Guinea pig ileum motility stimulation elicited by N-formyl-Met-Leu-Phe (fMLF) involves neurotransmitters and prostanoids

In guinea-pig ileum (GPI), the chemotactic peptide N-formyl-Met-Leu-Phe-OH (fMLF) possesses spasmogenic properties through the activation of formyl peptide receptors (FPRs). Despite this, the mediators involved remain to be elucidated. fMLF (1 nM-1 μM) induced a dose-dependent contraction of GPI (EC₅₀ = 24 nM), that is blocked by pre-treatment with the FPRs antagonist Boc₂. The pre-treatment with tetrodotoxin (TTX) atropine or with SR140333 reduced the fMLF-induced contraction, whereas with hexamethonium, MEN10627, SB222200, mepyramine, cimetidine, thioperamide or methysergide did not produce any effect. With DuP697 pre-treatment, but not with piroxicam, reduced the fMLF-induced contraction. After stimulation with 24 nM fMLF, a strong increase in the PGE₂ levels was observed. Finally, the concomitant blocking of the NK₁ receptor, the muscarinic receptors and COX-2 abolished the GPI contractions induced by fMLF.fMLF induced a concentration-dependent contraction of guinea-pig jejunum (EC₅₀ = 11 nM), proximal colon (EC₅₀ = 3.5 nM) and distal colon (EC₅₀ = 2.2 nM), with a time-course similar to that observed in GPI. In these preparations as well, the co-administration of atropine, SR140333 and DuP697 abolished the contractions induced by fMLF. Intraperitoneal injection of fMLF (0.1 or 1 μmol/kg) enhanced the gastrointestinal motility in mice, abolished by the co-administration of atropine, SR140333 and DuP697. In conclusion, we showed that fMLF exerts spasmogenic actions on guinea-pig intestine both in vitro and in vivo through the release of acetylcholine and substance P from myenteric motorneurons and through prostanoids, probably from the inflammatory cells of the enteric immune system.     

Lipid rafts in health and disease

Lipid rafts are sphingolipid- and cholesterol-rich domains of the plasma membrane which contain a variety of signalling and transport proteins. Different subtypes of lipid rafts can be distinguished according to their protein and lipid composition. Caveolae are types of rafts that are rich in proteins of the caveolin family (caveolin-1, -2 and -3) which present a distinct signalling platform. The importance of lipid raft signalling in the pathogenesis of a variety of conditions, such as Alzheimer's, Parkinson's, cardiovascular and prion diseases, systemic lupus erythematosus and HIV, has been elucidated over recent years and makes these specific membrane domains an interesting target for pharmacological approaches in the cure and prevention of these diseases. This Review analyses the importance of lipid raft proteins and lipids in health and disease, with a focus on the current state of knowledge.     

High-level expression and efficient purification of recombinant human long pentraxin PTX3 in Chinese hamster ovary cells

PTX3 is a secreted multimeric glycoprotein which plays a key role in innate immunity by activating the classical complement pathway through specific recognition of the C1q subunit. A method is described for the high level expression of the recombinant human PTX3 in Chinese hamster ovary cells (CHO), adapted to a suspension growth in spinner flasks containing a serum-free chemically defined medium and producing about 50 mg of PTX3/L of culture. A purification procedure to produce a homogeneous protein preparation from the supernatant, by means of anion exchange, hydroxyapatite and size exclusion chromatography, is also reported. This three-step protocol allows us to obtain PTX3 with a recovery yield close to 70%, a purity degree exceeding 95%, and a final host cell protein (HCP) content lower than 150 ppm. The recombinant purified PTX3 retains its biological activity, as demonstrated by C1q binding ELISA assay, and displays a complex quaternary structure characterized by a high secondary structure content quite different from human short pentraxin C-reactive protein (CRP) and serum amyloid P component (SAP), as determined by circular dichroism, fluorescence analysis, and native and SDS-PAGE experiments.     

Impact of assessment and intervention by a health and social care professional team in the emergency department on the quality,safety, and clinical effectiveness of care for older adults: A randomised controlled trial

BackgroundOlder adults frequently attend the emergency department (ED) and experience high rates of adverse events following ED presentation. This randomised controlled trial evaluated the impact of early assessment and intervention by a dedicated team of health and social care professionals (HSCPs) in the ED on the quality, safety, and clinical effectiveness of care of older adults in the ED.Methods and findingsThis single-site randomised controlled trial included a sample of 353 patients aged ≥65 years (mean age = 79.6, SD = 7.01; 59.2% female) who presented with lower urgency complaints to the ED a university hospital in the Mid-West region of Ireland, during HSCP operational hours. The intervention consisted of early assessment and intervention carried out by a HSCP team comprising a senior medical social worker, senior occupational therapist, and senior physiotherapist. The primary outcome was ED length of stay. Secondary outcomes included rates of hospital admissions from the ED; hospital length of stay for admitted patients; patient satisfaction with index visit; ED revisits, mortality, nursing home admission, and unscheduled hospital admission at 30-day and 6-month follow-up; and patient functional status and quality of life (at index visit and follow-up). Demographic information included the patient’s gender, age, marital status, residential status, mode of arrival to the ED, source of referral, index complaint, triage category, falls, and hospitalisation history. Participants in the intervention group (n = 176) experienced a significantly shorter ED stay than the control group (n = 177) (6.4 versus 12.1 median hours, p < 0.001). Other significant differences (intervention versus control) included lower rates of hospital admissions from the ED (19.3% versus 55.9%, p < 0.001), higher levels of satisfaction with the ED visit (p = 0.008), better function at 30-day (p = 0.01) and 6-month follow-up (p = 0.03), better mobility (p = 0.02 at 30 days), and better self-care (p = 0.03 at 30 days; p = 0.009 at 6 months). No differences at follow-up were observed in terms of ED re-presentation or hospital admission. Study limitations include the inability to blind patients or ED staff to allocation due to the nature of the intervention, and a focus on early assessment and intervention in the ED rather than care integration following discharge.ConclusionsEarly assessment and intervention by a dedicated ED-based HSCP team reduced ED length of stay and the risk of hospital admissions among older adults, as well as improving patient satisfaction. Our findings support the effectiveness of an interdisciplinary model of care for key ED outcomes.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03739515","term_id":"NCT03739515"}}NCT03739515; registered on 12 November 2018.

Marica Cassarino and colleagues evaluate an intervention for early assessment of older patients in emergency care.     

Human ES- and iPS-derived myogenic progenitors restore DYSTROPHIN and improve contractility upon transplantation in dystrophic mice

A major obstacle in the application of cell-based therapies for the treatment of neuromuscular disorders is obtaining the appropriate number of stem/progenitor cells to produce effective engraftment. The use of embryonic stem (ES) or induced pluripotent stem (iPS) cells could overcome this hurdle. However, to date, derivation of engraftable skeletal muscle precursors that can restore muscle function from human pluripotent cells has not been achieved. Here we applied conditional expression of PAX7 in human ES/iPS cells to successfully derive large quantities of myogenic precursors, which, upon transplantation into dystrophic muscle, are able to engraft efficiently, producing abundant human-derived DYSTROPHIN-positive myofibers that exhibit superior strength. Importantly, transplanted cells also seed the muscle satellite cell compartment, and engraftment is present over 11 months posttransplant. This study provides the proof of principle for the derivation of functional skeletal myogenic progenitors from human ES/iPS cells and highlights their potential for future therapeutic application in muscular dystrophies.     

Pre-analytical method for metabolic profiling of plant cell cultures of Passiflora garckei

Passiflora garckei cell cultures were used as a model to describe a reproducible sample preparation method. Solid phase extraction (SPE) was employed to isolate the plant metabolites for nuclear magnetic resonance (NMR) analysis and to subsequently detect the differences between yeast extract elicited and control cells. Compared with previous results obtained by using a Sephadex LH-20 column, SPE coupled with NMR spectroscopy improves the analysis of aromatic compounds e.g.: trans-feruloyl derivatives and trans-coumaroyl derivatives. Moreover, it decreases the concentration of sugars that usually overlap with many plant metabolite signals.     

The carbonyl scavenger carnosine ameliorates dyslipidaemia and renal function in Zucker obese rats

The metabolic syndrome is a risk factor that increases the risk for development of renal and vascular complications. This study addresses the effects of chronic administration of the endogenous dipeptide carnosine (β‐alanyl‐L‐histidine, L‐CAR) and of its enantiomer (β‐alanyl‐D‐histidine, D‐CAR) on hyperlipidaemia, hypertension, advanced glycation end products, advanced lipoxidation end products formation and development of nephropathy in the non‐diabetic, Zucker obese rat. The Zucker rats received a daily dose of L‐CAR or D‐CAR (30 mg/kg in drinking water) for 24 weeks. Systolic blood pressure was recorded monthly. At the end of the treatment, plasma levels of triglycerides, total cholesterol, glucose, insulin, creatinine and urinary levels of total protein, albumin and creatinine were measured. Several indices of oxidative/carbonyl stress were also measured in plasma, urine and renal tissue. We found that both L‐ and D‐CAR greatly reduced obese‐related diseases in obese Zucker rat, by significantly restraining the development of dyslipidaemia, hypertension and renal injury, as demonstrated by both urinary parameters and electron microscopy examinations of renal tissue. Because the protective effect elicited by L‐ and D‐CAR was almost superimposable, we conclude that the pharmacological action of L‐CAR is not due to a pro‐histaminic effect (D‐CAR is not a precursor of histidine, since it is stable to peptidic hydrolysis), and prompted us to propose that some of the biological effects can be mediated by a direct carbonyl quenching mechanism.     

Isoform-specific and Protein Kinase C-mediated Regulation of CTP:Phosphoethanolamine Cytidylyltransferase Phosphorylation

CTP:phosphoethanolamine cytidylyltransferase (Pcyt2) is the main regulatory enzyme for de novo biosynthesis of phosphatidylethanolamine by the CDP-ethanolamine pathway. There are two isoforms of Pcyt2, -α and -β; however, very little is known about their specific roles in this important metabolic pathway. We previously demonstrated increased phosphatidylethanolamine biosynthesis subsequent to elevated activity and phosphorylation of Pcyt2α and -β in MCF-7 breast cancer cells grown under conditions of serum deficiency. Mass spectroscopy analyses of Pcyt2 provided evidence for isoform-specific as well as shared phosphorylations. Pcyt2β was specifically phosphorylated at the end of the first cytidylyltransferase domain. Pcyt2α was phosphorylated within the α-specific motif that is spliced out in Pcyt2β and on two PKC consensus serine residues, Ser-215 and Ser-223. Single and double mutations of PKC consensus sites reduced Pcyt2α phosphorylation, activity, and phosphatidylethanolamine synthesis by 50–90%. The phosphorylation and activity of endogenous Pcyt2 were dramatically increased with phorbol esters and reduced by specific PKC inhibitors. In vitro translated Pcyt2α was phosphorylated by PKCα, PKCβI, and PKCβII. Pcyt2α Ser-215 was also directly phosphorylated with PKCα. Mapping of the Pcyt2α- and -β-phosphorylated sites to the solved structure of a human Pcyt2β showed that they clustered within and flanking the central linker region that connects the two catalytic domains and is a novel regulatory segment not present in other cytidylyltransferases. This study is the first to demonstrate differences in phosphorylation between Pcyt2 isoforms and to uncover the role of the PKC-regulated phosphorylation.     

Functional interaction of common gamma-chain and growth hormone receptor signaling apparatus

We previously reported on an X-linked SCID (X-SCID) patient, who also had peripheral growth hormone (GH) hyporesponsiveness and abnormalities of the protein phosphorylation events following GH receptor (GHR) stimulation. In the present study, we examined a potential role of common cytokine receptor gamma-chain (gammac) in GHR signaling using EBV-transformed lymphocytes from healthy subjects and gammac-negative X-SCID patients. We demonstrated that the proliferative response to GH stimulation of the B cell lines of gammac-negative patients was impaired despite a comparable cellular expression of GHR molecules to controls. In patients, after GH stimulation, no phosphorylation of STAT5 was observed. In addition, the molecule localization through confocal microscopy revealed that in B cell lines of patients no nuclear translocation of STAT5b following GH stimulation occurred differently from controls. Biochemical analysis of the nuclear extracts of gammac-negative cell lines provided further evidence that the amount of STAT5b and its phosphorylated form did not increase following GH stimulation. In patients, cells reconstituted with wild-type gammac abnormal biochemical and functional events were restored resulting in nuclear translocation of STAT5. Confocal experiments revealed that GHR and gammac were colocalized on the cell membrane. Our study demonstrates the existence of a previously unappreciated relationship between GHR-signaling pathway and gammac, which is required for the activation of STAT5b in B cell lines. These data also confirm that growth failure in X-SCID is primarily related to the genetic alteration of the IL2RG gene.