The role of apolipoprotein N-acyl transferase, Lnt, in the lipidation of factor H binding protein of Neisseria meningitidis strain MC58 and its potential as a drug target

BACKGROUND AND PURPOSE The level of cell surface expression of the meningococcal vaccine antigen, Factor H binding protein (FHbp) varies between and within strains and this limits the breadth of strains that can be targeted by FHbp-based vaccines. The molecular pathway controlling expression of FHbp at the cell surface, including its lipidation, sorting to the outer membrane and export, and the potential regulation of this pathway have not been investigated until now. This knowledge will aid our evaluation of FHbp vaccines. EXPERIMENTAL APPROACH A meningococcal transposon library was screened by whole cell immuno-dot blotting using an anti-FHbp antibody to identify a mutant with reduced binding and the disrupted gene was determined. KEY RESULTS In a mutant with markedly reduced binding, the transposon was located in the lnt gene which encodes apolipoprotein N-acyl transferase, Lnt, responsible for the addition of the third fatty acid to apolipoproteins prior to their sorting to the outer membrane. We provide data indicating that in the Lnt mutant, FHbp is diacylated and its expression within the cell is reduced 10 fold, partly due to inhibition of transcription. Furthermore the Lnt mutant showed 64 fold and 16 fold increase in susceptibility to rifampicin and ciprofloxacin respectively. CONCLUSION AND IMPLICATIONS We speculate that the inefficient sorting of diacylated FHbp in the meningococcus results in its accumulation in the periplasm inducing an envelope stress response to down-regulate its expression. We propose Lnt as a potential novel drug target for combination therapy with antibiotics

Euro+Med-Checklist Notulae, 14

Abstract: This is the fourteenth of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Apocynaceae, Compositae, Crassulaceae, Cyperaceae, Euphorbiaceae, Gramineae, Leguminosae, Nyctaginaceae, Onagraceae, Orobanchaceae, Rubiaceae, Solanaceae and Umbelliferae. It includes new country and area records and taxonomic and distributional considerations for taxa in Acalypha, Bupleurum, Carex, Datura, Epilobium, Eragrostis, Galium, Leontodon, Mirabilis, Nerium, Orobanche, Phelipanche, Rhinanthus, Saccharum, Sedum, Trifolium, Tripleurospermum and Willemetia. Citation For the whole article: Raab-Straube E. von & Raus Th. (ed.) 2021: Euro+Med-Checklist Notulae, 14.-Willdenowia 51: 355-369. For a single contribution (example): Bergmeier E. 2021: Leontodon longirostris (Finch & P. D. Sell) Talavera-Pp. 356-357 in: Raab-Straube E. von & Raus Th. (ed.), Euro+Med-Checklist Notulae, 14.-Willdenowia 51: 355-369. https://doi.org/10.3372/wi.51.51304 Version of record first published online on 30 November 2021 ahead of inclusion in December 2021 issue

Expression of type 2A protein phosphatases in cardiac health and disease

Cardiac physiology and hypertrophy is regulated by the phosphorylation status of many proteins, which is regulated (in part) by activity of the type 2A serine/threonine protein phosphatase family. Phosphatase activity of this family is conferred by the homologous PP2ACα/β, PP4C and PP6C catalytic subunits. Using quantitative PCR, gene expression of type 2A phosphatases showed that PP6C mRNA (5.07) expressed as relative units (RU) was higher than PP2ACα (3.52), PP2ACβ (3.24) and PP4C (4.54) in H9c2 cardiomyocytes. However, in adult rat ventricular myocytes (ARVM), PP4C mRNA (6.42) was higher than PP2ACα (2.52), PP2ACβ (3.93) and PP6C (4.96). Using Western immunoblotting, PP2ACα/β protein expression was similar in both H9c2 cardiomyocytes and ARVM. PP6C protein expression in ARVM was significantly higher (P<0.05) when compared to H9c2 cardiomyocytes, while PP4C protein expression in ARVM was undetectable. Additionally, we showed that 28 days of transverse aortic constriction in the mouse induced a ∼61% increase in the left ventricular (LV) mass index and a significant increase (p<0.01) in the expression of PP2ACα/β protein when compared to sham-operated LV myocardium. PP4C protein expression was not detectable in sham or hypertrophied LV myocardium, whereas PP6C protein expression was similar in both groups. This study illustrates the differences in the expression of the type 2A protein phosphatases in both H9c2 cardiomyocytes, ARVM and also highlights the importance of PP2A in cardiac pathological hypertrophy. Future work will aim to identify substrates of PP2ACα, PP2ACβ, PP4C and PP6C related to calcium regulation and hypertrophy in cardiomyocytes using small interfering RNA

Factors associated with sclerostin levels – A calcification inhibitor – In individuals with type 2 diabetes mellitus; Is autonomic neuropathy the missing link?

Background: Sclerostin inhibits bone formation and its expression is upregulated in the vasculature during the arterial calcification process as a counterregulatory mechanism preventing further calcification. Lower extremity arterial calcification (LEAC) is common in neuropathic patients with type 2 diabetes (T2DM). Herein, we investigated for associations between plasma sclerostin levels and diabetic neuropathy as well as LEAC in subjects with T2DM. Methods: A total of 74 individuals with and 76 without T2DMwere recruited. Plasma sclerostin levels were measured by ELISA. Diagnosis of cardiac autonomic neuropathy (CAN) was based on the battery of the four autonomic tests, while of somatosensory peripheral neuropathy (DPN) on neuropathy symptom score and neuropathy disability score. LEAC was assessed with conventional ankle and foot x-rays. Results: Plasma sclerostin levels were higher in participants with LEAC vs. those without LEAC in both diabetes and non-diabetes cohorts (p = 0.035 and p = 0.003, respectively). In the diabetes cohort, patients with CAN, but not with DPN, had higher sclerostin levels when compared with those without CAN (p &lt; 0.001). Multivariate analysis in the diabetes cohort demonstrated that sclerostin levels were associated positively with CAN and LEAC, while in the non-diabetes cohort there was a trend for a positive association with male gender and presence of LEAC. Conclusion: Plasma sclerostin levels are increased in individuals with LEAC irrespectively of diabetes status. In addition, plasma sclerostin concentrations are associated independently with LEAC and CAN in people with T2DM. © 2020 Elsevier Inc

Report from the kick-off meeting of the Cochrane Skin Group Core Outcome Set Initiative (CSG-COUSIN)

A major obstacle of evidence-based clinical decision making is the use of non-standardized, partly untested outcome measurement instruments. Core Outcome Sets (COSs) are currently developed in different medical fields to standardize and improve the selection of outcomes and outcome measurement instruments in clinical trials, in order to pool results of trials or to allow indirect comparison between interventions. A COS is an agreed minimum set of outcomes that should be measured and reported in all clinical trials of a specific disease or trial population. The international, multidisciplinary Cochrane Skin Group Core Outcome Set Initiative (CSG-COUSIN) aims to develop and implement COSs in dermatology, thus making trial evidence comparable and, herewith, more useful for clinical decision making. The inaugural meeting of CSG-COUSIN was held on 17-18 March 2015 in Dresden, Germany, as the exclusive theme of the Annual Cochrane Skin Group Meeting. In total, 29 individuals representing a broad mix of different stakeholder groups, professions, skills and perspectives attended. This report provides a description of existing COS initiatives in dermatology, highlights current methodological challenges in COS development, and presents the concept, aims and structure of CSG-COUSIN