Statin-triggered cell death in primary human lung mesenchyrnal cells involves p53-PUMA and release of Smac and Omi but not cytochrome c

Statins inhibit 3-hydroxy-3-methyl-glutarylcoenzyme CoA (HMG-CoA) reductase, the proximal enzyme forcholesterol biosynthesis. They exhibit pleiotropic effects and are linked to health benefits for diseasesincluding cancer and lung disease. Understanding their mechanism of action could point to new therapies,thus we investigated the response of primary cultured human airway mesenchymal cells, which play aneffector role in asthma and chronic obstructive lung disease (COPD), to simvastatin exposure. Simvastatininduced apoptosis involving caspase-9, -3 and -7, but not caspase-8 in airway smooth muscle cells andfibroblasts. HMG-CoA inhibition did not alter cellular cholesterol content but did abrogate de novocholesterol synthesis. Pro-apoptotic effects were prevented by exogenous mevalonate, geranylgeranylpyrophosphate and farnesyl pyrophosphate, downstream products of HMG-CoA. Simvastatin increasedexpression of Bax, oligomerization of Bax and Bak, and expression of BH3-only p53-dependent genes, PUMAand NOXA. Inhibition of p53 and silencing of p53 unregulated modulator of apoptosis (PUMA) expressionpartly counteracted simvastatin-induced cell death, suggesting a role for p53-independent mechanisms.Simvastatin did not induce mitochondrial release of cytochrome c, but did promote release of inhibitor ofapoptosis (IAP) proteins, Smac and Omi. Simvastatin also inhibited mitochondrial fission with the loss ofmitochondrial Drp1, an essential component of mitochondrial fission machinery. Thus, simvastatin activatesnovel apoptosis pathways in lung mesenchymal cells involving p53, IAP inhibitor release, and disruption ofmitochondrial fission

Three-year follow-up of a randomised controlled trial to reduce excessive weight gain in the first two years of life: protocol for the POI follow-up study

Abstract Background The Prevention of Overweight in Infancy (POI) study was a four-arm randomised controlled trial (RCT) in 802 families which assessed whether additional education and support on sleep (Sleep group); food, physical activity and breastfeeding (FAB group); or both (Combination group), reduced excessive weight gain from birth to 2 years of age, compared to usual care (Control group). The study had high uptake at recruitment (58 %) and retention at 2 years (86 %). Although the FAB intervention produced no significant effect on BMI or weight status at 2 years, the odds of obesity were halved in those who received the sleep intervention, despite no apparent effect on sleep duration. We speculate that enhanced self-regulatory behaviours may exist in the Sleep group. Self-regulation was not measured in our initial intervention, but extensive measures have been included in this follow-up study. Thus, the overall aim of the POI follow-up is to determine the extent to which augmented parental support and education on infant sleep, feeding, diet, and physical activity in the first 2 years of life reduces BMI at 3.5 and 5 years of age, and to determine the role of self-regulation in any such relationship. Methods/design We will contact all 802 families and seek renewed consent to participate in the follow-up study. The families have received no POI intervention since the RCT finished at 2 years of age. Follow-up data collection will occur when the children are aged 3.5 and 5 years (i.e. up to 3 years post-intervention). Outcomes of interest include child anthropometry, body composition (DXA scan), diet (validated food frequency questionnaire), physical activity (accelerometry), sleep (questionnaire and accelerometry), and self-regulation (questionnaires and neuropsychological assessment). Discussion Our follow-up study has been designed primarily to enable us to determine whether the intriguing benefit of the sleep intervention suggested at 2 years of age remains as children approach school age. However, cohort analyses will also investigate how BMI, self-regulation, and sleep consolidation develop during the early years. This information will be valuable to researchers and policy makers progressing the field of early childhood obesity prevention. Trial registration ClinicalTrials.gov number NCT00892983