Enhancing skeletal muscle growth is crucial for animal agriculture because skeletal muscle provides meat for human consumption. An increasing body of evidence shows that the level of maternal nu- trition alters fetal skeletal muscle development, with long-term effects on offspring growth and performance. Fetal skeletal muscle development mainly involves myo- genesis (i.e., muscle cell development), but also involves adipogenesis (i.e., adipocyte development) and fibro- genesis (i.e., fibroblast development). These tissues in fetal muscle are mainly derived from mesenchymal stem cells (MSC). Shifting the commitment of MSC from myogenesis to adipogenesis increases intramuscular fat (i.e., marbling), improving the quality grade of meats. Strong experimental evidence indicates that Wingless and Int (Wnt)/β-catenin signaling regulates MSC dif- ferentiation. Upregulation of Wnt/β-catenin promotes myogenesis, and downregulation enhances adipogene- sis. A lack of nutrients in early to midgestation reduces the formation of secondary muscle fibers in ruminant animals. Nutrient deficiency during mid- to late gesta- tion decreases the number of intramuscular adipocytes and muscle fiber sizes. Knowledge of this regulatory mechanism will allow the development of strategies to enhance muscle growth and marbling in offspring, espe- cially in the setting of nutrient deficiency.

/pdf/fetal-programming-of-skeletal-muscle-development-in-ruminant-130i5eygd3.pdf

Fetal programming of skeletal muscle development in ruminant animals.

Appropriate in utero growth is essential for offspring development and is a critical contributor to long-term health. Fetal growth is largely dictated by the availability of nutrients in maternal circulation and the ability of these nutrients to be transported into fetal circulation via the placenta. Substrate flux across placental gradients is dependent on the accessibility and activity of nutrient-specific transporters. Changes in the expression and activity of these transporters is implicated in cases of restricted and excessive fetal growth, and may represent a control mechanism by which fetal growth rate attempts to match availability of nutrients in maternal circulation. This review provides an overview of placenta nutrient transport with an emphasis on macro-nutrient transporters. It highlights the changes in expression and activity of these transporters associated with common pregnancy pathologies, including intrauterine growth restriction, macrosomia, diabetes and obesity, as well as the potential impact of maternal diet. Molecular signaling pathways linking maternal nutrient availability and placenta nutrient transport are discussed. How sexual dimorphism affects fetal growth strategies and the placenta’s response to an altered intrauterine environment is considered. Further knowledge in this area may be the first step in the development of targeted interventions to help optimize fetal growth.

https://www.mdpi.com/1422-0067/15/9/16153/pdf

Maternal-fetal nutrient transport in pregnancy pathologies: the role of the placenta.

Maternal nutrient restriction (NR) affects fetal development with long-term consequences on postnatal health of offspring, including predisposition to obesity and diabetes Most studies have been conducted in fetuses in late gestation, and little information is available on the persistent impact of NR from early to mid-gestation on properties of offspring skeletal muscle, which was the aim of this study Pregnant ewes were subjected to 50% NR from day 28–78 of gestation and allowed to deliver The longissimus dorsi muscle was sampled from 8-month-old offspring Maternal NR during early to mid-gestation decreased the number of myofibres in the offspring and increased the ratio of myosin IIb to other isoforms by 176 ± 49% (P < 005) compared with offspring of ad libitum fed ewes Activity of carnitine palmitoyltransferase-1, a key enzyme controlling fatty acid oxidation, was reduced by 247 ± 45% (P < 005) in skeletal muscle of offspring of NR ewes and would contribute to increased fat accumulation observed in offspring of NR ewes Intramuscular triglyceride content (IMTG) was increased in skeletal muscle of NR lambs, a finding which may be linked to predisposition to diabetes in offspring of NR mothers, since enhanced IMTG predisposes to insulin resistance in skeletal muscle Proteomic analysis by two-dimensional gel electrophoresis demonstrated downregulation of several catabolic enzymes in 8-month-old offspring of NR ewes These data demonstrate that the early to mid-gestation period is important for skeletal muscle development Impaired muscle development during this stage of gestation affects the number and composition of fibres in offspring which may lead to long-term physiological consequences, including predisposition to obesity and diabetes

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphysiol.2006.112110

Maternal nutrient restriction affects properties of skeletal muscle in offspring

Developmental programming is the concept that a maternal stimulus or insult at a critical period in fetal development has long-term effects on the offspring. Historically, considerable effort has been made to understand how nutrition influences health and productivity during the postnatal period. Whereas maternal nutrition during pregnancy plays an essential role in proper fetal and placental development, less is known about how maternal nutrition affects the health and productivity of the offspring. Conceptus growth is sensitive to direct and indirect effects of maternal dietary intake. Even from the earliest stages of embryonic life, when nutrient requirements for conceptus growth are negligible, alterations in tissue composition can occur, influencing future growth of the compromised organ system. Not only is neonatal health compromised, but subsequent health may also be programmed because offspring from undernourished dams have exhibited poor growth and productivity and have developed significant diseases later in life. Although the literature is now evolving, with increasing evidence of how maternal nutrient restriction impairs several prenatal physiological variables, few studies have evaluated postnatal growth and development in livestock species, and fewer have evaluated it in beef cattle. In addition, very few studies have evaluated restriction of specific components of the diet during pregnancy (such as protein) on offspring growth and performance. This review focuses on how maternal nutrition affects conceptus growth and postnatal responses in beef cattle.

/pdf/effects-of-maternal-nutrition-on-conceptus-growth-and-4moabp7nw0.pdf

Effects of maternal nutrition on conceptus growth and offspring performance: implications for beef cattle production.

In this study we determined body weight-specific fetal (umbilical) glucose uptake (UGU), utilization (GUR), and production rates (GPR) and insulin action in intrauterine growth-restricted (IUGR) fe...

https://www.physiology.org/doi/pdf/10.1152/ajpendo.00459.2007

Increased insulin sensitivity and maintenance of glucose utilization rates in fetal sheep with placental insufficiency and intrauterine growth restriction

This study utilized maternal undernutrition from early to midgestation in the ewe to determine the impact(s) of intrauterine growth restriction on postpartum growth of male offspring and the potential mechanisms involved. Multiparous ewes were fed 50% (nutrient-restricted) or 100% (control-fed) of their nutrient requirements (NRC, 1985) between d 28 and 78 of gestation, and then all ewes were fed 100% of the NRC requirements from d 79 through lambing. Male lambs born to nutrient-restricted (n = 9) and control-fed (n = 9) ewes exhibited similar BW (5.8 vs. 6.0 +/- 0.3 kg) and crown-rump lengths (53.8 vs. 55.4 +/- 1.0 cm) at birth. At 63 and 250 d of postnatal age, wether lambs were subjected to a glucose tolerance test, in which a bolus of glucose was administered i.v. to evaluate changes in glucose and insulin concentrations. After i.v. glucose administration at 63 d of age, lambs from nutrient-restricted ewes exhibited a greater area under the curve for glucose (AUCg; 6,281 vs. 5,242 +/- 429; P < 0.05) and insulin (AUCi; 21.0 vs. 8.6 +/- 1.9; P < 0.001) than lambs from control-fed ewes. After glucose administration at 250 d of age, lambs from nutrient-restricted ewes had greater AUCg (7,147 vs. 5,823 +/- 361; P < 0.01) but a lower AUCi (6.4 vs. 10.2 +/- 1.9; P = 0.05) than lambs from control-fed ewes. Lambs from nutrient-restricted ewes were heavier (26.6 vs. 21.8 +/- 2.3 kg; P < 0.05) and had more backfat (0.30 vs. 0.21 +/- 0.03 cm, P < 0.05) by 4 mo of age than the lambs from control-fed ewes. At slaughter at 280 d of age, lambs from nutrient-restricted ewes remained heavier than lambs from control-fed ewes, had greater (P < 0.05) amounts of kidney and pelvic-area adipose tissue, and tended (P < 0.10) to have reduced LM and semitendinosus muscle weights as a percentage of HCW. These data demonstrate that a bout of maternal undernutrition during early to midgestation in sheep increased BW and fat deposition during adolescence and dysregulated glucose uptake in the absence of any change in birth weight.

Maternal undernutrition during early to mid-gestation in the ewe results in altered growth, adiposity, and glucose tolerance in male offspring.

To evaluate the impacts of the COVID-19 pandemic on anxiety and depression symptoms in pregnant women and their relationship with pregnancy outcomes, 1087 pregnant women completed online questionnaires. Anxiety symptoms were measured using the Self-Rating Anxiety Scale (SAS). Depression was assessed using the Edinburgh Postnatal Depression Scale (EPDS), and the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Univariate analysis and logistic regression analysis were used to determine the association between depression and anxiety symptoms, participants’ characteristics, and pregnancy outcomes. Of the 986 pregnant women who were included in this study, the rates of anxiety symptoms and depressive tendencies were 13.4% and 18.3%, respectively. Sleep disorder ((Adjusted odds ratio, AOR = 4.166; 95% confidence interval, CI: 2.797–6.205), time spent paying attention to the epidemic per day (≥1 h/d AOR = 1.568; 95% CI: 1.052–2.338), and the time spent with their spouses (Increase AOR = 0.629; 95% CI: 0.409–0.967) were associated with the risk of anxiety. Sleep disorder (AOR = 3.839; 95% CI: 2.718–5.432) and educational level (bachelor’s degree or above AOR = 1.833; 95% CI: 1.004–3.345) were associated with the risk of depression. Psychological status was not correlated with the pregnancy outcomes (p > 0.05). Anxiety and depression symptoms were common among pregnant women during the COVID-19 pandemic. Special attention should be paid to manage their risk factors.

/pdf/impacts-of-the-covid-19-pandemic-on-anxiety-and-depressive-3f2u1hyb.pdf

H. Han

Papers

Maternal undernutrition during early to mid-gestation in the ewe results in altered growth, adiposity, and glucose tolerance in male offspring.

Impacts of the COVID-19 Pandemic on Anxiety and Depressive Symptoms in Pregnant Women and Related Perinatal Outcomes