Project description:Molecular mechanisms triggered by high dietary beta-carotene (BC) intake in liver are largely unknown. We performed microarray gene expression analysis on liver tissue of BC supplemented beta-carotene 15,150-monooxygenase 1 knockout (Bcmo1-/-) mice, which are—like humans—able to accumulate BC. This was compared with litter mates being wild-type (Bcmo1+/+) mice, and we analysed both males and females, as we previously showed that in lung tissue we observed opposite gene regulation between males and females (Van Helden et al., CMLS 2011).
Project description:Nutritional effects by beta-carotene versus control in lung, inguinal white adipose tissue, and liver in males and females of control wildtype mice versus BCMO/BCO1 knockout mice
Project description:Molecular mechanisms triggered by high dietary beta-carotene (BC) intake in lung are largely unknown. We performed microarray gene expression analysis on lung tissue of BC supplemented beta-carotene 15,150-monooxygenase 1 knockout (Bcmo1-/-) mice, which are—like humans—able to accumulate BC. Our main observation was that the genes were regulated in an opposite direction in male and female Bcmo1-/- mice by BC. The steroid biosynthetic pathway was overrepresented in BC-supplemented male Bcmo1-/- mice. Testosterone levels were higher after BC supplementation only in Bcmo1-/- mice, which had, unlike wild-type (Bcmo1+/+) mice, large variations. We hypothesize that BC possibly affects hormone synthesis or metabolism. Since sex hormones influence lung cancer risk, these data might contribute to an explanation for the previously found increased lung cancer risk after BC supplementation (ATBC and CARET studies). Moreover, effects of BC may depend on the presence of frequent human BCMO1 polymorphisms, since these effects were not found in wild-type mice.
Project description:Liver dysfunction including coagulopathy is a prominent feature of proteinenergy malnutrition. To identify mechanisms underlying malnutrition-associated coagulopathy, we administered low-protein low-fat diet to lactating dams and examined hepatic transcription and plasma coagulation parameters in young adult weanlings. Malnutrition impairs growth and liver synthetic function more severely in males versus females. Malnourished males are coagulopathic and exhibit decreased hepatocyte peroxisomes, FXR agonist bile acids, FXR binding on Fga and F11 gene regulatory elements, and coagulation factor synthesis. These effects are absent in female mice, which have low baseline levels of PPARα, suggesting that nutrient-sensing nuclear receptors regulate coagulation factor synthesis in response to host nutritional status in a sex-specific manner.
Project description:We studied a group of melanoma patients treated with neoadjuvant BRAF/MEK-targeted therapy (NCT02231775, n=51), and observed significantly higher rates of major pathologic response (MPR= <10% viable tumor at resection) and improved recurrence-free survival (RFS) in females versus males (MPR-66% versus 14%, p=0.001; RFS-64% versus 32% at 2 years, p=0.021). Findings were validated in a several additional cohorts 2-4 patients with unresectable metastatic melanoma treated with BRAF and/or MEK-targeted therapy (n=664 patients in total), demonstrating improved progression-free survival (PFS) and overall survival (OS) in females versus males in several of these studies. Studies in pre-clinical models demonstrated significantly impaired anti-tumor activity in male versus female BRAF/MEK-treated mice (p=0.006), with significantly higher expression of androgen receptor (AR) in tumors of male and female BRAF/MEK-treated mice versus control (p=0.0006 and 0.0025). Pharmacologic inhibition of AR signaling improved responses to BRAF/MEK-targeted therapy in male and female mice (p=0.018 and p=0.003), whereas induction of AR signaling (via testosterone administration) was associated with significantly impaired response to BRAF/MEK-targeted therapy in males and females (p=0.021 and p<0.0001).
Project description:Atherosclerosis is characterized by the pathological accumulation of cholesterol-laden macrophages in the arterial wall. Atherosclerosis is also the main underlying cause of cardiovascular diseases (CVDs), and its development is largely driven by elevated plasma cholesterol. Strong epidemiological data find an inverse association between plasma β-carotene with atherosclerosis, and we recently showed that β-carotene oxygenase 1 (BCO1) activity, responsible for β-carotene cleavage to vitamin A, is associated with reduced plasma cholesterol in humans and mice. In this study, we explore whether intact β-carotene or vitamin A affect atherosclerosis progression in the atheroprone low-density lipoprotein receptor (LDLR) - deficient mice. In comparison to control-fed Ldlr-/- mice, β-carotene-supplemented mice showed reduced atherosclerotic lesion size at the level of the aortic root and plasma cholesterol levels (P = 0.0003). These changes were absent in Ldlr-/-/Bco1-/- mice, despite accumulating β-carotene in plasma and atherosclerotic lesions. We discarded the implication of myeloid BCO1 in the development of atherosclerosis by performing bone marrow transplant experiments. Lipid production assays found that retinoic acid, the active form of vitamin A, reduced the secretion of newly synthetized triglyceride and cholesteryl ester in cell culture and mice. Overall, our findings provide insights into the role of BCO1 activity and vitamin A in atherosclerosis progression through the regulation of hepatic lipid metabolism.
Project description:In this study, we subjected male and female mice to bleomycin-induced lung injury for 14-days. Bronchoalveolar lavage cells were isolated and subjected to RNA-sequencing. Four groups were compared. Saline-Males and females and bleomycin-males and females.
Project description:Soybeans (Glycine max) were genetically modified using a gene gun to produce beta-carotene, which is not normally found in the species. beta-carotene is produced in the chloroplast in which it competes with chlorophyl for production. A proteomics analysis was performed to determine the effects of the transgene on seed protein content.
