Desiccation, thermal stress and associated mortality in Drosophila fruit flies induced by neuropeptide analogue treatment

Drosophila suzukii is a serious pest of soft fruit worldwide. With the global over-dependence on broad-spectrum pesticides, a strong imperative exists for more environmentally friendly and targeted methods of control. One promising avenue involves employing synthetic neuropeptide analogues as insecticidal agents to reduce pest fitness. Neuropeptides, central to the regulation of physiological and behavioural processes, play a vital role in cold and desiccation survival. Building upon this, the current study investigated the effects of biostable kinin, the cardioacceleratory peptide CAP2b and pyrokinin (PK) analogues (the latter of which have previously displayed cross-talk with the capa receptor), on desiccation, starvation and cold stress tolerance of the pest, D. suzukii, and the closely related non-pest, D. melanogaster. Results demonstrated analogues of the superfamily (CAP2b and PK derived) significantly impacted survival of the target insect under conditions of desiccation stress. However, these peptides enhanced desiccation stress survival in relation to controls, suggesting that they may act as antagonists of the capa signalling pathway in the Malpighian tubules. Of particular note was the ability of analogues 1895 (2Abf-Suc-FGPRLa) and 1902 (2Abf-Suc-FKPRLa) to impact D. suzukii but not D. melanogaster. A focus on native Drosophila CAP2b/PK and kinin sequences in analogue development may yield pure agonists with diuretic action that may reduce desiccation stress survival in the pest flies. In highlighting the PRXamide neuropeptide superfamily more generally, and the structures of promising analogues more specifically, this research will feed the evolution of next-generation analogues and drive forward the development of neuropeptidomimetic-based agents

Flexibility and extracellular opening determine the interaction between ligands and insect sulfakinin receptors

Despite their fundamental importance for growth, the mechanisms that regulate food intake are poorly understood. Our previous work demonstrated that insect sulfakinin (SK) signaling is involved in inhibiting feeding in an important model and pest insect, the red flour beetle Tribolium castaneum. Because the interaction of SK peptide and SK receptors (SKR) initiates the SK signaling, we have special interest on the structural factors that influence the SK-SKR interaction. First, the three-dimensional structures of the two T. castaneum SKRs (TcSKR1 and TcSKR2) were generated from molecular modeling and they displayed significance in terms of the outer opening of the cavity and protein flexibility. TcSKR1 contained a larger outer opening of the cavity than that in TcSKR2, which allows ligands a deep access into the cavity through cell membrane. Second, normal mode analysis revealed that TcSKR1 was more flexible than TcSKR2 during receptor-ligand interaction. Third, the sulfated SK (sSK) and sSK-related peptides were more potent than the nonsulfated SK, suggesting the importance of the sulfate moiety

Treatment with Glucocorticoids or Calcineurin Inhibitors in Primary FSGS

In primary FSGS, calcineurin inhibitors have primarily been studied in patients deemed resistant to glucocorticoid therapy. Few data are available about their use early in the treatment of FSGS. We sought to estimate the association between choice of therapy and ESRD in primary FSGS

Clinical Features and Outcomes of a Racially Diverse Population with Fibrillary Glomerulonephritis

Fibrillary glomerulonephritis is characterized by randomly arranged fibrils, approximately 20 nm in diameter by electron microscopy. Patients present with proteinuria, hematuria and kidney insufficiency, and about half of the reported patients progress to end-stage kidney disease within 4 years. The dependence of patient characteristics and outcomes on race has not been explored. In this study, we describe a cohort of patients with fibrillary glomerulonephritis and compare their clinical characteristics and outcomes with those of patients previously described

Predictors of treatment resistance and relapse in antineutrophil cytoplasmic antibody-associated small-vessel vasculitis: Comparison of two independent cohorts

Predictors of treatment resistance and relapse have been identified in patients with antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis in the Glomerular Disease Collaborative Network (GDCN) in the southeastern US. This study was undertaken to evaluate the applicability of those predictors in an independent cohort followed up by the French Vasculitis Study Group

Pathways to renal biopsy and diagnosis among patients with ANCA small-vessel vasculitis

Objectives—Antineutrophil cytoplasmic antibody small-vessel vasculitis (ANCA-SVV) is an autoimmune systemic process increasingly recognised since the advent of antibody testing for the disease. Prompt diagnosis and institution of immunosuppressive therapy has been shown to improve patient outcome. The goal of this study was to better understand how patients navigate the health care system from symptom presentation to biopsy diagnosis, and to study the effects of prompt versus delayed diagnosis. Methods—Disease symptoms and number of physicians seen prior to renal biopsy were assessed for 127 ANCA-SVV patients. Direct, delayed, and quest pathways to diagnosis and treatment of vasculitis were defined for both patients and providers. Kruskal-Wallis and Fisher exact tests were used to evaluate continual measures and compare categorical variables across pathways. Results—Among patients who sought direct care, physician delay in referral to a nephrologist was common (49/127, 71%, p=0.0023). Patients who delayed seeking care also experienced a delayed diagnosis 57% of the time (p=0.0023). Patients presenting with prodromal flu or upper respiratory involvement were more likely to have a delay/quest patient pathway (56% and 55%, respectively) than a direct patient pathway (44%, p=0.033 and 45%, p=0.019, respectively). There was a trend for patients with more severe loss of renal function to have a more direct referral to a nephrologist. Conclusion—Delay in diagnosis of ANCA SVV may be due to lack of or non-specific symptoms, especially in patients who present with non-renal manifestations of disease. Better algorithms are needed to identify extra-renal manifestations, expedite diagnosis and improve patient outcomes

The clinical course of ANCA small-vessel vasculitis on chronic dialysis

Antineutrophil cytoplasmic autoantibody (ANCA)-associated small-vessel vasculitis frequently affects the kidney. Here we describe the rates of infection, disease relapse, and death in patients with ANCA small-vessel vasculitis before and after end-stage renal disease (ESRD) in an inception cohort study and compare them to those of patients with preserved renal function. All patients had biopsy-proven ANCA small-vessel vasculitis. Fisher's exact tests and Wilcoxon rank sum tests were used to compare the characteristics by ESRD status. ESRD follow-up included time on dialysis with transplants censored. Over a median follow-up time of 40 months, 136 of 523 patients reached ESRD. ESRD was associated with new-onset ANCA small-vessel vasculitis in 51% of patients, progressive chronic kidney disease without active vasculitis in 43%, and renal relapse in 6% of patients. Relapse rates of ANCA small-vessel vasculitis, reported as episodes/person-year, were significantly lower on chronic dialysis (0.08 episodes) compared with the rate of the same patients before ESRD (0.20 episodes) or with patients with preserved renal function (0.16 episodes). Infections were almost twice as frequent among patients with ESRD on maintenance immunosuppressants and were an important cause of death. Given the lower risk of relapse and higher risk of infection and death, we suggest that immunosuppression be geared to patients with ESRD who present with active vasculitis

Bee‑safe peptidomimetic acaricides achieved by comparative genomics

The devastating Varroa mite (Varroa destructor Anderson and Trueman) is an obligatory ectoparasite of the honey bee, contributing to significant colony losses in North America and throughout the world. The limited number of conventional acaricides to reduce Varroa mites and prevent disease in honey bee colonies is challenged with wide-spread resistance and low target-site selectivity. Here, we propose a biorational approach using comparative genomics for the development of honey beesafe and selective acaricides targeting the Varroa mite-specific neuropeptidergic system regulated by proctolin, which is lacking in the honey bee. Proctolin is a highly conserved pentapeptide RYLPT (Arg-Tyr-Leu-Pro-Thr) known to act through a G protein-coupled receptor to elicit myotropic activity in arthropod species. A total of 33 different peptidomimetic and peptide variants were tested on the Varroa mite proctolin receptor. Ligand docking model and mutagenesis studies revealed the importance of the core aromatic residue Tyr2 in the proctolin ligand. Peptidomimetics were observed to have significant oral toxicity leading to the paralysis and death of Varroa mites, while there were no negative effects observed for honey bees. We have demonstrated that a taxon-specific physiological target identified by advanced genomics information offers an opportunity to develop Varroa miteselective acaricides, hence, expedited translational processes

Classification of antineutrophil cytoplasmic autoantibody vasculitides: The role of antineutrophil cytoplasmic autoantibody specificity for myeloperoxidase or proteinase 3 in disease recognition and prognosis

Anti-neutrophil cytoplasmic antibody (ANCA) vasculitis is a complex disease, with much debate about the utility of systems for classification and diagnosis. We compared three currently used classification systems in predicting disease prognosis

Peptidergic control in a fruit crop pest: The spotted-wing drosophila, Drosophila suzukii

Neuropeptides play an important role in the regulation of feeding in insects and offer potential targets for the development of new chemicals to control insect pests. A pest that has attracted much recent attention is the highly invasive Drosophila suzukii, a polyphagous pest that can cause serious economic damage to soft fruits. Previously we showed by mass spectrometry the presence of the neuropeptide myosuppressin (TDVDHVFLRFamide) in the nerve bundle suggesting that this peptide is involved in regulating the function of the crop, which in adult dipteran insects has important roles in the processing of food, the storage of carbohydrates and the movement of food into the midgut for digestion. In the present study antibodies that recognise the C-terminal RFamide epitope of myosuppressin stain axons in the crop nerve bundle and reveal peptidergic fibres covering the surface of the crop. We also show using an in vitro bioassay that the neuropeptide is a potent inhibitor (EC50 of 2.3 nM) of crop contractions and that this inhibition is mimicked by the non-peptide myosuppressin agonist, benzethonium chloride (Bztc). Myosuppressin also inhibited the peristaltic contractions of the adult midgut, but was a much weaker agonist (EC50 = 5.7 μM). The oral administration of Bztc (5 mM) in a sucrose diet to adult female D. suzukii over 4 hours resulted in less feeding and longer exposure to dietary Bztc led to early mortality. We therefore suggest that myosuppressin and its cognate receptors are potential targets for disrupting feeding behaviour of adult D. suzukii