Thesis (Ph.D.)--Ohio University, August, 2009. / Release of full electronic text on OhioLINK has been delayed until September 1, 2012. Includes bibliographical references (leaves 157-195)

Thesis (Ph.D.)--Ohio University, August, 2009. / Title from PDF t.p. Release of full electronic text on OhioLINK has been delayed until September 1, 2012. Includes bibliographical references (leaves 157-195)

In setting the AMDR for protein at 10-35% of daily energy, the Institute of Medicine acknowledged a lack of data regarding the safety of long-term intakes. The current study assessed the impact of chronic (17 months) protein consumption at the upper end of the AMDR on renal function, histology, and inflammation. Using plant and animal whole protein sources, female Sprague-Dawley rats (70 days old; n=8-11 at 4, 8, 12, or 17 mo.) were randomized to either a normal (NP; 15% of energy) or high protein (HP; 35% of energy) diet. Egg albumen and skim milk replaced carbohydrates in the HP diet. Diets were balanced for energy, fat, vitamins and minerals, and offered ad libitum. Renal function was analyzed by creatinine clearance and urinary protein levels. Glomerular hypertrophy, glomerulosclerosis and tubulointerstitial fibrosis were assessed on kidney sections. Kidney disease progression was determined by the measurement of transforming growth factor beta-1 (TGF-β1) and renal inflammation by the measurement of chemokines monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation normal T-cell expressed and secreted (RANTES). Rats consuming the HP compared to NP diet had ~17% higher kidney weights (P<0.0001) and ~4.8 times higher proteinuria (P<0.0001). There was a trend towards higher creatinine clearance with HP (P=0.055). Consistent with this, HP compared to NP rats had ~22% larger glomeruli (P<0.0001) and ~33% more glomerulosclerosis (P=0.0003). The HP diet had no significant effect on tubulointerstitial fibrosis and renal TGF-β1 levels and did not result in higher renal levels of MCP-1 and RANTES. In fact, per mg renal protein, HP rats had ~16% lower MCP-1 (P<0.0001) and ~34% lower levels of RANTES (P<0.0001) than NP. The absence of an increase in cytokine levels may be a reflection of the moderate changes in renal pathology observed in rats offered HP diets. These data in normal female rats suggest that protein intakes at the upper end of the AMDR are detrimental to kidney health in the long-term. While modest, this may have implications for individuals whose kidney function is compromised, especially given the prevalence of those unaware of their kidney disease within North America.

In setting the AMDR for protein at 10-35% of daily energy, the Institute of Medicine acknowledged a lack of data regarding the safety of long-term intakes. The current study assessed the impact of chronic (17 months) protein consumption at the upper end of the AMDR on renal function, histology, and inflammation. Using plant and animal whole protein sources, female Sprague-Dawley rats (70 days old; n=8-11 at 4, 8, 12, or 17 mo.) were randomized to either a normal (NP; 15% of energy) or high protein (HP; 35% of energy) diet. Egg albumen and skim milk replaced carbohydrates in the HP diet. Diets were balanced for energy, fat, vitamins and minerals, and offered ad libitum. Renal function was analyzed by creatinine clearance and urinary protein levels. Glomerular hypertrophy, glomerulosclerosis and tubulointerstitial fibrosis were assessed on kidney sections. Kidney disease progression was determined by the measurement of transforming growth factor beta-1 (TGF-β1) and renal inflammation by the measurement of chemokines monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation normal T-cell expressed and secreted (RANTES). Rats consuming the HP compared to NP diet had ~17% higher kidney weights (P<0.0001) and ~4.8 times higher proteinuria (P<0.0001). There was a trend towards higher creatinine clearance with HP (P=0.055). Consistent with this, HP compared to NP rats had ~22% larger glomeruli (P<0.0001) and ~33% more glomerulosclerosis (P=0.0003). The HP diet had no significant effect on tubulointerstitial fibrosis and renal TGF-β1 levels and did not result in higher renal levels of MCP-1 and RANTES. In fact, per mg renal protein, HP rats had ~16% lower MCP-1 (P<0.0001) and ~34% lower levels of RANTES (P<0.0001) than NP. The absence of an increase in cytokine levels may be a reflection of the moderate changes in renal pathology observed in rats offered HP diets. These data in normal female rats suggest that protein intakes at the upper end of the AMDR are detrimental to kidney health in the long-term. While modest, this may have implications for individuals whose kidney function is compromised, especially given the prevalence of those unaware of their kidney disease within North America.

The development of lean body mass (LBM) is closely linked to protein feeding. Along with resistance exercise protein feeding, or amino acid provision, stimulate muscle protein synthesis (MPS). Repeated stimulation of MPS above protein breakdown results in lean mass accretion. Many athletes aim to build or maintain LBM. The aim of this thesis was to better understand the relationship between LBM and protein feeding in trained individuals. This aim was studied in the applied setting and at whole body, muscle and molecular level. Chapter 2 revealed differences in total body mass and LBM between young rugby union players competing at different playing standards. Protein consumption was higher in players that played at a higher standard. The protein consumption of players at both playing standards was higher than current protein recommendations for athletes. The Under 20 (U20) rugby union players in Chapter 3 also consumed more protein than current recommendations state. Their dietary habits changed depending on their environment and they consumed more protein while in Six Nations (6N) camp compared with out of camp. Also, there were changes in dietary habits for individuals, however, those changes did not occur at the group level. Using the camp as an education tool for good nutrition habits could be advantageous. As a group, rugby union players’ body composition did not change from pre to post a 6N tournament. However, there was individual variation, which could be meaningful for the individual players. We provide evidence suggesting that in elite sport, athletes should be considered as individuals as well as part of a group if appropriate. The protein ribosomal protein S6 kinase 1 (p70S6K1) is part of the mammalian target of rapamycin complex 1 (mTORC1) pathway, which regulates MPS. The response of p70S6K1 activity was 62% greater following resistance exercise coupled with protein feeding compared with protein feeding alone in Chapter 3. P70S6K1 activity explained a small amount of the variation in previously published MPS data. The activity of the signalling protein p70S6K1 was unchanged in response to different doses of whey protein in Chapter 4 and 5. These data suggest that resistance exercise is a larger stimulus of p70S6K1 activity and when manipulating aspects of protein feeding p70S6K1 activation may be a limited measure. Consumption of 40 g of whey protein stimulated myofibrillar MPS to a greater extent than 20 g after a bout of whole body resistance exercise. The amount of LBM that the trained individual possessed did not influence this observed response. These data suggest that the amount of muscle mass exercised may influence the amount of protein required to increase MPS stimulation. For those engaging in whole body resistance exercise 20 g of protein is not sufficient to maximally stimulate MPS. The athletes in Chapters 2 and 3 of this thesis consumed more protein than current recommendations that do not take into account whole body exercise. Current post-exercise protein recommendations may no longer be optimal given this new information. Future work should directly investigate the MPS response to protein ingestion following resistance exercise engaging different amounts of muscle mass in well trained and elite populations. Identifying the protein dose required for maximal stimulation of MPS following whole body exercise would be an informative area of future research.

TITLE: Calories vs. Composition: The effect on dietary alterations on anthropometric measures and biochemical parameters in overweight women.LEARNING OUTCOME: To determine if a high-protein, low-carbohydrate, ad-libitum diet is more effective than an energy-restricted diet in promoting weight loss and improving blood lipid and insulin levels.ABSTRACT TEXT: Thirty overweight/obese (BMI: 25-35kg/m2), premenopausal women were matched for Body Mass Index (BMI) and randomly assigned to one of the two diets: (1) High Protein (HP) (30-40% protein, 40-55% fat, 10-20% CHO); (2) Energy Restricted (ER) (1200kcal/d, 20-25% fat, 15-20% protein, 55-60% CHO). Subjects were given weekly menus matching their assigned macronutrient and/or energy requirements to aid in meal planning and dietary compliance. Baseline and post-diet measures included height, weight, body composition, blood lipids (total cholesterol (TC), HDL, LDL< and triglycerides (TG)], and plasma insulin levels. There were no significant differences found among the two groups in any of the above-listed variables prior to the study. Twenty-three women completed the 6-week study (HP=11, ER= 12). Compliance to the diets was adequate as indicated by weekly 24-hour recalls and daily urinary ketone levels. Both groups lost a significant amount of weight and body fat (P<0.05), andweight and body fat losses were not significantly different between the groups. In addition, both groups experienced similar decreases in TG, TC, LDL, HDL, and insulin levels. These results indicate that a HP diet is no more effective than an ER diet in promoting favorable changes in body weight, body composition, blood lipids, and insulin levels. / Department of Family and Consumer Sciences

Animals acquire immunity against gastrointestinal (GI) nematode infection depending on their age and continual exposure to larvae, however, expression of this acquired immunity is often penalized during pregnancy and lactating period. This is described as periparturient relaxation in immunity (PPRI), and suggested to have nutritional basis. Although dietary protein has positive effect on immunity against GI nematode infection in mammalian host, we have not fully achieved to characterise the detailed interaction between PPRI and dietary protein. Therefore, this PhD aimed to further investigate this interaction in a well-established Nippostrongylus brasiliensis re-infected lactating rat model. Feeding high protein diet (HP) as opposed to low protein diet (LP) during pregnancy was necessary in maintaining sufficient maternal performances and systemic immune response (Chapter 2 and 3). Accumulation of host’s body protein reserve during pregnancy was significantly higher in HP fed animals compared to LP fed counterparts, which led to improvement in both maternal performances and immunity during the early stage of lactation. However, as lactation period progressed and re-infection of N. brasiliensis took place, importance of current dietary status, rather than the accumulated protein reserve, became evident for maternal performances and immunity. Indeed, animals fed HP during lactation showed significantly heavier pup weight compared to LP fed animals; HP animals showed higher serum immunoglobulin levels and reduced worm burden compared to LP. N. brasiliensis, however, goes through systemic migration, entering host’s skin and migrating to lung parenchyma through blood vessels before reaching the intestine. In Chapter 4, a detailed lung pathology study following N. brasiliensis infection was performed to generate data on the effects of the nematode in the lung of the rat host as such data were scarce. Rat host showed similar lung pathology to that of mice; up-regulation of genes related to type 2 immunity and development of emphysema-like pathology were observed following N. brasiliensis re-infection. In Chapter 5, the effect of dietary protein supplementation on lung and intestinal histology and gene expression analysis was investigated. It was shown that HP fed animals showed higher expression of genes related to type 2 immunity compared to LP in the lung. This effect of protein supplementation in the lung may have contributed to fewer worm burdens in HP fed rats compared to LP in the intestine. Dietary protein supplementation significantly affected the expression of genes related to goblet cells; it resulted in up-regulation of the expression of Retnlb and down-regulation of Agr2 and Tff3 in HP fed animals compared to LP. It is evident that dietary protein is modulating intestinal immunity, and this may be targeted towards specific pathways. In addition, the effect of dietary protein supplementation on immune cell populations of secondary lymphoid organs was analysed. Marked increase in the percentage of macrophage in the spleen and T cell in the mesenteric lymph node was observed following protein supplementation, highlighting the importance of dietary protein on systemic immunity during the parasite infection. These results demonstrate that dietary protein supplementation is effective for improving both maternal performances and immune responses, not only at the intestinal phase but also at the migrating phase, when animal is undergoing PPRI during N. brasiliensis infection. Such information is expected to define strategic utilisation of nutrient supply and to result in development of sustainable parasite control strategies in mammals.

Pregnancy loss remains a major source of economic cost to the equine industry. Frequently, the exact causes of pregnancy loss remain unknown. It has been shown, in other species, that increased dietary protein leading to elevated blood urea nitrogen concentrations (BUN) can be a factor in decreased survival of the early embryo. Our studies provided novel information regarding the effects of elevated BUN on endometrium and embryos from mares as well as insights on changes in their gene expression. Our first objective was to develop an experimental model to elevate BUN during diestrus using intravenous urea infusion. We analyzed the effects of an acute elevation in BUN on uterine and vaginal pH along with changes in the endometrial transcriptome of mares with RNA sequencing. There was a significant increase in BUN and a decrease in uterine pH in the urea group compared to the control group. A total of 193 genes were differentially expressed (DEG) between the urea and control groups. The DEG were predicted to be related to cell pH, ion homeostasis, changes in epithelial tissue, fatty acid metabolism, and solute carriers. Our second objective was to evaluate the effects of elevated BUN in the endometrium of mares using a chronic oral urea administration to elevate BUN in mares. Uterine and vaginal pH were evaluated and RNA sequencing of the endometrium was again performed. There was an increase in BUN in the urea-fed mares, but no significant change in uterine or vaginal pH between the groups. A total of 60 DEG were characterized, with prediction of transcriptomic changes in the endometrium of mares related to cell death (necrosis) and cellular movement (invasion of cells). Our third objective was to determine the effects of a high BUN on the transcriptome of day-14 embryos. There was a positive correlation between plasma BUN and blastocoele fluid urea nitrogen concentration. Changes in embryo transcriptome were related to survival of organism, angiogenesis, adhesion, and quantity of cells. Our final objective was to evaluate the correlation between BUN and follicular fluid urea nitrogen and evaluate the survival of embryos collected from donor mares with high BUN concentrations. Urea nitrogen concentration was positively correlated between the plasma and follicular fluid of mares. Additionally, there was a higher pregnancy rate when embryos were collected from mares with lower BUN. Overall, these results further elucidate the mechanisms through which urea affects endometrial and embryonic transcriptome of mares with high BUN, serving to identify effects of a high BUN in the reproductive tract of mares that might lead to decreased fertility.

It has been suggested that high protein diets are associated with an increased risk of colorectal cancer due to the higher content of red meat. However, the study of the overall dietary and lifestyle pattern may prove more important than any individual component when assessing colorectal cancer risk. From this, it is proposed that a dietary pattern used for weight loss that is higher in protein but remains low in fat and high in foods rich in fibre and micronutrients that are required for genome stability may not increase the risk of colorectal cancer, thus providing a safe and effective dietary method of weight loss in overweight subjects. This thesis describes the development of a novel in vitro faecal water genotoxicity test using the cytokinesis-block micronucleus (CBMN) cytome assay in the WIL2-NS cell line. This thesis then investigates faecal water genotoxicity and peripheral blood lymphocyte genome stability in overweight men following a weight loss dietary pattern either high in protein, specifically red meat, or high in carbohydrate. Results from this thesis indicate that the genotoxic potential of faecal water can be successfully assessed in vitro using the CBMN cytome assay. A high protein-high red meat weight loss diet did not increase faecal water genotoxicity or peripheral blood lymphocyte DNA damage, measured with the CBMN cytome assay, differently to a high carbohydrate weight loss diet. Faecal water genotoxicity data suggests weight loss and/or caloric restriction following either a high protein or high carbohydrate diet may beneficially modify the carcinogenic load of the colon in the short term, however this needs to be validated in a study that includes a non-weight loss control group. A lack of relationship was seen between faecal water genotoxicity and genome damage in lymphocytes which may suggest that the assessment of both the genome damage potential of the bowel contents and the assessment of the genome stability profile of peripheral blood lymphocytes may be important in comprehensively assessing the impact on genome damage by different dietary patterns. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1316889 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008

Thesis (Ph.D.)--Baylor University, 2008. / Includes bibliographical references (p. 161-180)