NOD2 receptor and the cytosolic protein kinase RIPK2 regulate NF-κB and MAP kinase signaling during bacterial infections, but the role of this immune axis during viral infections has not been addressed. We demonstrate that Nod2−/− and Ripk2−/− mice are hypersusceptible to influenza A virus infection. Ripk2−/− cells displayed defective mitophagy leading to enhanced mitochondrial superoxide production and accumulation of damaged mitochondria resulting in increased NLRP3 inflammasome activation and IL-18 production. RIPK2 regulated mitophagy in a kinase-dependent manner by phosphorylating the mitophagy inducer ULK1. Accordingly, Ulk1−/− cells displayed enhanced mitochondrial superoxide production and caspase-1 activation. These results demonstrate a role for NOD2-RIPK2 signaling in protection against virally triggered immunopathology by negatively regulating NLRP3 inflammasome activation and IL-18 production via ULK1-dependent mitophagy.

Nuclear magnetic resonance (NMR) spectroscopy is useful to determine molecular structure in tissues grown in vitro only if their fidelity, relative to native tissue, can be established. Here, we use multidimensional NMR spectra of animal and in vitro model tissues as fingerprints of their respective molecular structures, allowing us to compare the intact tissues at atomic length scales. To obtain spectra from animal tissues, we developed a heavy mouse enriched by about 20% in the NMR-active isotopes carbon-13 and nitrogen-15. The resulting spectra allowed us to refine an in vitro model of developing bone and to probe its detailed structure. The identification of an unexpected molecule, poly(adenosine diphosphate ribose), that may be implicated in calcification of the bone matrix, illustrates the analytical power of this approach.

An appreciable level of isotope labelling is essential for future NMR structure elucidation of mammalian biomaterials, which are either poorly expressed, or unexpressable, using micro-organisms. We present a detailed protocol for high level 13 C enrichment even in slow turnover murine biomaterials (fur keratin), using a customized diet supplemented with commercial labelled algal hydrolysate and formulated as a gel to minimize wastage, which female mice consumed during pregnancy and lactation. This procedure produced approximately eightfold higher fur keratin labelling in pups, exposed in utero and throughout life to label, than in adults exposed for the same period, showing both the effectiveness, and necessity, of this approach.Keywords Carbon-13 Á In vivo Á Fur keratin Á Bone collagen Á Labelling Á Mouse Biomacromolecular structure determination by NMR has been revolutionized by the availability of target molecules, proteins and nucleic acids, enriched in NMR active ( 13 C, 15 N) or effectively ''invisible'' ( 2 H) isotopes (Saxena et al. 2012;Verardi et al. 2012;Wagner 2010). These are usually, and increasingly routinely, prepared by producing the requisite quantities of the molecular targets in a micro-organism expression system, genetically engineered as necessary, with subsequent isolation and purification. Hitherto the overwhelming focus has been on the production of pure biomolecules for structure elucidation and intermolecular interaction studies, and in the case of solid-state NMR, ordered ensembles of small and fairly pure biomolecules. There is an ongoing effort to increase the molecular weight limits of structures elucidated by solid-state NMR, either of proteins associated with lipid membranes, or fibrils and supramolecular structures formed from soluble subunits. There is increasing realization that, important and enlightening as the resultant information is, this approach cannot be directly applied to a huge body of biomaterials, such as the large (over 300 amino acids per chain) fibrous proteins, most importantly the collagens and keratins, comprising the extracellular matrices (ECM) of connective and structural tissues such as bone, cartilage, skin, and hair. These materials present formidable challenges for atomic level structure determination for other reasons besides their sheer size. Repetitive sequences and structural motifs exacerbate already serious issues of spectral overlap, and the commonly used micro-organism expression systems cannot reproduce the complex and specific post-translational modifications necessary for faithful assembly into native structures and cellular function, or the folding and chaperoning machinery essential for ultimate conformational integrity. To extend the power of

We have prepared mouse fur extensively 13C,15N-labelled in all amino acid types enabling application of 2D solid state NMR techniques which establish covalent and spatial proximities within, and in favorable cases between, residues. 13C double quantum–single quantum correlation and proton driven spin diffusion techniques are particularly useful for resolving certain amino acid types. Unlike 1D experiments on isotopically normal material, the 2D methods allow the chemical shifts of entire spin systems of numerous residue types to be determined, particularly those with one or more distinctively shifted atoms such as Gly, Ser, Thr, Tyr, Phe, Val, Leu, Ile and Pro. Also the partial resolution of the amide signals into two signal envelopes comprising of α-helical, and β-sheet/random coil components, enables resolution of otherwise overlapped α-carbon signals into two distinct cross peak families corresponding to these respective secondary structural regions. The increase in resolution conferred by extensive labelling offers new opportunities to study the chemical fate and structural environments of specific atom and amino acid types under the influence of commercial processes, and therapeutic or cosmetic treatments.Electronic supplementary materialThe online version of this article (doi:10.1007/s10858-016-0056-7) contains supplementary material, which is available to authorized users.

Purpose: To investigate Ontario physiotherapists' knowledge and use of, and attitudes toward, non-steroidal anti-inflammatory drugs (NSAIDs) to identify whether there is a need for physiotherapists to receive education specific to NSAIDs. Method: An existing survey instrument was modified and tested by five Ontario physiotherapists. The final version was distributed electronically to approximately 4,400 Ontario Physiotherapy Association members as a self-administered online questionnaire. Results: A total of 294 physiotherapists responded to the survey (response rate=6.7%). Respondents demonstrated variability in their knowledge of NSAID contraindications, side effects, and drug interactions. Most respondents (62.6%) were incorrect or unsure about where and how to obtain most NSAIDs, and most demonstrated incorrect or uncertain knowledge of the relevant legislation. Despite this lack of knowledge, 50% of respondents recommend NSAIDs to their patients. Conclusions: Many Ontario physiotherapists who participated in this survey recommend NSAIDs to their patients despite having a variable understanding of the legislation and medication-related factors. A lack of thorough knowledge of risks and contraindications has implications for patient safety. Physiotherapists who incorporate medications into their practice should access comprehensive information on appropriate NSAID use and should inform themselves about legislative restrictions to ensure that associated treatment is provided in a manner that is evidence based, safe, and in keeping with regulatory boundaries.