Gestational diabetes, a common medical complication in pregnancy, may lead to severe fetal consequences if left untreated. A major concern with the use of antidiabetic drugs in pregnancy is the potential for placental transfer and fetal toxicity. The presence of endocytic pathways and several ABC transporter proteins has been demonstrated in the human placenta and are believed to play an important role in determining fetal exposure to drugs used in pregnancy. The objective of this thesis is to investigate the safety and transfer of the oral hypoglycemic agent, glyburide, and the new long acting insulin analog, insulin glargine, across the human placenta. The oral antidiabetic, glyburide, has been shown to be actively effluxed across the placenta in the fetal to maternal direction. The transport of glyburide in the presence of a breast cancer resistance protein (BCRP) inhibitor was investigated in the dually perfused human placenta model. The results of the perfusion studies indicate that BCRP plays a role in protecting the fetus from the accumulation of glyburide. Subsequently, cellular studies were carried out to determine the effect of the naturally occurring single nucleotide polymorphism within the coding region of BCRP (C421A/Q141K) on glyburide transport. Results suggest that glyburide transport may be reduced in the presence of the Q141K polymorphism. While insulin remains as the gold standard, the potential for maternal hypoglycemia with insulin injection has resulted in the development of insulin analogs. Insulin glargine, a human insulin analog, has a long half life with no pronounced peak when compared to currently used NPH insulin. Human placental perfusion experiments examining the extent and rate of transfer of insulin glargine across the placenta demonstrated that, at therapeutic concentrations, insulin glargine does not cross the placenta to a measurable extent. To further determine the fetal safety of insulin glargine therapy compared with NPH insulin, a systematic review and meta-analysis were performed. No evidence was identified for increased adverse fetal outcomes with the use of insulin glargine during pregnancy. Overall, the results of this research serve to provide improved treatment options for women with diabetes in pregnancy.

Gestational diabetes, a common medical complication in pregnancy, may lead to severe fetal consequences if left untreated. A major concern with the use of antidiabetic drugs in pregnancy is the potential for placental transfer and fetal toxicity. The presence of endocytic pathways and several ABC transporter proteins has been demonstrated in the human placenta and are believed to play an important role in determining fetal exposure to drugs used in pregnancy. The objective of this thesis is to investigate the safety and transfer of the oral hypoglycemic agent, glyburide, and the new long acting insulin analog, insulin glargine, across the human placenta. The oral antidiabetic, glyburide, has been shown to be actively effluxed across the placenta in the fetal to maternal direction. The transport of glyburide in the presence of a breast cancer resistance protein (BCRP) inhibitor was investigated in the dually perfused human placenta model. The results of the perfusion studies indicate that BCRP plays a role in protecting the fetus from the accumulation of glyburide. Subsequently, cellular studies were carried out to determine the effect of the naturally occurring single nucleotide polymorphism within the coding region of BCRP (C421A/Q141K) on glyburide transport. Results suggest that glyburide transport may be reduced in the presence of the Q141K polymorphism. While insulin remains as the gold standard, the potential for maternal hypoglycemia with insulin injection has resulted in the development of insulin analogs. Insulin glargine, a human insulin analog, has a long half life with no pronounced peak when compared to currently used NPH insulin. Human placental perfusion experiments examining the extent and rate of transfer of insulin glargine across the placenta demonstrated that, at therapeutic concentrations, insulin glargine does not cross the placenta to a measurable extent. To further determine the fetal safety of insulin glargine therapy compared with NPH insulin, a systematic review and meta-analysis were performed. No evidence was identified for increased adverse fetal outcomes with the use of insulin glargine during pregnancy. Overall, the results of this research serve to provide improved treatment options for women with diabetes in pregnancy.

Objectives Glyburide, an important drug for type 2 diabetes, has extremely poor aqueous solubility and resulting low bioavailability. This study describes the ability of hydroxybutenyl-β-cyclodextrin (HBenBCD) to form complexes with glyburide, with enhanced solubility and dissolution rate in vitro. Method Glyburide and glyburide-HBenBCD were evaluated in various test media known to simulate human gastrointestinal conditions in the fasted and fed states, respectively. Key findings At ~14 wt% drug load, in the presence of HBenBCD, an almost 400-fold increase in glyburide aqueous solubility was observed. In the presence of HBenBCD, glyburide solubility was also significantly improved in all physiologically relevant test media. Subsequent dissolution experiments confirmed the solubility study results; the dissolution rate and total amount of drug released were significantly increased. Conclusions Complexation with HBenBCD may be an effective way to increase the bioavailability of glyburide.

Résumé : Introduction : Le débat sur l’utilisation des hypoglycémiants oraux (HGO) dans le traitement du diabète gestationnel (DG) perdure. Plusieurs études ont montré que la metformine et le glyburide sont deux alternatives acceptables en grossesse. Malgré tout, l’insuline reste le choix de première intention pour le traitement du DG lorsque la diète et l’exercice physique ne suffisent plus. Les principaux arguments en faveur des HGO sont la possibilité d’une meilleure observance du traitement et une meilleure qualité de vie (QDV). Cependant, les études sur la QDV chez les femmes atteintes de DG sont rares et d’autres études sur le HGO sont nécessaires pour valider leur efficacité et innocuité dans le traitement du DG. Méthodes : Étude pilote; 73 patientes avec DG ont été randomisées au groupe HGO (metformine ± glyburide, et ajout d’insuline au besoin) ou au groupe insuline. L’objectif primaire est de comparer, entre les deux groupes, la préférence du traitement ainsi que plusieurs aspects de la QDV (état de santé général, bien-être général, satisfaction quant au traitement du diabète et dépression post-natale). Les objectifs secondaires étaient de comparer le contrôle glycémique maternel et les issues maternelles et néonatales. Résultats : Des 73 femmes recrutées, 68 ont été incluses pour analyses. Dans le groupe HGO (n=34), 35,3% des participantes ont reçu de l’insuline. Plus de femmes dans le groupe HGO ont mentionné préférer recevoir le même traitement pour une prochaine grossesse (72.7% vs. 42,4%, p=0.01) si un traitement s’avérait nécessaire. Aucune différence n’est ressortie pour l’état de santé général, le bien-être général, la satisfaction quant au traitement et la dépression post-natale. Le taux moyen d’hypoglycémies maternelles (glycémie < 3.3 mmol/L) était supérieur dans le groupe HGO (0.8 vs. 0.1, p=0.008). Il n’y a eu aucune différence dans les autres complications maternelles et néonatales. Conclusion : La QDV est similaire dans les deux groupes mais, si un traitement pharmacologique s’avérait nécessaire lors d’une prochaine grossesse, les femmes préfèreraient débuter par les HGO. L’utilisation des HGO n’était pas associée à une hausse cliniquement significative des complications maternelles et néonatales. / Abstract: Background: The use of oral hypoglycemic agents (OHA) in gestational diabetes mellitus (GDM) is still debated. Insulin remains the first line treatment after diet failure. We hypothesized that OHA allows for better quality of life (QOL) in women with GDM and that the y prefer OHA to insulin therapy. Methods: Pilot study; 73 women with GDM were randomly assigned to the OHA group (metformin ± glyburide ± supplementary insulin, as needed) or the insulin group. General health, well-being, and treatment satisfaction using established questionnaires (SF-36, Well-Being Questionnaire and Diabetes Treatment Satisfaction Questionnaire) were respectively assessed at randomization, 38 weeks, and postpartum. Treatment preference and depression were assessed 8 weeks postpartum using the MIG questionnaire and the Short-form Edinburgh Depression Scale. Our primary outcomes were 1) preference of treatment and 2) QOL. Secondary outcomes included maternal glycemic control (hypoglycemia defined as plasma glucose < 3.3 mmol/L), as well as gestational and neonatal complications. Results: Analyses were performed in 68 women. In the OHA group (n= 34), 35.3% women received insulin therapy. More women in the OHA group than in the insulin group preferred their assigned treatment for another pregnancy (72.7% vs. 42.4%, p < 0.01) if a treatment is needed. No statistical differences between groups were found for the 3 items of QOL, the depression score, and neonatal complications. The mean rate of maternal hypoglycemia was higher in the OHA group (0. 8 vs. 0.1, p < 0.008). No statistical differences were found for other maternal and neonatal issues. Conclusion: Women declared to prefer OHA to insulin for a subsequent pregnancy complicated by GDM. QOL was similar in both groups. Use of OHA was not associated to clinically significant differences in maternal and neonatal complications.

Alzheimer’s disease is a devastating neurodegenerative disorder and the leading cause of dementia. The disease manifests via several pathologies including neuroinflammation, oxidative stress, metal ion dyshomeostasis, and cell death. To address the multifaceted nature of this disorder, the design of several diverse compounds, targeting many pathological effects, was generated. First, a series of compounds based on curcumin and diosgenin were synthesized following the bivalent design strategy. Two compounds were discovered to have neuroprotective ability, anti-oxidative function, and anti-Aß oligomerization (AßO) properties. A second set of molecules was also designed, wherein a hybrid compound strategy was utilized. Three hybrids were to shown to protect MC65 cells from Aß-induced toxicity and to have significant anti-oxidative activity. Mechanistic studies propose that protection is through disruption of interactions between AßOs and partner proteins. Furthermore, one hybrid was also shown to be able to pass the BBB. Lastly, studies of glyburide, an anti-diabetic medication, have shown an off-target anti-inflammatory effect specific for the NLRP3 inflammasome, which has been implicated in AD development. Therefore, a series of glyburide analogs were synthesized and characterized. One analog was able to successfully inhibit the NLRP3 inflammasome and reduce IL-1ß expression without affecting blood glucose. In vivo studies demonstrated an ability to prevent or ameliorate adverse inflammation-related outcomes in murine inflammatory models. Altogether, these investigations have yielded three novel series of compounds, all capable of modifying Alzheimer’s disease pathology. These results warrant future investigations into the development, optimization, and characterization of these analogs as potential treatments for Alzheimer’s disease.

Studies of widely diverse species of a protein are a powerful tool to gain information on the structure and function of the protein. We investigated the response of human, pig, shark and killifish cystic fibrosis trans-membrane conductance regulator (CFTR) to specific inhibitors of the channel: CFTRinh-172, GlyH-101, and glibenclamide. In several expression systems, including isolated perfusions of the rectal gland, primary cell cultures of rectal gland tubules and oocyte expression, we observed fundamental differences in the sensitivity to inhibition by these CFTR blockers. We used primarily two-electrode voltage clamping of cRNA microinjected Xenopus laevis oocytes. In oocyte studies, shark CFTR was insensitive to CFTRinh-172 (maximum inhibition 8 ± 1.4% at 20µM), pCFTR was insensitive to Glibenclamide (maximum inhibition 12.8 ± 4.2% at 200µM), and all species were sensitive to GlyH-101 (maximum inhibition with pCFTR of 80.2 ± 3.6% at 20µM). Shark CFTR was completely insensitive to inhibition by CFTRinh-172 in short circuit current experiments (2.5 ± 0.15 % inhibition of chloride secretion) compared to inhibition with GlyH-101 (56.5 ± 6.56 % inhibition of chloride secretion). Perfusion studies confirmed these results. These experiments demonstrate a profound difference in the sensitivity of different CFTR species to inhibition by CFTR blockers. However, the amino acid residues that have been proposed by site directed mutagenesis studies to be responsible for inhibitor binding are uniformly conserved in all four isoforms studied. Therefore, the differences cannot be explained by simply targeting one amino acid for site-directed mutagenesis. Rather, the potency of the inhibitory actions of CFTRinh-172, Gly-H101 and glibenclamide on the CFTR molecule is dictated by the local environment and the three dimensional structure of residues that form the vestibule and the chloride pore.