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Biology subjects

Riojas, A. M.

Publications and source records attributed to Riojas, A. M..

3 recordsLinked to original sources

Perinatal maternal undernutrition in baboons modulates hepatic mitochondrial function but not metabolites in aging offspring.

We previously demonstrated in baboons that maternal undernutrition (MUN), achieved by 70 % of control nutrition, impairs fetal liver function, but long-term changes associated with aging in this model remain unexplored. Here, we assessed clinical phenotypes of liver function, mitochondrial bioenergetics, and protein abundance in adult male and female baboons exposed to MUN during pregnancy and lactation and their control counterparts. Plasma liver enzymes were assessed enzymatically. Liver glycogen, choline, and lipid concentrations were quantified by magnetic resonance spectroscopy. Mitochondrial respiration in primary hepatocytes under standard culture conditions and in response to metabolic (1 mM glucose) and oxidative (100 {micro}M H2O2) stress were assessed with Seahorse XFe96. Hepatocyte mitochondrial membrane potential (MMP) and protein abundance were determined by tetramethylrhodamine ethyl ester staining and immunoblotting, respectively. Liver enzymes and metabolite concentrations were largely unaffected by MUN, except for higher aspartate aminotransferase levels in MUN offspring when male and female data were combined. Oxygen consumption rate, extracellular acidification rate, and MMP were significantly higher in male MUN offspring relative to control animals under standard culture. However, in females, cellular respiration was similar in control and MUN offspring. In response to low glucose challenge, only control male hepatocytes were resistant to low glucose-stimulated increase in basal and ATP-linked respiration. H2O2 did not affect hepatocyte mitochondrial respiration. Protein markers of mitochondrial respiratory chain subunits, biogenesis, dynamics, and antioxidant enzymes were unchanged. Male-specific increases in mitochondrial bioenergetics in MUN offspring may be associated with increased energy demand in these animals. The similarity in systemic liver parameters suggests that changes in hepatocyte bioenergetics capacity precede detectable circulatory hepatic defects in MUN offspring and that the mitochondria may be an orchestrator of liver programming outcome.

physiology↗

Maternal Under-Nutrition During Pregnancy Alters the Molecular Response to Over-Nutrition in Multiple Organs and Tissues in Juvenile Offspring

Previous studies suggest that mismatch between fetal and postnatal nutrition predisposes individuals to metabolic diseases. We examined whether NHP juvenile offspring of pregnancies with maternal undernutrition (MUN) had altered response to a high-fat, high-carbohydrate diet plus sugar drink challenge (HFCS) compared with controls (CON). Pregnant baboons were fed ad libitum (CON) or 30% calorie reduction from 0.16 gestation through lactation, and weaned offspring fed chow diet ad libitum. Offspring of MUN were growth restricted at birth. At [~]4.5y offspring received a 7-week HFCS challenge. Baseline and HFCS gene expression in liver, omental fat, and skeletal muscle, liver glycogen content, and fat cell size were quantified. MUN offspring had lower BMI and liver glycogen compared with CON. Pathway analysis showed differences for skeletal muscle and liver, including hepatic splicing and unfolded protein response. MUN offspring consumed more sugar drink than CON. After HFCS, MUN BMIs were similar to CON. Liver showed coordinated response to HFCS in CON but not MUN. Pathway and liver glycogen differences between MUN and CON at baseline indicate in utero programming persists in MUN juveniles. MUN catchup growth during HFCS suggests increased risk of obesity, diabetes, and cardiovascular disease. Greater sugar drink consumption in MUN demonstrates altered appetitive drive due to programming. Differences in blood leptin concentrations, omental adipocyte cell size, liver glycogen content, and tissue-specific molecular response to HFCS challenge suggest MUN significantly impacts juvenile offspring ability to manage an energy rich diet. O_FIG O_LINKSMALLFIG WIDTH=172 HEIGHT=200 SRC="FIGDIR/small/548121v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@b15085org.highwire.dtl.DTLVardef@11d4c1dorg.highwire.dtl.DTLVardef@704209org.highwire.dtl.DTLVardef@1ff9791_HPS_FORMAT_FIGEXP M_FIG C_FIG

systems biology↗

Blood pressure and the kidney cortex transcriptome response to high sodium diet challenge in female nonhuman primates

Blood pressure (BP) is influenced by genetic variation and sodium intake. Ninety percent of Americans consume more than the AHA recommended amount of sodium. Studies on the impact of genetic variation and sodium intake on BP in nonhuman primates (NHP) to date have focused on males. We hypothesized that variation in renal transcriptional networks correlate with BP response to high dietary sodium in female baboons. Sodium-naive female baboons (n=7) were fed a low-sodium (LS) diet for 6 weeks followed by a high sodium (HS) diet for 6 weeks. Sodium intake, serum 17 betaestradiol, and ultrasound-guided kidney biopsies for RNA-Seq BP were collected at the end of each diet. BP was continuously measured for 64-hour periods throughout the study by implantable telemetry devices. On the LS diet, Na+ intake and serum 17 beta-estradiol concentration correlated with BP. Kidney transcriptomes differed by diet; analysis by unbiased weighted gene co-expression network analysis revealed modules of genes correlated with BP on the HS diet. Cell type composition of renal biopsies was consistent among all animals for both diets. Network analysis of module genes showed causal networks linking hormone receptors, proliferation and differentiation, methylation, hypoxia, insulin and lipid regulation, and inflammation as regulators underlying variation in BP on the HS diet. Our results show variation in BP correlated with novel kidney gene networks with master regulators PPARG and MYC in female baboons on a HS diet. Identification of mechanisms underlying regulators that influence BP will inform better therapies towards greater precision medicine for women.

genomics↗