New Insights on the Role of Bioactive Food Derivatives in Neurodegeneration and Neuroprotection.

Over the last three decades, neurodegenerative diseases have received increasing attention due to their frequency in the aging population and the social and economic burdens they are posing. In parallel, an era's worth of research in neuroscience has shaped our current appreciation of the complex relationship between nutrition and the central nervous system. Particular branches of nutrition continue to galvanize neuroscientists, in particular the diverse roles that bioactive food derivatives play on health and disease. Bioactive food derivatives are nowadays recognized to directly impact brain homeostasis, specifically with respect to their actions on cellular mechanisms of oxidative stress, neuroinflammation, mitochondrial dysfunction, apoptosis and autophagy. However, ambiguities still exist regarding the significance of the influence of bioactive food derivatives on human health. In turn, gut microbiota dysbiosis is emerging as a novel player in the pathogenesis of neurodegenerative diseases. Currently, several routes of communication exist between the gut and the brain, where molecules are either released in the bloodstream or directly transported to the CNS. As such, bioactive food derivatives can modulate the complex ecosystem of the gut-brain axis, thus, targeting this communication network holds promises as a neuroprotective tool. This review aims at addressing one of the emerging aspects of neuroscience, particularly the interplay between food bioactive derivatives and neurodegeneration. We will specifically address the role that polyphenols and omega-3 fatty acids play in preventing neurodegenerative diseases and how dietary intervention complements available pharmacological approaches.

Effects of maternal docosahexaenoic acid supplementation on brain development and neurodevelopmental outcomes of breastfed preterm neonates: protocol for a follow-up at preschool age of a randomised clinical trial (MOBYDIckPS).

INTRODUCTION: Docosahexaenoic acid (DHA), an omega-3 fatty acid, is important for brain development with possible implications in neurodevelopmental outcomes. In the two-arm, randomised, double-blind, placebo-controlled Maternal Omega-3 Supplementation to Reduce Bronchopulmonary Dysplasia in Very Preterm Infants trial, very preterm infants (<29 weeks' gestation) were supplemented in high doses of DHA or placebo until they reached 36 weeks' postmenstrual age. We propose a long-term neurodevelopmental follow-up of these children. This protocol details the follow-up at 5 years of age, which aims to (1) confirm our long-term recruitment capacity and (2) determine the spectrum of neurodevelopmental outcomes at preschool age following neonatal DHA supplementation. METHODS AND ANALYSIS: This long-term follow-up involves children (n=194) born to mothers (n=170) randomised to DHA (n=85) or placebo (n=85) from the five sites in Quebec when they will be 5 years' corrected age. The primary outcome measure is related to the long-term recruitment capacity, which we determined as successful if 75% (±10%, 95% CI) of the eligible children consent to the 5-year follow-up study. Interviews with mothers will be conducted to assess various aspects of neurodevelopment at preschool age (executive functions, behavioural problems, global development and health-related quality of life), evaluated with standardised neurodevelopmental questionnaires. In addition, a semistructured interview conducted in a subset of the mothers will be used to determine their acceptability and identify barriers and enablers to their eventual participation to the next phase of the trial. This follow-up study will require approximately 22 months to be completed. ETHICS AND DISSEMINATION: This study was approved by the CHU de Québec-Université Laval Research Ethics Board (MP-20-2022-5926). Mothers will provide informed consent before participating in this study. Findings will be disseminated through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT02371460.

Relative effectiveness and safety of pharmacotherapeutic agents for patent ductus arteriosus (PDA) in preterm infants: a protocol for a multicentre comparative effectiveness study (CANRxPDA).

INTRODUCTION: Patent ductus arteriosus (PDA) is the most common cardiovascular problem that develops in preterm infants and evidence regarding the best treatment approach is lacking. Currently available medical options to treat a PDA include indomethacin, ibuprofen or acetaminophen. Wide variation exists in PDA treatment practices across Canada. In view of this large practice variation across Canadian neonatal intensive care units (NICUs), we plan to conduct a comparative effectiveness study of the different pharmacotherapeutic agents used to treat the PDA in preterm infants. METHODS AND ANALYSIS: A multicentre prospective observational comparative-effectiveness research study of extremely preterm infants born <29 weeks gestational age with an echocardiography confirmed PDA will be conducted. All participating sites will self-select and adhere to one of the following primary pharmacotherapy protocols for all preterm babies who are deemed to require treatment.Standard dose ibuprofen (10 mg/kg followed by two doses of 5 mg/kg at 24 hours intervals) irrespective of postnatal age (oral/intravenous).Adjustable dose ibuprofen (oral/intravenous) (10 mg/kg followed by two doses of 5 mg/kg at 24 hours intervals if treated within the first 7 days after birth. Higher doses of ibuprofen up to 20 mg/kg followed by two doses of 10 mg/kg at 24 hours intervals if treated after the postnatal age cut-off for lower dose as per the local centre policy).Acetaminophen (oral/intravenous) (15 mg/kg every 6 hours) for 3-7 days.Intravenous indomethacin (0.1-0.3 mg/kg intravenous every 12-24 hours for a total of three doses). OUTCOMES: The primary outcome is failure of primary pharmacotherapy (defined as need for further medical and/or surgical/interventional treatment following an initial course of pharmacotherapy). The secondary outcomes include components of the primary outcome as well as clinical outcomes related to response to treatment or adverse effects of treatment. SITES AND SAMPLE SIZE: The study will be conducted in 22 NICUs across Canada with an anticipated enrollment of 1350 extremely preterm infants over 3 years. ANALYSIS: To examine the relative effectiveness of the four treatment strategies, the primary outcome will be compared pairwise between the treatment groups using χ2 test. Secondary outcomes will be compared pairwise between the treatment groups using χ2 test, Student's t-test or Wilcoxon rank sum test as appropriate. To further examine differences in the primary and secondary outcomes between the four groups, multiple logistic or linear regression models will be applied for each outcome on the treatment groups, adjusted for potential confounders using generalised estimating equations to account for within-unit-clustering. As a sensitivity analysis, the difference in the primary and secondary outcomes between the treatment groups will also be examined using propensity score method with inverse probability weighting approach. ETHICS AND DISSEMINATION: The study has been approved by the IWK Research Ethics Board (#1025627) as well as the respective institutional review boards of the participating centres. TRIAL REGISTRATION NUMBER: NCT04347720.

Proteoglycan 4 (PRG4) expression and function in dry eye associated inflammation.

Dry eye disease (DED) affects hundreds of millions of people worldwide. It is characterized by the production of inflammatory cytokines and chemokines as well as damaging matrix metalloproteinases (MMPs) at the ocular surface. While proteoglycan 4 (PRG4), a mucin-like glycoprotein present at the ocular surface, is most well known as a boundary lubricant that contributes to ocular surface integrity, it has been shown to blunt inflammation in various cell types, suggesting a dual mechanism of action. Recently, full-length recombinant human PRG4 (rhPRG4) has been shown to improve signs and symptoms of DED in humans. However, there remains a significant need for basic science research on rhPRG4's biological properties and its potential therapeutic mechanisms of action in treating DED. Therefore, the objectives of this study were to characterize endogenous PRG4 expression by telomerase-immortalized human corneal epithelial (hTCEpi) cells, examine whether exogenous rhPRG4 modulates cytokine and chemokine secretion in response to dry eye associated inflammation (TNFα and IL-1ß), explore interactions between rhPRG4 and MMP-9, and understand how experimental dry eye (EDE) in mice affects PRG4 expression. PRG4 secretion from hTCEpi cells was quantified by Western blot and expression visualized by immunocytochemistry. Cytokine/chemokine production was measured by ELISA and Luminex, while rhPRG4's effect on MMP-9 activity, binding, and expression was quantified using an MMP-9 inhibitor kit, surface plasmon resonance, and reverse transcription polymerase chain reaction (RT-PCR), respectively. Finally, EDE was induced in mice, and PRG4 was visualized by immunohistochemistry in the cornea and by Western blot in lacrimal gland lysate. In vitro results demonstrate that hTCEpi cells synthesize and secrete PRG4, and PRG4 secretion is inhibited by TNFα and IL-1ß. In response to these pro-inflammatory stresses, exogenous rhPRG4 significantly reduced the stimulated production of IP-10, RANTES, ENA-78, GROα, MIP-3α, and MIG, and trended towards a reduction of MIP-1α and MIP-1ß. The hTCEpi cells were also able to internalize fluorescently-labelled rhPRG4, consistent with a mechanism of action that includes downstream biological signaling pathways. rhPRG4 was not digested by MMP-9, and it did not modulate MMP-9 gene expression in hTCEpi cells, but it was able to bind to MMP-9 and inhibited in vitro activity of exogenous MMP-9 in the presence of human tears. Finally, in vivo results demonstrate that EDE significantly decreased immunolocalization of PRG4 on the corneal epithelium and trended towards a reduction of PRG4 in lacrimal gland lysate. Collectively these results demonstrate rhPRG4 has anti-inflammatory properties on corneal epithelial cells, particularly as it relates to mitigating chemokine production, and is an inhibitor of MMP-9 activity, as well as that in vivo expression of PRG4 can be altered in preclinical models of DED. In conclusion, these findings contribute to our understanding of PRG4's immunomodulatory properties in the context of DED inflammation and provide the foundation and motivation for further mechanistic research of PRG4's properties on the ocular surface as well as expanding clinical evaluation of its ability as a multifunctional therapeutic agent to effectively provide relief to those who suffer from DED.

Automated Indentation Demonstrates Structural Stiffness of Femoral Articular Cartilage and Temporomandibular Joint Mandibular Condylar Cartilage Is Altered in FgF2KO Mice.

OBJECTIVE: Employ an automated indentation technique, using a commercially available machine, to assess the effect of fibroblast growth factor 2 (FGF2) expression on structural stiffness over the surface of both murine femoral articular cartilage (AC) and temporomandibular joint (TMJ) mandibular condylar cartilage (MCC). DESIGN: Experiments were performed using 3-month-old female homozygote Fgf2KO mice with wild type (WT) littermates. After euthanization, isolated mandibles and hindlimbs were either processed for histology or subjected to automated indentation on a Biomomentum Mach-1 v500csst with a 3-axis motion controller in a phosphate buffered saline bath using a 0.3 mm spherical tip indenter. The effect of indentation depth on normal force was characterized, then structural stiffness was calculated and mapped at multiple positions on the AC and MCC. RESULTS: Automated indentation of the AC and TMJ MCC was successfully completed and was able to demonstrate both regional variation in structural stiffness and differences between WT and Fgf2KO mice. Structural stiffness values for Fgf2KO AC were significantly smaller than WT at both the medial/anterior (P < 0.05) and medial/posterior (P < 0.05) positions. Global Fgf2KO also lead to a decrease in MCC thickness of the TMJ compared with WT (P < 0.05) and increased structural stiffness values for Fgf2KO at both the posterior and anterior location (P < 0.05). CONCLUSIONS: Automated indentation spatially resolved differences in structural stiffness between WT and Fgf2KO tissue, demonstrating FGF2 expression affects femoral AC and TMJ MCC. This quantitative method will provide a valuable approach for functional characterization of cartilage tissues in murine models relevant to knee joint and TMJ health and disease.

Lubricin/proteoglycan 4 detected in vocal folds of humans and five other mammals.

OBJECTIVES/HYPOTHESIS: Lubricin/proteoglycan-4 (PRG4) lubricates connective tissues such as joints and tendon sheaths, enabling them to better withstand shearing and frictional forces during motion. We wondered whether PRG4 might play a role in phonation, as normal vocal folds withstand repetitive, high-velocity deformations remarkably well. As a first step, we tested whether PRG4 is expressed in vocal folds. STUDY DESIGN: Laboratory study. METHODS: Anatomical and molecular methods were applied to 47 larynges from humans, macaque (Macaca fascicularis), canines, pigs, calves, and rats. Immunohistochemistry (IHC), Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR) methods were used to test for the presence of PRG4. RESULTS: In all species, the true vocal fold lamina propria (TVF-LP) was positive for PRG4 by IHC, whereas immunoreactivity of the false vocal fold was weak or absent, depending on the species. Human TVF-LP was strongly stained across all layers. Immunoreactivity was seen variably on the vocal fold surface and within the vocal fold epithelium, in the conus elasticus and thyroglottic ligament, and at the tip of vocal process. Western blots of four humans and six pigs demonstrated immunoreactivity at appropriate molecular weight. qRT-PCR of pig tissues confirmed PRG4 mRNA expression, which was highest in the TVF-LP. CONCLUSIONS: PRG4 was found in phonatory tissues of six mammals. We suggest it might act as a lubricant within the lamina propria and possibly on the vocal fold surface, limiting phonation-related damage to vocal fold extracellular matrix and epithelium, and enhancing vocal efficiency by reducing internal friction (viscosity) within the vocal fold. LEVEL OF EVIDENCE: NA Laryngoscope, 129:E229-E237, 2019.

Maternal knowledge, attitudes and beliefs regarding gastroenteritis and rotavirus vaccine before implementing vaccination program: which key messages in light of a new immunization program?

In July 2010, the National Advisory Committee on Immunization (NACI) recommended the systematic administration of rotavirus vaccines for all infants in Canada. According to the Erickson and De Wals framework, multiple factors need to be evaluated before implementing such a decision, including the study of the acceptability of this vaccine by the general population. A cross-sectional survey was conducted from February 10 to February 18, 2011, at the Sherbrooke University Hospital Center in the province of Quebec. A questionnaire, based upon the Health Belief Model (HBM) and theoretical planned action, was self-administered to pregnant or early post-partum women. The variables collected included socio-demographic data, past experience with gastroenteritis, cues to vaccination and HBM dimensions. The associations between questionnaire variables and vaccination intention were assessed using univariate and multivariate analyses. Of the 343 respondents, only 29% had already heard about rotavirus vaccination and among these, the intention of vaccination was 74%. In multivariate analysis, having a perception of infant vulnerability to gastroenteritis (OR=2.3, 95% CI 1.3-4.0) and having no other child at home (OR=2.3, 95% CI 1.3-4.2) were factors positively associated with a higher intention of vaccination, contrary to having already heard about the rotavirus vaccine in the media (OR=0.5, 95% CI 0.2-0.9). The three cues independently associated with intention of vaccination were the reimbursement of the vaccine (OR=3.0, 95% CI 1.6-5.7), its recommendation by a doctor (OR=21.2, 95% CI 5.8-75.9) and its protection against the most severe forms of gastroenteritis (OR=4.4, 95% CI 1.4-13.6). To improve the success of this new vaccination program, several key messages should be integrated in the information made available to the general population: (1) rotavirus gastroenteritis is a mandatory infection for every child <5 years; (2) the vaccine is reimbursed and included in the provincial vaccination program; and (3) the vaccine protects against the worst forms of gastroenteritis. Finally, support should be offered to physicians as they play a key role in public acceptance of new vaccines.