of landscaping techniques to induce heterogeneity of the seabed although it remains difficult to draw a strong conclusion due the lack of replication in the experiment. A new ecological equilibrium is not reached after 2 years since biotic and abiotic variables are still adapting. To understand the final impact of deep and large-scale sand extraction on demersal fish, we recommend monitoring for a longer period, at least for a period of six years or even longer.

Host cytokine responses to Brucella abortus infection are elicited predominantly by the deployment of a type IV secretion system (T4SS). However, the mechanism by which the T4SS elicits inflammation remains unknown. Here we show that translocation of the T4SS substrate VceC into host cells induces proinflammatory responses. Ectopically expressed VceC interacted with the endoplasmic reticulum (ER) chaperone BiP/Grp78 and localized to the ER of HeLa cells. ER localization of VceC required a transmembrane domain in its N terminus. Notably, the expression of VceC resulted in reorganization of ER structures. In macrophages, VceC was required for B. abortus-induced inflammation by induction of the unfolded protein response by a process requiring inositol-requiring transmembrane kinase/endonuclease 1. Altogether, these findings suggest that translocation of the T4SS effector VceC induces ER stress, which results in the induction of proinflammatory host cell responses during B. abortus infection., IMPORTANCE Brucella species are pathogens that require a type IV secretion system (T4SS) to survive in host cells and to maintain chronic infection. By as-yet-unknown pathways, the T4SS also elicits inflammatory responses in infected cells. Here we show that inflammation caused by the T4SS results in part from the sensing of a T4SS substrate, VceC, that localizes to the endoplasmic reticulum (ER), an intracellular site of Brucella replication. Possibly via binding of the ER chaperone BiP, VceC causes ER stress with concomitant expression of proinflammatory cytokines. Thus, induction of the unfolded protein response may represent a novel pathway by which host cells can detect pathogens deploying a T4SS.

Netting the Bad Guys Antimicrobial peptides are an evolutionarily conserved component of innate immunity in the intestine. One family, α-defensins, typically exert their antimicrobial effects through microbicidal activity against bacteria. Humans express only two α-defensins, human defensin 5 (HD5) and HD6. HD5 exhibits bactericidal activity and plays a role in shaping the bacterial composition of the gut. HD6, on the other hand, does not show bactericidal activity and its function in the gut is unclear. Now, Chu et al. (p. 477 , published online 21 June; see the Perspective by Ouellette and Selsted ) show that HD6 protects against bacterial pathogens. Rather than killing them directly, HD6 binds to bacteria surface proteins and, through a process of self-assembly, forms fibrils and nanonets that ensnare invading bacterial pathogens.

A large number of hypothetical genes potentially encoding small proteins of unknown function are annotated in the Brucella abortus genome. Individual deletion of 30 of these genes identified four mutants, in BAB1_0355, BAB2_0726, BAB2_0470, and BAB2_0450 that were highly attenuated for infection. BAB2_0726, an YbgT-family protein located at the 3' end of the cydAB genes encoding cytochrome bd ubiquinal oxidase, was designated cydX. A B. abortus cydX mutant lacked cytochrome bd oxidase activity, as shown by increased sensitivity to H(2)O(2), decreased acid tolerance and increased resistance to killing by respiratory inhibitors. The C terminus, but not the N terminus, of CydX was located in the periplasm, suggesting that CydX is an integral cytoplasmic membrane protein. Phenotypic analysis of the cydX mutant, therefore, suggested that CydX is required for full function of cytochrome bd oxidase, possibly via regulation of its assembly or activity.

Brucellosis is a zoonotic infection caused primarily by the bacterial pathogens Brucella melitensis and B. abortus. It is acquired by consumption of unpasteurized dairy products or by contact with infected animals. Globally, it is one of the most widespread zoonoses, with 500,000 new cases reported each year. In endemic areas, Brucella infections represent a serious public health problem that results in significant morbidity and economic losses. An important feature of the disease is persistent bacterial colonization of the reticuloendothelial system. In this review we discuss recent insights into mechanisms of intracellular survival and immune evasion that contribute to systemic persistence by the pathogenic Brucella species.

In humans, pathogenic Brucella species cause a febrile illness known as brucellosis. A key pathogenic trait of this group of organisms is their ability to survive in immune cells and persist in tissues of the reticuloendothelial system, a process that requires the function of a Type IV secretion system. In contrast to other well-studied Gram-negative bacteria, Brucella spp. do not cause inflammation at the site of invasion, but have a latency period of 2-4 weeks before the onset of symptoms. This review discusses several mechanisms that allow Brucella spp. both to evade detection by pattern recognition receptors of the innate immune system and suppress their signalling. In contrast to these stealth features, the VirB Type IV secretion system, which mediates survival within phagocytic cells, stimulates innate immune responses in vivo. The responses stimulated by this virulence factor are sufficient to check bacterial growth, but not to elicit sterilizing immunity. The result is a stand-off between host and pathogen that results in persistent infection.

The Brucella abortus virB locus contains 12 open reading frames, termed virB1 through virB12 , which encode a type IV secretion system. Polar mutations in the virB locus markedly reduce the ability of B. abortus to survive in cultured macrophages or to persist in organs of mice. While a nonpolar deletion of the virB2 gene reduces survival in cultured macrophages and in organs of mice, a nonpolar deletion of virB1 only reduces survival in macrophages, whereas virB12 is dispensable for either virulence trait. Here we investigated the role of the remaining genes in the virB locus during survival in macrophages and virulence in mice. Mutants carrying nonpolar deletions of the virB3 , virB4 , virB5 , virB6 , virB7 , virB8 , virB9 , virB10 , or virB11 gene were constructed and characterized. All mutations reduced the ability of B. abortus to survive in J774A.1 mouse macrophage-like cells to a degree similar to that caused by a deletion of the entire virB locus. Deletion of virB3 , virB4 , virB5 , virB6 , virB8 , virB9 , virB10 , or virB11 markedly reduced the ability of B. abortus to persist in the spleens of mice at 8 weeks after infection. Interestingly, deletion of virB7 did not reduce the ability of B. abortus to persist in spleens of mice. We conclude that virB2 , virB3 , virB4 , virB5 , virB6 , virB8 , virB9 , virB10 , and virB11 are essential for virulence of B. abortus in mice, while functions encoded by the virB1 , virB7 , and virB12 genes are not required for persistence in organs with this animal model.

MisL is a Salmonella enterica serotype Typhimurium fibronectin binding protein whose expression is induced during infection of mice. T-POP transposon mutagenesis identified marT as a positive regulatory element controlling expression of a misL :: lacZYA transcriptional fusion. Gel shift analysis identified MarT as a transcriptional activator of the misL promoter.

The effects of dimethylsulfoxide, DMSO, and mercurial sulfhydryl reagents have been studied on water and small solute permeability of rat renal brush border membrane vesicles. Water and solute permeability was measured by mixing membrane vesicles with hypertonic solutions in a stopped-flow apparatus and following osmotically-induced changes in vesicular volume via changes in scattered light intensity. The rate constant of the fast osmotic shrinkage is proportional to the osmotic water permeability, while the rate constant of the slow reswelling phase is proportional to the solute permeability. Using mannitol as the osmotic agent, the osmotic shrinkage of rat renal brush border membrane vesicles followed a biphasic time course. 80% of the vesicles shrunk with a rate constant of approx. 50 s-1 and 20% with a rate constant of approx. 2 s-1. DMSO decreased dose-dependently the amplitude of the fast osmotic shrinkage, without affecting its rate constant. In contrast to DMSO, HgCl2 decreased the rate constant but not the amplitude of the fast osmotic shrinkage of renal brush border vesicles. Between 40-50 microM HgCl2, the inhibition of the fast osmotic shrinkage was completed. DMSO and HgCl2 increase the activation energy of water permeation in renal membranes from 3 to 12-15 kcal/mol. DMSO and HgCl2 did not affect the rate constant of the slow osmotic shrinkage of renal membrane vesicles and were also without effect on osmotic shrinkage of small intestinal brush border and pure phospholipid vesicles. In renal brush border membranes, HgCl2 at low concentrations (less than 10 microM) increased by 15-fold the permeability to NaCl and urea but not to mannitol, an effect which precedes the inhibition of water permeability at higher HgCl2 concentrations. The increase in small solute permeability was irreversible while the inhibition of water permeability could be reversed with cysteine and dithiothreitol. We conclude that water and small solute pathways in rat renal brush border membranes are completely separate entities, which are effected differently by DMSO and HgCl2. These pathways for water and solutes must be membrane proteins since neither DMSO nor HgCl2 affect the permeability properties of pure phospholipid vesicles.