Combinatorial CRISPR screen identifies fitness effects of gene paralogues.

Genetic redundancy has evolved as a way for human cells to survive the loss of genes that are single copy and essential in other organisms, but also allows tumours to survive despite having highly rearranged genomes. In this study we CRISPR screen 1191 gene pairs, including paralogues and known and predicted synthetic lethal interactions to identify 105 gene combinations whose co-disruption results in a loss of cellular fitness. 27 pairs influence fitness across multiple cell lines including the paralogues FAM50A/FAM50B, two genes of unknown function. Silencing of FAM50B occurs across a range of tumour types and in this context disruption of FAM50A reduces cellular fitness whilst promoting micronucleus formation and extensive perturbation of transcriptional programmes. Our studies reveal the fitness effects of FAM50A/FAM50B in cancer cells

The Nutritional Impact of Milk Beverages in Reducing Nutrient Inadequacy among Children Aged One to Five Years in the Philippines: A Dietary Modelling Study

Around half of Filipino children are not consuming any dairy products on a given day, which has shown to be associated with increased risk of inadequate nutrient intakes. The current study applies dietary modelling to assess the nutritional impact of meeting dairy recommendations in reducing nutrient inadequacy in children aged one to five years in the Philippines. Dietary intake data of Filipino children aged one to five years (n = 3864) were analyzed from the 8th National Nutrition Survey 2013. Children who did not meet national dairy recommendations were identified. Two scenarios were applied, based on two types of commonly consumed milk products by the survey participants. In scenario one, one serving of powdered milk was added to the diet of these children. In scenario two, one serving of a young children milk (YCM) or preschool children milk (PCM) was added to the diet of children aged one to two years and three to five years, respectively. Mean nutrient intakes and percentages of children with inadequate intakes were estimated before and after applying modelling scenarios. Scenario one demonstrated improvement in calcium, phosphorus, sodium, vitamin A and riboflavin intakes, while in scenario two, further improvement of intakes of a wider range of nutrients including iron, selenium, zinc, magnesium, potassium, vitamins C, D, E, thiamin, niacin, vitamins B6, and B12 was observed. In both scenarios, if all children would meet their dairy recommendations, theoretical reductions in population nutrient inadequacy would be observed for all micronutrients, for example, only 20% of children aged one to two years would be inadequate in vitamin A instead of the current 60%, iron inadequacy would see a 5% reduction, and approximately 10% reduction for calcium and 20% reduction for folate. The present study is the first to apply dietary modelling to assess the theoretical impact of meeting dairy recommendations on nutrient inadequacy in children in the Philippines. Dairy consumption should be encouraged as part of the strategy to reduce nutrient inadequacies. Calcium, iron, vitamins D, E, and folate are of concern in the Philippines as the level of inadequacies are extremely high in early years, YCM and PCM can help increase the intake of these nutrients

Timing and pattern of post-exercise protein ingestion affects whole body protein balance in healthy children: a randomized trial

The dose and timing of post-exercise protein ingestion can influence WBPB in adults, although comparable data from children are scarce. This study investigated how protein intake (both, amount and distribution) post-exercise can affect WBPB in physically active children. Thirty-five children (26 males; 9-13 years old) underwent a 5-d adaptation diet consuming 0.95 g protein·kg-1·d-1. To assess whole body protein kinetics over 6h and 24h of recovery, participants consumed 2 mg·kg-1 [15N]glycine before performing 3 × 20-min of variable intensity cycling. Fifteen grams of protein was distributed across 2 isoenergetic carbohydrate-containing beverages (i.e. 15 and 240 min post-exercise) containing reciprocal amounts of protein [i.e., 0 + 15 g, 5 + 10 g, 10 + 5 g and 15 + 0 g for Groups A-D, respectively]. Over the 6-h that included the exercise bout and the first beverage at 15 min post-exercise, WBPB (i.e. synthesis – breakdown) demonstrated a linear increase of 0.647 g·kg-1·d-1 per 1 g protein intake (PThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Impact of moderate dietary protein restriction on glucose homeostasis in a model of oestrogen deficiency.

The need to consume adequate dietary protein to preserve physical function during ageing is well recognized. However, the effect of protein intakes on glucose metabolism is still intensively debated. During age-related oestrogen withdrawal at the time of the menopause, it is known that glucose homeostasis may be impaired but the influence of dietary protein levels in this context is unknown. The aim of the present study is to elucidate the individual and interactive effects of oestrogen deficiency and suboptimal protein intake on glucose homeostasis in a preclinical model involving ovariectomy (OVX) and a 13-week period of a moderately reduced protein intake in 7-month-old ageing rats. To investigate mechanisms of action acting via the pancreas-liver-muscle axis, fasting circulating levels of insulin, glucagon, IGF-1, FGF21 and glycemia were measured. The hepatic lipid infiltration and the protein expression of GLUT4 in the gastrocnemius were analyzed. The gene expression of some hepatokines, myokines and lipid storage/oxidation related transcription factors were quantified in the liver and the gastrocnemius. We show that, regardless of the oestrogen status, moderate dietary protein restriction increases fasting glycaemia without modifying insulinemia, body weight gain and composition. This fasting hyperglycaemia is associated with oestrogen status-specific metabolic alterations in the muscle and liver. In oestrogen-replete (SHAM) rats, GLUT4 was down-regulated in skeletal muscle while in oestrogen-deficient (OVX) rats, hepatic stress-associated hyperglucagonaemia and high serum FGF21 were observed. These findings highlight the importance of meeting dietary protein needs to avoid disturbances in glucose homeostasis in ageing female rats with or without oestrogen withdrawal

Low-load resistance training during step-reduction attenuates declines in muscle mass and strength and enhances anabolic sensitivity in older men

Step-reduction (SR) in older adults results in muscle atrophy and an attenuated rise in postprandial muscle protein synthesis (MPS): anabolic resistance. Knowing that resistance exercise (RT) can enhance MPS, we examined whether RT could enhance MPS following 2 weeks of SR. In addition, as we postulated that SR may impair feeding-induced vasodilation limiting nutrient delivery to muscle, we also examined whether citrulline (CIT), as an arginine and nitric oxide precursor, could attenuate muscle anabolic resistance accompanying SR. We used a unilateral leg model to compare older subjects’ who had undergone SR to a loaded condition of SR plus RT (SR + RT). Thirty older men (70 ± 1 years) underwent 14 days of SR (<1500 steps/day) with supplementation of either 5 g/day CIT or glycine placebo. Throughout SR, subjects performed unilateral low-load RT thrice weekly. We assessed muscle protein synthesis in the postabsorptive and postprandial state (20 g whey isolate plus 15 g glycine or as micellar-whey with 5 g CIT or 15 g glycine, n = 10/group). As MPS was similar after ingestion of either whey isolate, micellar-whey, or micellar-whey + CIT data related to different dietary groups were collapsed to compare SR and SR + RT legs. Subjects’ daily steps were reduced by 80 ± 2% during SR (P < 0.001) compared with baseline. Leg fat-free mass decreased with SR (−124 ± 61 g) and increased in the SR + RT (+126 ± 68 g; P = 0.003). Myofibrillar FSR was lower (P < 0.0001) in the SR as compared with the SR + RT leg in the postabsorptive (0.026 ± 0.001%/h vs. 0.045 ± 0.001%/h) and postprandial states (0.055 ± 0.002%/h vs. 0.115 ± 0.003%/h). We conclude that low-load RT, but not supplementation with CIT, can attenuate the deleterious effects of SR in aging muscle