Diet ModulatedThyroid Hormone Signaling Influences Region Specific Gene Expression in the Mouse Brain

Authors:

Lucy Ponce, Daniel Hochbaum

Date Created:

2025-01-01

Course Title:

Professor:

Not specified

About Paper:

Thyroid hormone (TH) is a key regulator of metabolism and Among hippocampus samples, Robo3 expression showed a dose- behavior, yet the mechanisms by which dietary inputs affect dependent increase across 0.15 ppm Se diets as iodine increased tissue specific hormone signaling remain unclear. Prior studies from 0 ppm (X I) to 0.2 ppm and 1 ppm. In contrast, Robo3 have shown that the active thyroid hormone triiodothyronine (T3) expression in M2 varied more widely across conditions. While Hr influences gene regulation within the cerebral cortex, resulting inand Cyp11a1 were also measured, they showed diverse expression modified exploratory and risk-related behaviors, with sex-specific levels across dietary groups, perhaps due to lower sensitivity to T3 effects. In my lab, we examined how selenium and iodine, two levels. essential dietary components of the thyroid hormone system, alter TH responsive gene expression in male mice. This data suggests that Robo3 may serve as a sensitive transcriptional marker of TH signaling within the hippocampus, We collected hippocampus and secondary motor cortex (M2) with the effect of iodine on expression modulated by selenium. tissue from mice maintained on diets varying in selenium (0.15- This contributes to our understanding of how nutrition and 1 ppm) and iodine (0.2-2 ppm), and performed RNA extraction, endocrine signaling interact in the brain and primes links between cDNA synthesis, and qPCR analysis for T3-sensitive genes, which molecular changes, behavior, and inflammation. Next, we plan includes Robo3, Hr, and Cyp11a1. Expression values were to assess how these dietary conditions influence exploratory and normalized to Gapdh. Liver samples were also analyzed for Dio1, anxiety related behavior using a light-dark box assay, providing a an enzyme that converts inactive T4 to active T3, responsive to behavioral correlation to differences in gene regulation observed circulating T3 levels. across brain regions. PFAS Composition and Distribution in Residential Soil and Dust Following Wildfires in Los Angeles Aryenne Ysabelle Rodrigo, Yumin Zhu, Elsie Sunderland, Zhiji Hu Harvard College | Cabot House | Environmental Science and Engineering | 2027 Per- and polyfluoroalkyl substances (PFAS) are a class of were attempted to be identified and quantified using an ultra- widespread anthropogenic chemicals in the environment that can high performance liquid chromatograph coupled with ultra-high deposit in the soil and dust. PFAS are historically used in resolution Orbitrap mass spectrometer. The preliminary results some firefighting foams for their heat resistance and surfactant indicatethatthemeantotalconcentrationofPFASinthedust(1728 properties. However, the effects of the wildfire and fire ▯ 3530 ng/g) is much higher than that in the soil (429 ▯ 1197 suppression activities on PFAS fingerprints are not well explored, ng/g), despite fewer dust samples. Trifluoroacetic acid (TFA), a especially with increasingly frequent and intense wildfires in the short-chain PFAS of emerging concern, showed increasing mean United States. In this study, we sampled 38 households across concentrations with proximity to burn areas, reaching up to 2489 two burn zones impacted by the recent Los Angeles wildfires in ▯ 5006 ng/g in dust and 162 ▯ 271 ng/g in soil in the burn zone. 2024. A total of 33 dust and 41 soil samples were collected. These findings suggest the need for further research on wildfire- At each sampling site, occupancy status, distance from the driven PFAS mobilization and potential human exposure. PFAS burn zone, sampling location within the residence, and cleaning compositional differences between locations and key contributing status were recorded. 75 target PFAS or fluorinated compounds factors are being analyzed.

Abstract:

Thyroid hormone (TH) is a key regulator of metabolism and Among hippocampus samples, Robo3 expression showed a dose- behavior, yet the mechanisms by which dietary inputs affect dependent increase across 0.15 ppm Se diets as iodine increased tissue specific hormone signaling remain unclear. Prior studies from 0 ppm (X I) to 0.2 ppm and 1 ppm. In contrast, Robo3 have shown that the active thyroid hormone triiodothyronine (T3) expression in M2 varied more widely across conditions. While Hr influences gene regulation within the cerebral cortex, resulting inand Cyp11a1 were also measured, they showed diverse expression modified exploratory and risk-related behaviors, with sex-specific levels across dietary groups, perhaps due to lower sensitivity to T3 effects. In my lab, we examined how selenium and iodine, two levels. essential dietary components of the thyroid hormone system, alter TH responsive gene expression in male mice. This data suggests that Robo3 may serve as a sensitive transcriptional marker of TH signaling within the hippocampus, We collected hippocampus and secondary motor cortex (M2) with the effect of iodine on expression modulated by selenium. tissue from mice maintained on diets varying in selenium (0.15- This contributes to our understanding of how nutrition and 1 ppm) and iodine (0.2-2 ppm), and performed RNA extraction, endocrine signaling interact in the brain and primes links between cDNA synthesis, and qPCR analysis for T3-sensitive genes, which molecular changes, behavior, and inflammation. Next, we plan includes Robo3, Hr, and Cyp11a1. Expression values were to assess how these dietary conditions influence exploratory and normalized to Gapdh. Liver samples were also analyzed for Dio1, anxiety related behavior using a light-dark box assay, providing a an enzyme that converts inactive T4 to active T3, responsive to behavioral correlation to differences in gene regulation observed circulating T3 levels. across brain regions. PFAS Composition and Distribution in Residential Soil and Dust Following Wildfires in Los Angeles Aryenne Ysabelle Rodrigo, Yumin Zhu, Elsie Sunderland, Zhiji Hu Harvard College | Cabot House | Environmental Science and Engineering | 2027 Per- and polyfluoroalkyl substances (PFAS) are a class of were attempted to be identified and quantified using an ultra- widespread anthropogenic chemicals in the environment that can high performance liquid chromatograph coupled with ultra-high deposit in the soil and dust. PFAS are historically used in resolution Orbitrap mass spectrometer. The preliminary results some firefighting foams for their heat resistance and surfactant indicatethatthemeantotalconcentrationofPFASinthedust(1728 properties. However, the effects of the wildfire and fire ▯ 3530 ng/g) is much higher than that in the soil (429 ▯ 1197 suppression activities on PFAS fingerprints are not well explored, ng/g), despite fewer dust samples. Trifluoroacetic acid (TFA), a especially with increasingly frequent and intense wildfires in the short-chain PFAS of emerging concern, showed increasing mean United States. In this study, we sampled 38 households across concentrations with proximity to burn areas, reaching up to 2489 two burn zones impacted by the recent Los Angeles wildfires in ▯ 5006 ng/g in dust and 162 ▯ 271 ng/g in soil in the burn zone. 2024. A total of 33 dust and 41 soil samples were collected. These findings suggest the need for further research on wildfire- At each sampling site, occupancy status, distance from the driven PFAS mobilization and potential human exposure. PFAS burn zone, sampling location within the residence, and cleaning compositional differences between locations and key contributing status were recorded. 75 target PFAS or fluorinated compounds factors are being analyzed.

Source:

Harvard / Harvard College | Adams House | Biomedical Engineering | 2028 / 2025

Topics:

pfas, expression, ppm, hormone, gene, acros, soil, dust, wildfire, signaling, sample, robo3

Co-authors:

@lucyponce359 , @danielhochbaum360