The effects of maternal cigarette smoke exposure on brain health in offspring

University of Technology Sydney. Faculty of Science.There are approximately 1 billion smokers worldwide with three million in Australia. Cigarette smoking contributes to a number of chronic diseases such as cardiovascular and cerebrovascular diseases. Although it is well known that maternal cigarette smoke exposure (SE) is detrimental to the health of offspring, more than 20% of women still smoke when they are pregnant. Previous studies only focused on brain structure, sizes and aetiology of the offspring from the smokers. However, none have investigated the impact of maternal smoking on the markers of inflammation, oxidative stress and mitochondrial wellbeing in the offspring’s brain, whereas maternal smoking during pregnancy is linked to brain hypoxia-ischemic injury in the neonates and resulting cerebral palsy and associated disabilities in children. Mitochondrial integrity may play a key role, as they are the major powerhouse of the cells and vulnerable to increased oxidative stress. Mitophagy is a selective removal of damaged mitochondria by autophagy facilitated by fission and fusion. The former divides mitochondrion into healthy and damaged fragments; while the latter combines the healthy fragments to regenerate new mitochondria. Abnormal level of mitophagy markers have been observed in neurological conditions, such as stroke. Thus, this thesis aimed to study (1) the impact of maternal cigarette smoke exposure on brain markers of inflammation, oxidative stress, and mitophagy in both dams and offspring at different ages; (2) the gender differences in response to maternal SE; (3) the impact of maternal L-Carnitine (antioxidant) supplementation during pregnancy and lactation on brain mitophagy and autophagy markers in offspring, and; (4) the impact of maternal SE on hypoxic ischemic (HI) injury in male offspring. Virgin female Balb/c mice (6 weeks) were exposed to cigarette smoke (SE) or air (SHAM) 6 weeks prior to mating, during gestation and lactation. They were mated with male Balb/c mice (8 weeks). The pups were sacrificed at postnatal day (P) 1, P20 and 13 weeks for Aims 1-3 and P45 for Aim 4. In aim 4, hypoxic ischemic injury was induced in half of the litters via left carotid artery occlusion. Behaviour tests (novel objective recognition test, error ladder, grip test, and elevated plus maze test) were carried out in offspring with HI injury at P40 to assess motor and cognitive functions. The dams were sacrificed when the pups weaned. The brains of both dams and offspring were analysed by western blotting, immunohistochemistry, and real-time PCR for markers of inflammation, oxidative stress and mitochondrial wellbeing. It was found that brain inflammatory markers were increased in adult male SE offspring at 13 weeks, but not changed in female offspring by maternal SE. Brain endogenous antioxidant was reduced in male offspring, which was increased in female offspring by maternal SE. Mitochondrial oxidative phosphorylation (OXPHOS) complexes I, III and V were increased by maternal SE in male offspring but all OXPHOS complexes (I-V) were increased in female SE offspring. Brain cell damage was increased in male offspring but not in female offspring by maternal SE. Maternal L-Carnitine supplementation partially reversed the above-mentioned impacts of maternal SE in offspring’s brain, including brain cell injury. HI injury reduced motor and cognitive functional outcomes in both SHAM and SE offspring but maternal SE did not worsen it. However, HI injury increased brain inflammatory markers in SE offspring, as well as mitochondrial fission markers. Autophagy and mitochondrial fusion markers were reduced by HI injury in male SE offspring. Apoptotic markers were also increased in SE offspring with HI injury. In conclusion, maternal SE had adverse impact on the brain health in offspring with more impact on male offspring than females. Maternal L-Carnitine supplementation seems to partially reverse such maternal impact. Maternal SE can worsen the cellular outcome in the offspring’s brain. Interventions to improve mitochondrial function may be plausible to mitigate the adverse impact of maternal SE

Comparison of different cryotherapy recovery methods in elite junior cyclists

Background/objective: Cold water immersion (CWI) and active recovery treatment (ACT) are commonly used recovery treatments for athletes between exercise bouts, but they are sometimes limited by space and availability of equipment in training and competition venues. Therefore, the purpose of this study was to determine whether cold compression therapy (CCT) would provide the same effect as CWI and ACT as an alternative option in a hot environment. Methods: Eight elite male junior cyclists (age, 15.5 ± 1.2 years; height, 167.7 ± 3.3 cm; body mass, 57.3 ± 3.5 kg; peak oxygen uptake, 64.7 ± 4.3 mL/kg/min) completed a maximal cycling test to determine their peak power output (PPO) and oxygen uptake. Then they completed three tests using randomised recovery protocol of CWI, CCT and ACT for 15 minutes. Each test consisted of two 35-minute exercise bouts, with 5 minutes of warm-up, 15 minutes of cycling at 75% PPO and 15 minutes maximal trial. The two exercise bouts were separated by 60 minutes (5 minutes cool-down, 10 minutes preparation for recovery treatment, 15 minutes recovery treatment, and 30 minutes passive recovery). Results: There was no significant difference between average power output, blood lactate, rating of perceived exertion, and heart rate for two time-trial bouts for all recovery treatments. A significant decrease in core temperature was noted prior to the start of the second exercise bout for CWI. Conclusion: CCT, CWI and ACT are all useful recovery treatments between exercise bouts

Tenascin C in Lung Diseases

Tenascin C (TNC) is a multifunctional large extracellular matrix protein involved in numerous cellular processes in embryonic development and can be increased in disease, or under conditions of trauma or cell stress in adults. However, the role of TNC in lung diseases remains unclear. In this study, we investigated the expression of TNC during development, in offspring following maternal particulate matter (PM) exposure, asthma, chronic obstructive pulmonary disease (COPD) and lung cancer. TNC expression is increased during lung development in biopsy cells, endothelial cells, mesenchymal cells, and epithelial cells. Maternal PM exposure increased TNC and collagen deposition, which was not affected by the removal of PM exposure after pregnancy. TNC expression was also increased in basal epithelial cells and fibroblasts in patients with asthma and AT2 and endothelial cells in patients with COPD. Furthermore, there was an increase in the expression of TNC in stage II compared to stage IA lung cancer; however, overall survival analysis showed no correlation between levels of TNC and survival. In conclusion, TNC is increased during lung development, in offspring following maternal PM exposure, and in asthma, COPD, and lung cancer tissues. Therefore, targeting TNC may provide a novel therapeutic target for lung diseases

Differential Effects of ‘Vaping’ on Lipid and Glucose Profiles and Liver Metabolic Markers in Obese Versus Non-obese Mice

Tobacco smoking increases the risk of metabolic disorders due to the combination of harmful chemicals, whereas pure nicotine can improve glucose tolerance. E-cigarette vapour contains nicotine and some of the harmful chemicals found in cigarette smoke at lower levels. To investigate how e-vapour affects metabolic profiles, male Balb/c mice were exposed to a high-fat diet (HFD, 43% fat, 20kJ/g) for 16weeks, and e-vapour in the last 6weeks. HFD alone doubled fat mass and caused dyslipidaemia and glucose intolerance. E-vapour reduced fat mass in HFD-fed mice; only nicotine-containing e-vapour improved glucose tolerance. In chow-fed mice, e-vapour increased lipid content in both blood and liver. Changes in liver metabolic markers may be adaptive responses rather than causal. Future studies can investigate how e-vapour differentially affects metabolic profiles with different diets.</jats:p

E-Cigarette Aerosol Condensate Leads to Impaired Coronary Endothelial Cell Health and Restricted Angiogenesis

Cardiovascular disease (CVD) is a leading cause of mortality worldwide, with cigarette smoking being a major preventable risk factor. Smoking cessation can be difficult due to the addictive nature of nicotine and the withdrawal symptoms following cessation. Electronic cigarettes (e-Cigs) have emerged as an alternative smoking cessation device, which has been increasingly used by non-smokers; however, the cardiovascular effects surrounding the use of e-Cigs remains unclear. This study aimed to investigate the effects of e-Cig aerosol condensate (EAC) (0 mg and 18 mg nicotine) in vitro on human coronary artery endothelial cells (HCAEC) and in vivo on the cardiovascular system using a mouse model of ‘e-vaping’. In vitro results show a decrease in cell viability of HCAEC when exposed to EAC either directly or after exposure to conditioned lung cell media (p p p FKBPL (p ICAM-1 (p < 0.05 vs. sham) in murine hearts following exposure to electronic cigarette aerosol treatment containing a higher amount of nicotine. Immunohistochemistry also revealed an upregulation of FKBPL and ICAM-1 protein expression levels. This study showed that despite e-Cigs being widely used for tobacco smoking cessation, these can negatively impact endothelial cell health with a potential to lead to the development of cardiovascular disease

Sex-Dependent Responses to Maternal Exposure to PM2.5 in the Offspring

Objective: Particulate matter (PM) with a diameter of 2.5 &mu;m or less (PM2.5) can cross the blood-placental barrier causing adverse foetal outcomes. However, the impact of maternal exposure to low-levels of PM2.5 on liver health and the metabolic profile is unclear. This study aimed to investigate hepatic responses to long-term gestational low-dose PM2.5 exposure, and whether the removal of PM after conception can prevent such effects. Method: Female Balb/c mice (8 weeks) were exposed to PM2.5 (5 &mu;g/day) for 6 weeks prior to mating, during gestation and lactation to model living in a polluted environment (PM group). In a sub-group, PM2.5 exposure was stopped post-conception to model mothers moving to areas with clean air (pre-gestation, Pre) group. Livers were studied in 13-week old offspring. Results: Female offspring in both PM and Pre groups had increased liver triglyceride and glycogen levels, glucose intolerance, but reduced serum insulin and insulin resistance. Male offspring from only the Pre group had increased liver and serum triglycerides, increased liver glycogen, glucose intolerance and higher fasting glucose level. Markers of oxidative stress and inflammation were increased in females from PM and Pre groups. There was also a significant sex difference in the hepatic response to PM2.5 with differential changes in several metabolic markers identified by proteomic analysis. Conclusions: Maternal PM exposure exerted sex-dependent effects on liver health with more severe impacts on females. The removal of PM2.5 during gestation provided limited protection in the offspring&rsquo;s metabolism regardless of sex

Expression of kidney injury markers in offspring mice at W13.

<p>Renal mRNA expression of pro-fibrotic marker fibronectin (A) and collagen IV (B) did not change between the offspring from SE dams and control dams due to maternal smoke exposure at week (W)13. Pro-inflammatory marker MCP-1 (C) mRNA expression in offspring from SE dams was significantly higher compare to offspring from control dams at W13. n = 4–6. *p<0.05, maternal smoke exposure effect.</p

Forward and reverse sequences of the primers for rt-PCR.

<p>Forward and reverse sequences of the primers for rt-PCR.</p