Biology subjects

Boer, P. A.

Publications and source records attributed to Boer, P. A..

8 recordsLinked to original sources

bioRxiv2026

Early impact of gestational protein restriction on nephrogenesis in male mouse offspring: Role of Autophagy and Apoptosis Mechanisms

BackgroundMaternal protein restriction results in a 28% reduction in nephrogenic cells and nephron units in rodent offspring by the 17th day of gestation compared to adequate protein intake. AimsThe present study investigates the association between growth factor expression and some developmental pathways that contribute to nephron reduction during embryonic and fetal development. Experimental DesignPregnant C57BL/6-Tg and C57BL/6J mice were assigned to either normal protein intake (NP-17%) or low protein intake (LP-6%) groups. Body weight of male offspring and kidney growth factor expression were assessed on gestation days (GD) 14 and 18. ResultsOn GD 14, LP pups exhibited a 4% higher body mass (0.1035 g) compared to NP pups (0.0995 g, p = 0.005). By GD 18, LP pups demonstrated a 4% decrease in body mass (0.939 g, p = 0.03) and a 10% increase in the number of cells per metanephric cap area. Three genes (Csf2, Il1b, Il2) were downregulated, while seven genes (Bmp2, Csf3, Fgf8, Gdnf, Bmp7, Fgf3, Ntf3) were upregulated. By GD 14, phagophores and autophagosomes in the ureteric bud increased by 197%, with further increases observed by GD 18. Bcl-2 expression increased significantly in ureteric bud cells, and mTOR activity was elevated by GD 18. ConclusionEarly gestational protein restriction modifies renal growth factor gene expression, influencing cell proliferation and autophagy, and may contribute to reduced nephron numbers by the 18th day of gestation. HIGHLIGHTSO_LIThis study examines the effects of a low-protein diet during pregnancy in mice and demonstrates a significant reduction in embryo-fetal body weight between gestational days 14 and 18. C_LIO_LIProtein restriction induces a distinct cellular pattern in the mesonephros, with a 21% increase in CAP cells at gestational day 14 (GD14), followed by a decrease by gestational day 18 (GD18) compared to offspring from mothers on a normal protein diet. C_LIO_LIAdditionally, increased expression levels of key growth factors essential for kidney development were observed at GD 14, comparing LP with NP intake during pregnancy. C_LIO_LISeven genes were upregulated (Gdnf, Bmp2, Bmp7, Tgf, Fgf8, Fgf3, Csf3, Ntf3), while three genes were downregulated (Csf2, Il1b, Il2). C_LIO_LIOverall, these findings indicate that gene regulation, autophagy, and mTOR signaling mechanisms significantly influence nephron numbers in response to gestational protein restriction beyond the 18th day of gestation. C_LI

developmental biology↗

bioRxiv2024

Enriched environmental intervention mitigates hippocampal cellularity and behavioral disorders in maternal protein-restricted male rat offspring

BackgroundGestational protein intake restriction induces long-lasting harmful outcomes in the offsprings organs and systems. AimsThis study sought to evaluate the effects of protein restriction during pregnancy and breastfeeding in 42-day-old male offspring on the structure of the hippocampus, behavior tests related to memory and emotions, and the influence of an enriched environment on these parameters. Results and DiscussionThe current study demonstrated that maternal protein restriction during neural development causes crucial morphological changes in the hippocampus, making the LP offspring vulnerable to specific neural disorders in adulthood. In addition, it supports the selfish brain theory, a paradigm that postulates the brain maintains its mass selfishly by reallocating resources from other body parts when faced with nutritional stress. However, the hippocampus cellularity pattern was profoundly altered, significantly reducing the number of neurons after the breastfeeding period. This may expand the understanding of nutritional stress affecting the brain areas constitution and its supposed effects on posterior behavioral disorders. Here, reciprocal data was observed between brain masses, changes in the hippocampus cell pattern, and decreased body mass in the LP progeny. In conclusion it was demonstrated that neuronal composition and structure profoundly modified by dietary restriction are surprisingly restored from primordial cells by exposure to the enriched environment. In addition, we must emphasize that although we have observed a significant reduction in the number of neurons after gestational and breastfeeding periods, we demonstrated for the first time a substantial reduction in the fear-reflecting behavior, which an enriched environment exposure may revert. The enriched environment also significantly modified the discrimination ratio, increasing the ability of both progenies to discriminate between novel and familiar objects in a short time associated with reverse abnormal hippocampus cell patterns. These findings underscore the potential for environmental interventions to mitigate the effects of early=life nutritional stress on brain development and behavior.

animal behavior and cognition↗

bioRxiv2022

Impact of maternal protein restriction on hypoxia-inducible factor (HIF) expression in male fetal kidney development

BackgroundThe kidney ontogenesis is the most structurally affected by gestational protein restriction, reducing close to 30% of their functional units. The reduced nephron number is predictive of hypertension and cardiovascular dysfunctions generally observed in the adult age of most fetal programming models. We demonstrate HIF-1 predicts molecular pathway changes may be associated with the decreased nephron numbers in the 17 gestational days (17GD) low protein (LP) intake male fetal kidney compared to regular protein (NP) progeny intake. Here, we evaluated the predicted targets and related pathways in the fetal kidneys of 17-GD LP offspring to elucidate the molecular modulations during nephrogenesis. MethodsPregnant Wistar rats were allocated into two groups: NP (regular protein diet -17%) or LP (diet-6%). Taking into account miRNA transcriptome sequencing previous study (miRNA-Seq) in 17-GD male offspring kidneys using previously described methods, was investigated predicted target genes and proteins, in particular, related to HIF-1 pathway by RT-qPCR and immunohistochemistry. Results and conclusionsThe current study data supported that nephron onset impairment in the 17-DG fetuss kidney, programmed by gestational low-protein intake, is, at least in part, related to alterations in the HIF-1 signaling pathway. Factors that facilitate the transposition of HIF-1 to the mesenchymal cells nucleus, such as NOS, Ep300, and HSP90, may have an essential role in this regulatory process. This alteration leads to the inhibition of adaptive responses to the adverse environment, secondary to an increase in ungraded HIF-1, possibly associated with a reduction in the transcription factor elF-4 and proteins of their respective signaling pathways. Consequently, we may suggest an early maturation process of renal cells, inhibition of nephron progenitor cell division, and reduction of renal functional units in the offspring of rats submitted to severe gestational protein restriction.

developmental biology↗

bioRxiv2021

Precocious hippocampal structural and functional changes in gestational protein-restricted male elderly offspring: an Alzheimer-simile disease model?

BackgroundMaternal undernutrition has been associated with psychiatric and neurological disorders characterized by learning and memory impairment. Considering the lack of evidence for this, we aimed to analyze the effects of gestational protein restriction on learning and memory function later in life. This research associates behavioral findings with hippocampal cell numbers and protein content related to neurodegenerative brain disease. MethodsExperiments were conducted in animals subjected to a low-protein (LP, 6% casein) or regular-protein (NP, 17% casein) diet throughout their pregnancy. Behavioral tests, isolated hippocampal isotropic fractionator cell studies, immunoblotting, and survival lifetime tests were performed. The results confirmed that the birthweight of LP male pups significantly reduced relative to NP male pups and that hippocampal mass increased in 88-week-old LP compared to age-matched NP offspring. We used the Morris water maze proximity measure, which is the sum of 10 distances each second between rat position and location of a hidden platform target, as a suitable test for assessing age-related learning or memory impairment in aged offspring. ResultsThe results showed an increased proximity measure in 87-week-old LP rats (52.6 x 104 {+/-} 10.3 x 104 mm) as compared to NP rats (47.0 x 104 {+/-} 10.6 x 103 mm, p = 0.0007). In addition, LP rats exhibited anxiety-like behaviors compared to NP rats at 48 and 86 weeks of life. Additionally, the estimated neuron number was unaltered in LP rats; however, glial and other cell numbers increased in LP compared to NP rats. Here, we showed unprecedented hippocampal deposition of brain-derived neurotrophic factor, {beta}-amyloid peptide (A{beta}), and tau protein in 88-week-old LP compared to age-matched NP offspring. To date, no predicted studies showed changes in hippocampal neuron and glial cell numbers in maternal protein-restricted elderly offspring. The current data suggest that maternal protein restriction has a high impact on lifespan and brain structure, and function. Conclusionthe gestational protein restriction may accelerate hippocampal function loss, impacting learning/memory performance, and supposedly developing diseases similar to Alzheimers disease (AD) in elderly offspring. Thus, we propose that maternal protein restriction could be a probable, elegant, and novel method for constructing an AD-like model in adult male offspring.

developmental biology↗

bioRxiv2020

Impact of gestational low-protein intake on embryonic kidney microRNA expression and in the nephron progenitor cells of the male offspring fetus

Authors have demonstrated that gestational low-protein (LP) intake offspring showed a lower birth weight, reduced nephrons numbers and renal salt excretion, chronic renal failure, and arterial hypertension development when compared to normal (NP) protein intake group in adult life. The current study was aimed to evaluate the miRNAs and predicted gene expression patterns in the fetal kidney at 17 days of gestational (17-DG) protein-restricted male offspring (LP) in an attempt to elucidate the possible molecular pathways and disorders involved in renal cell proliferation and differentiation during kidney development. By NGS and RT-qPCR were identified, 44 differentially expressed miRNAs, which 19 miRNA were up- and 25 downregulated in LP compared to NP offspring metanephros. Among the top 10 deregulated miRNAs, the study selected 7 miRNAs which its biological targets were related to proliferation, differentiation, and cellular apoptosis processes. As could be seen below, both miRNA-Seq and TaqMan data analysis have shown a consistent change of miRNA expression in LP animals relative to control NP age-matched animals. By immunofluorescence, the LP fetus showed a significant 28% reduction of Six-2 labeled cells when compared to NP offspring associated with a reduced percentage of cell number and c-Myc metanephogenic cap and ureter bud immunostained cells in LP relative to NP offspring. Additionally, the Ki-67 labeled area in CM was 48% lesser in LP compared to NP age-matched fetus. On the other hand, in LP, the CM and UB {beta}-catenin marked area were 154 and 85% raised, respectively. Mtor immunoreactivity was also significantly higher in LP CM (139%) and UB (104%) compared to the NP fetus. In the LP offspring, the TGF{beta}-1 in UBs cells staining increased (about 30%). In contrast, Zeb1 metanephros-stained, located in the CM nuclei cells, enhanced 30% in LP and Zeb2 immunofluorescence, although present in whole metanephros structures, was similar in both experimental groups. In conclusion, the present study demonstrates that the miRNAs, mRNAs, and proteins are modified in LP animals with 17 DGs leading to the reduction of the reciprocal induction between CM and UB, and hence the number of nephrons. These findings will facilitate new functional approaches and further studies to elucidate the regulatory mechanisms involved in the processes of proliferation, differentiation, and apoptosis that occurs during renal development.

developmental biology↗

bioRxiv2018

miRNAs, target genes expression and morphological analysis on the heart in gestational protein-restricted offspring

BACKGROUNDGestational protein restriction was associated with low birth weight, hypertension and higher prevalence of cardiac disorders in adults. Several mechanisms, including epigenetics, could be related with the cardiovascular phenotype on protein-restricted offspring. Thus, we investigated the morphological cardiac effects of gestational protein restriction and left ventricle miRNAs and target genes expression pattern in both 12-day and 16-week old gestational protein-restricted male offspring.\n\nMETHODSPregnant Wistar rats were allocated into two groups, according to protein supply during pregnancy: NP (normal protein diet-17%) or LP (low protein diet - 6%). The study evaluates the effects of maternal protein restriction on food consumption and body weight of both pregnant dams and offspring, systolic blood pressure in 16-wk old offspring and on cardiac morphometric and molecular parameters in both 12-d and 16-wk old offspring.\n\nRESULTSDams on the gestational protein-restricted diet had lower body weight gain and higher food intake. Gestational protein-restricted offspring had low birth weight, followed by rapidly body weight recovery, hypertension, and increased myocytes crosssectional area and collagen fraction at 16-week old age. At 12-days old, miR-184, miR-192, miR-376c, miR-380-3p, miR-380-5p, miR-451, and miR-582-3p had increased expression, and miR-547 and miR-743 a had decreased expression in the gestational protein-restricted left ventricle. At 16-week old, let-7b, miR-125a-3p, miR-142-3p, miR-182 and miR-188-5p had increased expression and let-7g, miR-107, miR-127, miR-181a, miR-181c, miR-184, miR-324-5p, miR-383, miR-423-5p and miR-484 had decreased expression in gestational protein-restricted left ventricle. Target predicted gene expression analysis shown higher expression of Dnmt3a, Oxct1, Rictor and Trps1 and lower expression of Bbs1 and Calml3 in 12-day old protein-restricted offspring. 16-week old protein-restricted offspring had higher expression of Adrbk1, Bbs1, Dnmt3a, Gpr22, Inppl1, and Oxct1 genes.\n\nCONCLUSIONGestational protein restriction leads to offspring low birth weight, increased systolic blood pressure and morphological heart alterations that could be related to early heart miRNA expression changes that perpetuate into adulthood and which are associated with the regulation of essential genes involved in cardiovascular development, heart morphology, function, and metabolism.

developmental biology↗

bioRxiv2018

Effect of intracerebroventricular epinephrine microinjection on blood pressure and urinary sodium handling in gestational protein-restricted rat adult male offspring

BackgroundIn this study, we hypothesized that blunting of the natriuresis response to intracerebroventricularly (i.c.v.) microinjected adrenergic agonists are involved in the development of hypertension in maternal low-protein (LP) intake offspring. Methods. Stainless steel cannula was stereotaxically implanted into the right lateral ventricle, by use of techniques reported elsewhere and after that, was evaluated the effect of i.c.v. injection of adrenergic agonists, at increasing concentrations, and of 1 and 2-adrenoceptor antagonists on blood pressure and urinary sodium handling in LP offspring relative to age-matched, normal (NP) protein intake group.\n\nResultsWe confirmed that epinephrine (Epi) microinjected into the lateral ventricle (LV) of conscious NP rats leads to enhanced natriuresis followed by a reduction in arterial pressure. This response was associated with increased proximal and post-proximal sodium excretion accompanied by an unchanged glomerular filtration rate. The current study showed in both, NP and LP offspring that natriuretic effect of Epi injection into the LV was abolished by prior local microinjection of an 1-adrenoceptor antagonist (prazosin). Conversely, LV 2-adrenoceptor antagonist (yohimbine) administration potentiated the action of epinephrine. The LV yohimbine pretreatment normalized urinary sodium excretion and reduced the blood pressure in LP compared with age-matched NP offspring.\n\nConclusionThese are, as far as we are aware, the first results showing the role of central adrenergic receptors interaction on hypertension pathogenesis in maternal protein-restricted fetal programming offspring. The study also provides good evidence of the existence of central nervous system adrenergic mechanisms consisting of 1 and 2-adrenoceptors, which works reciprocally on the control of renal sodium excretion and blood pressure. Although the precise mechanism of the different natriuretic response of NP and LP rats is still uncertain, these results led us to speculate that inappropriate neural adrenergic pathways might have significant effects on tubule sodium transport, resulting in the inability of the kidneys to control hydrosaline balance, and, consequently, an increase in blood pressure.

physiology↗

bioRxiv2017

Gestational low-protein intake enhances the whole kidney miR-192 and miR-200 family expression and epithelial-to-mesenchymal transition in adult male offspring

BackgroundStudies have been showed that maternal protein-restricted adult offspring, present pronounced reduction of nephron number associated with decreased fractional urinary sodium excretion and arterial hypertension. Also, recent advances in our understanding of the molecular pathways that govern the association of gestational nutritional restriction, intrauterine growth retardation inflammation with impaired nephrogenesis, nephron underdosing and kidney fibrosis point to the epithelial to mesenchymal transition (EMT) as the common.\n\nMethodIn the current study, the protein and sodium urinary excretion rates were evaluated and immunohistochemistry and western blot techniques were used to characterize the whole kidney structure changes in 16-wk old male LP offspring compared with age-matched controls. We also verify the expression of miRNAs, mRNAs and proteins markers of fibrosis and epithelial-to-mesenchymal transition in entire kidney prepared from LP offspring.\n\nResultsIn the current study, we may assume that arterial hypertension and long-term hyperfiltration process manifests, itself by proteinuria was accompanied by increased whole kidney mRNA expression of TGF-{beta}1, ZEB1, type I collagen and, fibronectin in parallel to decreased expression of E-cadherin in 16-wk old LP offspring. Surprisingly, the renal tissue miR-129, miR-141, miR-200c and miR-429 were significantly upregulated in LP offspring compared to age-matched NP rats.\n\nConclusionConsidering that the overload in remaining nephrons, we may state that hypertension and proteinuria development following maternal protein restriction, may be a preponderant factor for the development of EMT and fibrous process and altered kidney ultrastructure in rat offspring. However, further studies are required to assess the contribution of miRNAs on renal injury progression in gestational protein-restricted model of fetal programming.

developmental biology↗