Biology subjects

Regnault, T. R.

Publications and source records attributed to Regnault, T. R..

3 recordsLinked to original sources

bioRxiv2022

The impact of hyperglycemia upon BeWo trophoblast cell metabolic function: A multi-OMICS and functional metabolic analysis

Pre-existing and gestationally-developed diabetes mellitus have been linked with impaired metabolic function in placental villous trophoblast cells, that is thought to underlie the development of metabolic diseases early in the lives of the exposed offspring. Previous research using placental cell lines and ex vivo trophoblast preparations have highlighted hyperglycemia as an important independent regulator of placental function. However, it is poorly understood if hyperglycemia directly influences aspects of placental metabolic function, including nutrient storage and mitochondrial respiration, that have been found to be impaired in diabetic placentae. Therefore, the current study examined metabolic and mitochondrial function as well as nutrient storage in both undifferentiated cytotrophoblast and differentiated syncytiotrophoblast BeWo cells cultured under hyperglycemia conditions (25 mM glucose) for 72 hours to further characterize the direct impacts of placental hyperglycemic exposure. Hyperglycemic-exposed BeWo trophoblasts displayed increased triglyceride and glycogen nutrient stores. However, specific functional readouts of metabolic enzyme activity and mitochondrial oxidative respiratory activity were not altered. We speculated that increased glycogen content may reduce free glucose available for oxidation and subsequently protect trophoblast cells from mitochondrial damage during acute high glucose exposures. To further characterize the impacts of independent hyperglycemia, the current study subsequently utilized a multi-omics approach and evaluated the transcriptomic and metabolomic signatures of BeWo cytotrophoblasts. Hyperglycemic exposure was associated with an altered transcriptomic profile (e.g. increased expression of ACSL1 (+1.36 fold-change (FC), HSD11B2 (+1.35 FC), and RPS6KA5 (+1.32 FC)), and metabolome profile (e.g. increased levels lactate (+2.72 FC), malonate (+3.74 FC), and riboflavin (+3.68 FC)) in BeWo cytotrophoblasts that further highlighted trophoblast metabolic function is modulated independently by hyperglycemia. Overall, these results demonstrate that hyperglycemia is an important independent regulator of key areas of placental metabolic function and nutrient storage, and these data continue to expand our knowledge on the mechanisms governing the development of placental dysfunction.

developmental biology↗

bioRxiv2021

In vivo magnetic resonance spectroscopy of hyperpolarized pyruvate in a male guinea pig model of life-long Western diet consumption and non-alcoholic fatty liver disease development

BACKGROUNDAlterations in glycolysis and oxidative pathways are central to the increasing incidence of non-alcoholic fatty liver disease (NAFLD), highlighting a need for in vivo, non-invasive technologies to understand the development of hepatic metabolic aberrations in lean NAFLD. PURPOSE/HYPOTHESISTo use hyperpolarized magnetic resonance spectroscopy (MRS) and proton density fat fraction (PDFF) MRI techniques to investigate effects of a chronic, life-long exposure to the Western Diet (WD) in a model of NAFLD and identify cellular metabolite changes and correlations related to enzyme activity. It is hypothesized that exposure to the WD will result in NAFLD in association with altered pyruvate metabolism. STUDY TYPEProspective POPULATION/SUBJECTS/PHANTOM/SPECIMEN/ANIMAL MODEL: 28 male guinea pigs were weaned onto a control diet or WD. FIELD STRENGTH/SEQUENCE3T; T1, T2, IDEAL, broadband PRESS MRS. ASSESSMENTMedian PDFF was calculated in the liver and hind limbs. [1-13C]pyruvate dynamic MRS in the liver was quantified by the time to peak (TTP), calculated as the time from pyruvate peak to metabolite peak. After a recovery period, animals were euthanized, and tissue was analyzed for lipid and cholesterol concentration and enzyme level and activity. STATISTICAL TESTSUnpaired Students t-tests were used to determine differences in measurements between the two diet groups. The Pearson correlation coefficient was calculated to determine correlations between measurements. RESULTSLife-long WD consumption resulted in significantly higher liver PDFF correlated with elevated triglyceride content in the liver. The WD group exhibited a decreased TTP for lactate production, and ex vivo analysis highlighted increased liver lactate dehydrogenase (LDH) activity. DATA CONCLUSION: PDFF MRI results suggest differential fat deposition patterns occurring in animals fed a life-long WD, corresponding with increased liver triglyceride levels characteristic of lean NAFLD. The decreased liver lactate TTP and increased ex vivo LDH activity suggest lipid accumulation occurs in association with a shift from oxidative metabolism to anaerobic glycolytic metabolism in WD livers.

biophysics↗

bioRxiv2020

Time mating guinea pigs by monitoring changes to the vaginal membrane throughout the estrus cycle and with ultrasound confirmation

Guinea pig development in utero is more similar to humans than any other rodent species. As such, their importance to reproductive studies is evident, particularly those studies focused on therapeutic interventions to improve human pregnancy outcome. Tracking the guinea pig estrus cycle is imperative to ensuring appropriately timed mating and can be performed by monitoring the guinea pig vaginal membrane. Here, we describe, and provide picture representation, of changes to the guinea pig vaginal membrane throughout the estrus cycle. Utilization of this monitoring enabled a 100% pregnancy success rate on the first mating attempt in a cohort of five guinea pigs. This approach, along with early pregnancy ultrasounds as a secondary method to confirm pregnancy, offers a cost effective and reliable approach to timed-mating in the guinea pig.

physiology↗