Ablation of lysophosphatidic acid receptor 1 attenuates hypertrophic cardiomyopathy in a mouse model.

Myocardial fibrosis is a key pathologic feature of hypertrophic cardiomyopathy (HCM). However, the fibrotic pathways activated by HCM-causing sarcomere protein gene mutations are poorly defined. Because lysophosphatidic acid is a mediator of fibrosis in multiple organs and diseases, we tested the role of the lysophosphatidic acid pathway in HCM. Lysphosphatidic acid receptor 1 (LPAR1), a cell surface receptor, is required for lysophosphatidic acid mediation of fibrosis. We bred HCM mice carrying a pathogenic myosin heavy-chain variant (403+/-) with Lpar1-ablated mice to create mice carrying both genetic changes (403+/- LPAR1 -/-) and assessed development of cardiac hypertrophy and fibrosis. Compared with 403+/- LPAR1WT, 403+/- LPAR1 -/- mice developed significantly less hypertrophy and fibrosis. Single-nucleus RNA sequencing of left ventricular tissue demonstrated that Lpar1 was predominantly expressed by lymphatic endothelial cells (LECs) and cardiac fibroblasts. Lpar1 ablation reduced the population of LECs, confirmed by immunofluorescence staining of the LEC markers Lyve1 and Ccl21a and, by in situ hybridization, for Reln and Ccl21a. Lpar1 ablation also altered the distribution of fibroblast cell states. FB1 and FB2 fibroblasts decreased while FB0 and FB3 fibroblasts increased. Our findings indicate that Lpar1 is expressed predominantly by LECs and fibroblasts in the heart and is required for development of hypertrophy and fibrosis in an HCM mouse model. LPAR1 antagonism, including agents in clinical trials for other fibrotic diseases, may be beneficial for HCM.

Myofibroblast-specific inhibition of the Rho kinase-MRTF-SRF pathway using nanotechnology for the prevention of pulmonary fibrosis.

Pulmonary fibrosis is characterized by the accumulation of myofibroblasts in the lung and progressive tissue scarring. Fibroblasts exist across a spectrum of states, from quiescence in health to activated myofibroblasts in the setting of injury. Highly activated myofibroblasts have a critical role in the establishment of fibrosis as the predominant source of type 1 collagen and profibrotic mediators. Myofibroblasts are also highly contractile cells and can alter lung biomechanical properties through tissue contraction. Inhibiting signaling pathways involved in myofibroblast activation could therefore have significant therapeutic value. One of the ways myofibroblast activation occurs is through activation of the Rho/myocardin-related transcription factor (MRTF)/serum response factor (SRF) pathway, which signals through intracellular actin polymerization. However, concerns surrounding the pleiotropic and ubiquitous nature of these signaling pathways have limited the translation of inhibitory drugs. Herein, we demonstrate a novel therapeutic antifibrotic strategy using myofibroblast-targeted nanoparticles containing a MTRF/SRF pathway inhibitor (CCG-1423), which has been shown to block myofibroblast activation in vitro. Myofibroblasts were preferentially targeted via the angiotensin 2 receptor, which has been shown to be selectively upregulated in animal and human studies. These nanoparticles were nontoxic and accumulated in lung myofibroblasts in the bleomycin-induced mouse model of pulmonary fibrosis, reducing the number of these activated cells and their production of profibrotic mediators. Ultimately, in a murine model of lung fibrosis, a single injection of these drugs containing targeted nanoagents reduced fibrosis as compared with control mice. This approach has the potential to deliver personalized therapy by precisely targeting signaling pathways in a cell-specific manner, allowing increased efficacy with reduced deleterious off-target effects.

TSC2 inactivation, low mutation burden and high macrophage infiltration characterise hepatic angiomyolipomas.

AIMS: Although TSC1 or TSC2 inactivating mutations that lead to mTORC1 hyperactivation have been reported in hepatic angiomyolipomas (hAML), the role of other somatic genetic events that may contribute to hAML development is unknown. There are also limited data regarding the tumour microenvironment (TME) of hAML. The aim of the present study was to identify other somatic events in genomic level and changes in TME that contribute to tumorigenesis in hAML. METHODS AND RESULTS: In this study, we performed exome sequencing in nine sporadic hAML tumours and deep-coverage targeted sequencing for TSC2 in three additional hAML. Immunohistochemistry and multiplex immunofluorescence were carried out for 15 proteins to characterise the tumour microenvironment and assess immune cell infiltration. Inactivating somatic variants in TSC2 were identified in 10 of 12 (83%) cases, with a median allele frequency of 13.6%. Five to 18 somatic variants (median number: nine, median allele frequency 21%) not in TSC1 or TSC2 were also identified, mostly of uncertain clinical significance. Copy number changes were rare, but detection was impaired by low tumour purity. Immunohistochemistry demonstrated numerous CD68+ macrophages of distinct appearance from Küpffer cells. Multiplex immunofluorescence revealed low numbers of exhausted PD-1+/PD-L1+, FOXP3+ and CD8+ T cells. CONCLUSION: hAML tumours have consistent inactivating mutations in TSC2 and have a low somatic mutation rate, similar to other TSC-associated tumours. Careful histological review, standard IHC and multiplex immunofluorescence demonstrated marked infiltration by non-neoplastic inflammatory cells, mostly macrophages.

Endothelial-Specific Loss of Sphingosine-1-Phosphate Receptor 1 Increases Vascular Permeability and Exacerbates Bleomycin-induced Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease which leads to significant morbidity and mortality from respiratory failure. The two drugs currently approved for clinical use slow the rate of decline in lung function but have not been shown to halt disease progression or reverse established fibrosis. Thus, new therapeutic targets are needed. Endothelial injury and the resultant vascular permeability are critical components in the response to tissue injury and are present in patients with IPF. However, it remains unclear how vascular permeability affects lung repair and fibrosis following injury. Lipid mediators such as sphingosine-1-phosphate (S1P) are known to regulate multiple homeostatic processes in the lung including vascular permeability. We demonstrate that endothelial cell-(EC) specific deletion of the S1P receptor 1 (S1PR1) in mice (EC-S1pr1-/-) results in increased lung vascular permeability at baseline. Following a low-dose intratracheal bleomycin challenge, EC-S1pr1-/- mice had increased and persistent vascular permeability compared with wild-type mice, which was strongly correlated with the amount and localization of resulting pulmonary fibrosis. EC-S1pr1-/- mice also had increased immune cell infiltration and activation of the coagulation cascade within the lung. However, increased circulating S1P ligand in ApoM-overexpressing mice was insufficient to protect against bleomycin-induced pulmonary fibrosis. Overall, these data demonstrate that endothelial cell S1PR1 controls vascular permeability in the lung, is associated with changes in immune cell infiltration and extravascular coagulation, and modulates the fibrotic response to lung injury.

Childhood food insecurity and incident diabetes: A longitudinal cohort study of 34 042 children in Ontario, Canada.

AIM: To examine the association between childhood food insecurity and incident diabetes. METHODS: Using health administrative databases linked to the Canadian Community Health Survey, we conducted a population-based cohort study of children aged <18 years from Ontario, Canada. Children without diabetes who had a household response to the Canadian Community Health Survey Household Food Security Survey Module were followed for a median of 9.5 years for incident diabetes. Multivariable Cox proportional hazards models were used to examine the association between childhood food insecurity and incident diabetes, adjusted sequentially for important clinical and socio-economic risk factors. RESULTS: We included 34 042 children, of whom 5.3% lived in food-insecure households. There were 184 new cases of diabetes, diagnosed at a median age of 16 and 18.5 years in food-secure and food-insecure children, respectively. In unadjusted analysis, childhood food insecurity was associated with an increased risk of incident diabetes (hazard ratio 1.69, 95% CI 1.01 to 2.81). When adjusted for clinical and socio-economic confounders, the relationship was no longer statistically significant (hazard ratio 1.55, 95% CI 0.91 to 2.66, adjusted for clinical confounders; hazard ratio 1.30, 95% CI 0.72 to 2.37, adjusted for clinical/socio-economic confounders). Our results remained robust in sensitivity analyses. CONCLUSIONS: Although food-insecure children are a medically and socially vulnerable population, they do not appear to be at increased risk of incident diabetes over a median of 9.5 years.

Screening for YAP Inhibitors Identifies Statins as Modulators of Fibrosis.

Idiopathic pulmonary fibrosis is a lung disease with limited therapeutic options that is characterized by pathological fibroblast activation and aberrant lung remodeling with scar formation. YAP (Yes-associated protein) is a transcriptional coactivator that mediates mechanical and biochemical signals controlling fibroblast activation. In this study, we developed a high-throughput small-molecule screen for YAP inhibitors in primary human lung fibroblasts. Multiple HMG-CoA (hydroxymethylglutaryl-coenzyme A) reductase inhibitors (statins) were found to inhibit YAP nuclear localization via induction of YAP phosphorylation, cytoplasmic retention, and degradation. We further show that the mevalonate pathway regulates YAP activation, and that simvastatin treatment reduces fibrosis markers in activated human lung fibroblasts and in the bleomycin mouse model of pulmonary fibrosis. Finally, we show that simvastatin modulates YAP in vivo in mouse lung fibroblasts. Our results highlight the potential of small-molecule screens for YAP inhibitors and provide a mechanism for the antifibrotic activity of statins in idiopathic pulmonary fibrosis.

Vascular permeability in the fibrotic lung.

Idiopathic pulmonary fibrosis (IPF) is thought to result from aberrant tissue repair processes in response to chronic or repetitive lung injury. The origin and nature of the injury, as well as its cellular and molecular targets, are likely heterogeneous, which complicates accurate pre-clinical modelling of the disease and makes therapeutic targeting a challenge. Efforts are underway to identify central pathways in fibrogenesis which may allow targeting of aberrant repair processes regardless of the initial injury stimulus. Dysregulated endothelial permeability and vascular leak have long been studied for their role in acute lung injury and repair. Evidence that these processes are of importance to the pathogenesis of fibrotic lung disease is growing. Endothelial permeability is increased in non-fibrosing lung diseases, but it resolves in a self-limited fashion in conditions such as bacterial pneumonia and acute respiratory distress syndrome. In progressive fibrosing diseases such as IPF, permeability appears to persist, however, and may also predict mortality. In this hypothesis-generating review, we summarise available data on the role of endothelial permeability in IPF and focus on the deleterious consequences of sustained endothelial hyperpermeability in response to and during pulmonary inflammation and fibrosis. We propose that persistent permeability and vascular leak in the lung have the potential to establish and amplify the pro-fibrotic environment. Therapeutic interventions aimed at recognising and "plugging" the leak may therefore be of significant benefit for preventing the transition from lung injury to fibrosis and should be areas for future research.

Expanding the Boxmi Ligand Family: Synthesis and Application of NON and NSN Ligands.

Two synthetic strategies for a new family of neutral NON ligands featuring a "bis(oxazolinylmethylidene)isobenzofuran" framework (boxman) are reported. A Pd-mediated cyclization reaction forming the isobenzofuran core constitutes the key reaction in the eight-step synthetic route to the nonbackbone-methylated target compound H,Rboxman. In contrast, the introduction of two additional methyl groups provides stereochemical control during backbone construction and thereby access to the methylated derivative Me,Rboxman, which was synthesized in five steps and improved yields. In addition, the synthetic sequence was transferred to the thio analogue, providing access to the NSN ligand H,Rboxmene. Subsequent complexation experiments with iron and cobalt chloride precursors afforded the four-coordinated chlorido complexes Me,RboxmanMCl2 (R = Ph, iPr; M = Fe, Co) and established the boxman family as trans-chelating, bidentate bis(oxazoline) ligands. Application of the latter in the nickel(II)- and zinc(II)-catalyzed α-fluorination of ß-ketoesters and oxindoles (up to 98% yield and 94% ee) demonstrated their suitability for enantioselective catalysis.

Reaction Pathways and Redox States in α-Selective Cobalt-Catalyzed Hydroborations of Alkynes.

Cobalt(II) alkyl complexes supported by a monoanionic NNN pincer ligand are pre-catalysts for the regioselective hydroboration of terminal alkynes, yielding the Markovnikov products with α:ß-(E) ratios of up to 97:3. A cobalt(II) hydride and a cobalt(II) vinyl complex appear to determine the main reaction pathway. In a background reaction the highly reactive hydrido species specifically converts to a coordinatively unsaturated cobalt(I) complex which was found to re-enter the main catalytic cycle.

Tackling N-Alkyl Imines with 3d Metal Catalysis: Highly Enantioselective Iron-Catalyzed Synthesis of α-Chiral Amines.

A readily activated iron alkyl precatalyst effectively catalyzes the highly enantioselective hydroboration of N-alkyl imines. Employing a chiral bis(oxazolinylmethylidene)isoindoline pincer ligand, the asymmetric reduction of various acyclic N-alkyl imines provided the corresponding α-chiral amines in excellent yields and with up to >99 % ee. The applicability of this base metal catalytic system was further demonstrated with the synthesis of the pharmaceuticals Fendiline and Tecalcet.

Versatile Oxidase and Dehydrogenase Activities of Bacterial Pyranose 2-Oxidase Facilitate Redox Cycling with Manganese Peroxidase In Vitro.

Pyranose 2-oxidase (POx) has long been accredited a physiological role in lignin degradation, but evidence to provide insights into the biochemical mechanisms and interactions is insufficient. There are ample data in the literature on the oxidase and dehydrogenase activities of POx, yet the biological relevance of this duality could not be established conclusively. Here we present a comprehensive biochemical and phylogenetic characterization of a novel pyranose 2-oxidase from the actinomycetous bacterium Kitasatospora aureofaciens (KaPOx) as well as a possible biomolecular synergism of this enzyme with peroxidases using phenolic model substrates in vitro A phylogenetic analysis of both fungal and bacterial putative POx-encoding sequences revealed their close evolutionary relationship and supports a late horizontal gene transfer of ancestral POx sequences. We successfully expressed and characterized a novel bacterial POx gene from K. aureofaciens, one of the putative POx genes closely related to well-known fungal POx genes. Its biochemical characteristics comply with most of the classical hallmarks of known fungal pyranose 2-oxidases, i.e., reactivity with a range of different monosaccharides as electron donors as well as activity with oxygen, various quinones, and complexed metal ions as electron acceptors. Thus, KaPOx shows the pronounced duality of oxidase and dehydrogenase similar to that of fungal POx. We further performed efficient redox cycling of aromatic lignin model compounds between KaPOx and manganese peroxidase (MnP). In addition, we found a Mn(III) reduction activity in KaPOx, which, in combination with its ability to provide H2O2, implies this and potentially other POx as complementary enzymatic tools for oxidative lignin degradation by specialized peroxidases.IMPORTANCE Establishment of a mechanistic synergism between pyranose oxidase and (manganese) peroxidases represents a vital step in the course of elucidating microbial lignin degradation. Here, the comprehensive characterization of a bacterial pyranose 2-oxidase from Kitasatospora aureofaciens is of particular interest for several reasons. First, the phylogenetic analysis of putative pyranose oxidase genes reveals a widespread occurrence of highly similar enzymes in bacteria. Still, there is only a single report on a bacterial pyranose oxidase, stressing the need of closing this gap in the scientific literature. In addition, the relatively small K. aureofaciens proteome supposedly supplies a limited set of enzymatic functions to realize lignocellulosic biomass degradation. Both enzyme and organism therefore present a viable model to study the mechanisms of bacterial lignin decomposition, elucidate physiologically relevant interactions with specialized peroxidases, and potentially realize biotechnological applications.

Constitutive expression and cell-surface display of a bacterial ß-mannanase in Lactobacillus plantarum.

BACKGROUND: Lactic acid bacteria (LAB) are important microorganisms in the food and beverage industry. Due to their food-grade status and probiotic characteristics, several LAB are considered as safe and effective cell-factories for food-application purposes. In this present study, we aimed at constitutive expression of a mannanase from Bacillus licheniformis DSM13, which was subsequently displayed on the cell surface of Lactobacillus plantarum WCFS1, for use as whole-cell biocatalyst in oligosaccharide production. RESULTS: Two strong constitutive promoters, Pgm and SlpA, from L. acidophilus NCFM and L. acidophilus ATCC4356, respectively, were used to replace the inducible promoter in the lactobacillal pSIP expression system for the construction of constitutive pSIP vectors. The mannanase-encoding gene (manB) was fused to the N-terminal lipoprotein anchor (Lp_1261) from L. plantarum and the resulting fusion protein was cloned into constitutive pSIP vectors and expressed in L. plantarum WCFS1. The localization of the protein on the bacterial cell surface was confirmed by flow cytometry and immunofluorescence microscopy. The mannanase activity and the reusability of the constructed L. plantarum displaying cells were evaluated. The highest mannanase activities on the surface of L. plantarum cells obtained under the control of the Pgm and SlpA promoters were 1200 and 3500 U/g dry cell weight, respectively, which were 2.6- and 7.8-fold higher compared to the activity obtained from inducible pSIP anchoring vectors. Surface-displayed mannanase was shown to be able to degrade galactomannan into manno-oligosaccharides (MOS). CONCLUSION: This work demonstrated successful displaying of ManB on the cell surface of L. plantarum WCFS1 using constitutive promoter-based anchoring vectors for use in the production of manno-oligosaccharides, which are potentially prebiotic compounds with health-promoting effects. Our approach, where the enzyme of interest is displayed on the cell surface of a food-grade organism with the use of strong constitutive promoters, which continuously drive synthesis of the recombinant protein without the need to add an inducer or change the growth conditions of the host strain, should result in the availability of safe, stable food-grade biocatalysts.

Square Planar Cobalt(II) Hydride versus T-Shaped Cobalt(I): Structural Characterization and Dihydrogen Activation with PNP-Cobalt Pincer Complexes.

The carbazole-based pincer ligand R(CbzPNP)H (R = iPr, tBu) has been used for the synthesis and characterization of various low- and high-spin cobalt complexes. Upon treatment of the high-spin complexes R(CbzPNP)CoCl (2R-CoIICl) with NaHBEt3, the selective formation of cobalt(II) hydride 3 iPr-CoIIH and T-shaped cobalt(I) complex 4 tBu-CoI was observed, depending on the substituents at the phosphorus atoms. For an unambiguous characterization of the reaction products, a density functional theory (DFT) supported paramagnetic NMR analysis was carried out, which established the electron configuration and the oxidation states of the metal atoms, thus demonstrating the significant impact of ligand substitution on the outcome of the reaction. A distinct one-electron reactivity was found for 4 tBu-CoI in the dehalogenation of tBuCl and cleavage of PhSSPh. On the other hand, the CoI species displayed two-electron redox behavior in the oxidative addition of dihydrogen. The resulting dihydride complex 6 tBu-CoIII(H)2 was found to display sluggish reactivity toward alkenes, whereas the cobalt(II) hydride 3 iPr-CoIIH was successfully employed in the catalytic hydrogenation of unhindered alkenes. The stoichiometric hydrogenolysis of 8 iPr-CoIIBn at elevated pressure (10 bar) led to a rapid cleavage of the Co-C bond to yield hydride complex 3 iPr-CoIIH. On the other hand, treatment of 2 iPr-CoIICl with phenethylmagnesium chloride directly resulted in the formation of 3 iPr-CoIIH, indicating facile ß-H elimination of the alkene insertion product (reversibly) generated in the catalytic hydrogenation. On the basis of these observations, a mechanistic pathway involving a key σ-bond metathesis step of the CoII-alkyl species is proposed.

The Rho Kinase Isoforms ROCK1 and ROCK2 Each Contribute to the Development of Experimental Pulmonary Fibrosis.

Pulmonary fibrosis is thought to result from dysregulated wound repair after repetitive lung injury. Many cellular responses to injury involve rearrangements of the actin cytoskeleton mediated by the two isoforms of the Rho-associated coiled-coil-forming protein kinase (ROCK), ROCK1 and ROCK2. In addition, profibrotic mediators such as transforming growth factor-ß, thrombin, and lysophosphatidic acid act through receptors that activate ROCK. Inhibition of ROCK activation may be a potent therapeutic strategy for human pulmonary fibrosis. Pharmacological inhibition of ROCK using nonselective ROCK inhibitors has been shown to prevent fibrosis in animal models; however, the specific roles of each ROCK isoform are poorly understood. Furthermore, the pleiotropic effects of this kinase have raised concerns about on-target adverse effects of ROCK inhibition such as hypotension. Selective inhibition of one isoform might be a better-tolerated strategy. In the present study, we used a genetic approach to determine the roles of ROCK1 and ROCK2 in a mouse model of bleomycin-induced pulmonary fibrosis. Using ROCK1- or ROCK2-haploinsufficient mice, we found that reduced expression of either ROCK1 or ROCK2 was sufficient to protect them from bleomycin-induced pulmonary fibrosis. In addition, we found that both isoforms contribute to the profibrotic responses of epithelial cells, endothelial cells, and fibroblasts. Interestingly, ROCK1- and ROCK2-haploinsufficient mice exhibited similar protection from bleomycin-induced vascular leak, myofibroblast differentiation, and fibrosis; however, ROCK1-haploinsufficient mice demonstrated greater attenuation of epithelial cell apoptosis. These findings suggest that selective inhibition of either ROCK isoform has the potential to be an effective therapeutic strategy for pulmonary fibrosis.

One-Pot Sequential Kinetic Profiling of a Highly Reactive Manganese Catalyst for Ketone Hydroboration: Leveraging σ-Bond Metathesis via Alkoxide Exchange Steps.

A comprehensive experimental and computational mechanistic study of the highly enantioselective hydroboration of ketones catalyzed by a manganese(II) alkyl boxmi pincer complex is reported. The catalyst operates at low catalyst loadings (down to 0.01 mol %) under very mild conditions (typically -40 °C) and facilitates the reduction of both aryl alkyl and dialkyl ketones with excellent selectivity (up to >95%ee). Catalyst activation pathways were investigated, demonstrating that a manganese(II) hydride and a manganese(II) alkoxide species are part of the catalytic cycle and can be generated via σ-bond metathesis of the alkyl precursor with the borane or by alcoholysis. Extensive kinetic experiments based on a "one-pot sequential kinetic profiling" approach under various conditions in combination with kinetic simulations reveal that two catalytic cycles are effective with this earth-abundant base metal catalyst: (i) a minor MnH/borane-mediated insertion cycle, in which the subsequent, product-releasing metathesis step is rate determining ( k m = 0.076 s-1), giving a background reaction, which is zeroth order in substrate concentrations, and (ii) a major MnOR/borane-based alkoxide exchange process, leveraging the high-barrier metathesis via the affiliation to an insertion step. The latter features non-integer reaction orders in both reagents due to a combination of an adduct formation step ( k a = 2.12 M-1 s-1, k -a = 0.49 s-1) and a substrate insertion step of comparable rates ( k ai = 3.74 M-1 s-1). The kinetic findings are underpinned by high-level density functional theory calculations of the mechanism, control experiments, and kinetic isotope effect/Hammett/Eyring analysis in different concentration regimes. The study highlights the role of a rigorous mechanistic understanding of homogeneous catalytic processes in 3d metals for rational catalyst discovery and optimization.

Synthesis, Characterization, and Reactivity of a High-Spin Iron(II) Hydrido Complex Supported by a PNP Pincer Ligand and Its Application as a Homogenous Catalyst for the Hydrogenation of Alkenes.

This study focused on the synthesis and characterization of a range of low-valent, high-spin iron(II) complexes supported by a carbazole-based PNP pincer-type ligand. The addition of the lithiated ligand (PNP)Li to FeCl2(THF)1.5 yielded the chlorido complex (PNP)FeCl (1), which could be readily converted to the four-coordinate iron(II) alkyl complexes (PNP)FeR [R = CH2SiMe3 (3a), Me (3b), CH2Ph (3c)]. These iron(II) complexes were fully characterized by X-ray analysis and a comprehensive, density-functional-theory-assisted study with complete assignment of their paramagnetic 1H and 13C NMR spectra. Treatment of 1 with KHBEt3 or the addition of molecular hydrogen to (PNP)FeR afforded a high-spin iron(II) PNP hydrido complex, which was identified as the dimer [(PNP)Fe(µ-H)]2 (4) with two bridging hydrido ligands between the iron centers. Exposing complexes 1 and 4 to carbon monoxide led to the corresponding six-coordinate, diamagnetic complexes (PNP)Fe(CO)2Cl (2) and (PNP)Fe(CO)2H (5), of which 2 was present as cis/trans isomers. Furthermore, 4 was found to be an active catalyst for the hydrogenation of alkenes.

Ultrafast Iron-Catalyzed Reduction of Functionalized Ketones: Highly Enantioselective Synthesis of Halohydrines, Oxaheterocycles, and Aminoalcohols.

A molecularly defined chiral boxmi iron alkyl complex catalyzes the hydroboration of various functionalized ketones and provides the corresponding chiral halohydrines, oxaheterocycles (oxiranes, oxetanes, tetrahydrofurans, and dioxanes) and amino alcohols with excellent enantioselectivities (up to >99 %ee) and conversion efficiencies at low catalyst loadings (as low as 0.5 mol %). Turnover frequencies of greater than 40000 h-1 at -30 °C highlight the activity of this earth-abundant metal catalyst which tolerates a large number of functional groups.

Autotaxin activity increases locally following lung injury, but is not required for pulmonary lysophosphatidic acid production or fibrosis.

Lysophosphatidic acid (LPA) is an important mediator of pulmonary fibrosis. In blood and multiple tumor types, autotaxin produces LPA from lysophosphatidylcholine (LPC) via lysophospholipase D activity, but alternative enzymatic pathways also exist for LPA production. We examined the role of autotaxin (ATX) in pulmonary LPA production during fibrogenesis in a bleomycin mouse model. We found that bleomycin injury increases the bronchoalveolar lavage (BAL) fluid levels of ATX protein 17-fold. However, the LPA and LPC species that increase in BAL of bleomycin-injured mice were discordant, inconsistent with a substrate-product relationship between LPC and LPA in pulmonary fibrosis. LPA species with longer chain polyunsaturated acyl groups predominated in BAL fluid after bleomycin injury, with 22:5 and 22:6 species accounting for 55 and 16% of the total, whereas the predominant BAL LPC species contained shorter chain, saturated acyl groups, with 16:0 and 18:0 species accounting for 56 and 14% of the total. Further, administration of the potent ATX inhibitor PAT-048 to bleomycin-challenged mice markedly decreased ATX activity systemically and in the lung, without effect on pulmonary LPA or fibrosis. Therefore, alternative ATX-independent pathways are likely responsible for local generation of LPA in the injured lung. These pathways will require identification to therapeutically target LPA production in pulmonary fibrosis.-Black, K. E., Berdyshev, E., Bain, G., Castelino, F. V., Shea, B. S., Probst, C. K., Fontaine, B. A., Bronova, I., Goulet, L., Lagares, D., Ahluwalia, N., Knipe, R. S., Natarajan, V., Tager, A. M. Autotaxin activity increases locally following lung injury, but is not required for pulmonary lysophosphatidic acid production or fibrosis.

Seasonal variation in hospital encounters with hypoglycaemia and hyperglycaemia.

AIM: To assess whether rates of hospital encounters with hypoglycaemia and hyperglycaemia display seasonal variation. METHODS: Time series analyses of the monthly rates of hospital encounters (emergency room visits or inpatient admissions) with hypoglycaemia and hyperglycaemia from 2003 to 2012 using linked healthcare databases in Ontario, Canada. RESULTS: Over the study period, there were 129 887 hypoglycaemia and 79 773 hyperglycaemia encounters. The characteristics of people at the time of their encounters were similar across the seasons in 2008 (median age 68 years for hypoglycaemia encounters and 53 years for hyperglycaemia encounters; 50% female; 90% with diabetes). We observed moderate seasonality in both types of encounters (R2 autoregression coefficient 0.58 for hypoglycaemia; 0.59 for hyperglycaemia). The rate of hypoglycaemia encounters appeared to peak between April and June, when on average, there was an additional 49 encounters per month (0.36 encounters per 100 000 persons per month) compared with the other calendar months (5% increase). The rate of hyperglycaemia encounters appeared to peak in January, when on average, there was an additional 69 encounters per month (0.50 encounters per 100 000 persons per month) compared with the other calendar months (11% increase). CONCLUSIONS: In our region, there is seasonal variation in the rate of hospital encounters with hypoglycaemia and hyperglycaemia. Our findings may help to highlight periods of vulnerability for people, may inform future epidemiological studies and may aid in the appropriate planning of healthcare resources.

Mechanism-Based Enantiodivergence in Manganese Reduction Catalysis: A Chiral Pincer Complex for the Highly Enantioselective Hydroboration of Ketones.

A manganese alkyl complex containing a chiral bis(oxazolinyl-methylidene)isoindoline pincer ligand is a precatalyst for a catalytic system of unprecedented activity and selectivity in the enantioselective hydroboration of ketones, thus producing preparatively useful chiral alcohols in excellent yields with up to greater than 99 % ee. It is applicable for both aryl alkyl and dialkyl ketone reduction under mild reaction conditions (TOF >450 h-1 at -40 °C). The earth-abundant base-metal catalyst operates at very low catalyst loadings (as low as 0.1 mol %) and with a high level of functional-group tolerance. There is evidence for the existence of two distinct mechanistic pathways for manganese-catalyzed hydride transfer and their role for enantiocontrol in the selectivity-determining step is presented.