Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat

Obese mice have decreased uterine contractility and altered energy metabolism in the uterus at term gestation†

Over 35% of reproductive-age women in the USA have obesity, putting them at increased risk for numerous obstetric complications due to abnormal labor. While the association between maternal obesity and abnormal labor has been well documented, the mechanisms responsible for this remain understudied. The uterine smooth muscle, myometrium, has high energy needs in order to fuel regular uterine contractions during parturition. However, the precise mechanisms by which the myometrium meets its energy demands has not been defined. Here, our objective was to define the effects of obesity on energy utilization in the myometrium during labor. We generated a mouse model of maternal diet-induced obesity and found that these mice had a higher rate of dystocia than control chow-fed mice. Moreover, compared to control chow-fed mice, DIO mice at term, both before and during labor had lower in vivo spontaneous uterine contractility. Untargeted transcriptomic and metabolomic analyses suggest that diet-induced obesity is associated with elevated long-chain fatty acid uptake and utilization in the uterus, but also an accumulation of medium-chain fatty acids. Diet-induced obesity uteri also had an increase in the abundance of long chain-specific beta-oxidation enzymes, which may be responsible for the observed increase in long-chain fatty acid utilization. This altered energy substrate utilization may be a contributor to the observed contractile dysfunction.

The impact of maternal obesity on in vivo uterine contractile activity during parturition in the rat

Maternal obesity is associated with increased risk of prolonged and dysfunctional labor and emergency caesarean section. To elucidate the mechanisms behind the associated uterine dystocia, a translational animal model is required. Our previous work identified that exposure to a high-fat, high-cholesterol (HFHC) diet to induce obesity down-regulates uterine contractile associated protein expression and causes asynchronous contractions ex vivo. This study aims to investigate the impact of maternal obesity on uterine contractile function in vivo using intrauterine telemetry surgery. Virgin female Wistar rats were fed either a control (CON, n = 6) or HFHC (n = 6) diet for 6 weeks prior to conception, and throughout pregnancy. On Day 9 of gestation, a pressure-sensitive catheter was surgically implanted aseptically within the gravid uterus. Following 5 days recovery, intrauterine pressure (IUP) was recorded continuously until delivery of the 5th pup (Day 22). HFHC induced obesity led to a significant 1.5-fold increase in IUP (p = 0.026) and fivefold increase in frequency of contractions (p = 0.013) relative to CON. Determination of the time of labor onset identified that HFHC rats IUP (p = 0.046) increased significantly 8 h prior to 5th pup delivery, which contrasts to CON with no significant increase. Myometrial contractile frequency in HFHC rats significantly increased 12 h prior to delivery of the 5th pup (p = 0.023) compared to only 3 h in CON, providing evidence that labor in HFHC rats was prolonged by 9 h. In conclusion, we have established a translational rat model that will allow us to unravel the mechanism behind uterine dystocia associated with maternal obesity.

High Fat High Sucrose Diet Modifies Uterine Contractility and Cervical Resistance in Pregnant Rats: The Roles of Sex Hormones, Adipokines and Cytokines

Background: In obesity, the adipose tissue becomes a very significant endocrine organ producing different factors called adipokines, such as leptin, adiponectin and kisspeptin; however, no data are available about their actions on uterine contraction in obese pregnant rats. Our aim was to study the impact of obesity on pregnant uterine contraction in a rat model. Methods: Obesity was induced by the consumption of a high fat high sucrose diet (HFHSD) for 9 weeks, including pregnancy. Glucose tolerance, sex hormone, cytokine and adipokine levels were measured. Uterine contractions and cervical resistance, as well as their responses to adipokines, were tested along with the expressions of their uterine receptors. Results: HFHSD increased body weight, and altered glucose tolerance and fat composition. The uterine leptin and kisspeptin pathway affect increased. The levels of proinflammatory cytokines were reduced, while the plasma level of progesterone was increased, resulting in weaker uterine contractions, and improving the uterine relaxing effects of adipokines. HFHSD reduced cervical resistance, but the core effect of adipokines is difficult to determine. Conclusions: Obesity in pregnant rats reduces uterine contractility and cytokine-induced inflammatory processes, and therefore obese pregnant rat methods are partially applicable for modelling human processes.

The Impact of Obesity on the Management and Outcomes of Postpartum Hemorrhage

OBJECTIVE

The study aimed to evaluate the impact of obesity on the management and outcomes of postpartum hemorrhage.

STUDY DESIGN

We conducted a retrospective cohort study of women who delivered at a tertiary care center between February 1, 2013 and January 31, 2014 and experienced a postpartum hemorrhage. Charts were reviewed for clinical and sociodemographic data, and women were excluded if the medical record was incomplete. Hemorrhage-related severe morbidity indicators included blood transfusion, shock, renal failure, transfusion-related lung injury, cardiac arrest, and use of interventional radiology procedures. Obese (body mass index [BMI] ≥ 30 kg/m²) and nonobese women were compared. Data were analyzed using Chi-square, Student's t-test, Mann-Whitney U test, and linear regression where appropriate. The p-value <0.05 was significant.

RESULTS

Of 9,890 deliveries, 2.6% (n = 262) were complicated by hemorrhage. Obese women were more likely to deliver by cesarean section (55.5 vs. 39.8%, p = 0.016), undergo a cesarean after labor (31.1 vs. 12.2%, p = 0.001), and have a higher quantitative blood loss (1,313 vs. 1,056 mL, p = 0.003). Both groups were equally likely to receive carboprost, methylergonovine, and misoprostol, but obese women were more likely to receive any uterotonic agent (95.7 vs. 88.9%, p = 0.007) and be moved to the operating room (32.3 vs. 20.4, p = 0.04). There was no difference in the use of intrauterine pressure balloon tamponade, interventional radiology, or decision to proceed with hysterectomy. The two groups were similar in time to stabilization. There was no difference in the need for blood transfusion. Obese women required more units of blood transfused (2.2 ± 2 vs. 2 ± 5 units, p = 0.023), were more likely to have any hemorrhage-related severe morbidity (34.1 vs. 25%, p = 0.016), and more than one hemorrhage related morbidity (17.1 vs. 7.9, p = 0.02). After controlling for confounding variables, quantitative blood loss, and not BMI was predictive of the need for transfusion.

CONCLUSION

Despite similar management, obese women were more likely to have severe morbidity and need more units of blood transfused.

KEY POINTS

· Obese women were more likely to have a higher quantitative blood loss and require more units of blood transfused.. · Obese women were more likely to experience any hemorrhage-related severe morbidity.. · Although obese women were more likely to be moved to the operating room for intervention, the rates of intrauterine pressure balloon tamponade, interventional radiology or hysterectomy were the same for obese and non-obese women..

Spirulina platensis Consumption Prevents Obesity and Improves the Deleterious Effects on Intestinal Reactivity in Rats Fed a Hypercaloric Diet

The consumption of hypercaloric diets is related to the development of obesity, favoring the etiology of gastrointestinal disorders. In this context, Spirulina platensis (SP), some blue-green algae with antioxidant action, appears as a potential therapeutic alternative to prevent obesity and associated intestinal disorders. Thus, the present study is aimed at evaluating the deleterious effects of the hypercaloric diet on the contractile and relaxing reactivity of the ileum of rats, as well as the possible preventive mechanisms of dietary supplementation with SP. Wistar rats were divided into three groups: fed a standard diet (SD), a hypercaloric diet (HCD), and/or supplemented with 25 mg/kg SP (HCD + SP25) for 8 weeks. The hypercaloric diet was effective in promoting obesity in rats, as well as decreasing potency and ileal relaxing and contractile efficacy. In contrast, dietary supplementation with SP was able to prevent some of the parameters of experimental obesity. In addition, SP prevented the reduction of intestinal reactivity, possibly due to a positive modulation of voltage-gated calcium channels (CaV) and negative regulation of muscarinic receptors (M3). Thus, food supplementation with Spirulina platensis becomes a promising alternative in the prevention of gastrointestinal diseases induced and/or aggravated by obesity.

The Myometrium in Pregnant Women with Obesity

Obesity is a worldwide public health problem, affecting at least one-third of pregnant women. One of the main problems of obesity during pregnancy is the resulting high rate of cesarean section. The leading cause of this higher frequency of cesarean sections in obese women, compared with that in nonobese women, is an altered myometrial function that leads to lower frequency and potency of contractions. In this article, the disruptions of myometrial myocytes were reviewed in obese women during pregnancy that may explain the dysfunctional labor. The myometrium of obese women exhibited lower expression of connexin43, a lower function of the oxytocin receptor, and higher activity of the potassium channels. Adipokines, such as leptin, visfatin, and apelin, whose concentrations are higher in obese women, decreased myometrial contractility, perhaps by inhibiting the myometrial RhoA/ROCK pathway. The characteristically higher cholesterol levels of obese women alter myometrial myocyte cell membranes, especially the caveolae, inhibiting oxytocin receptor function, and increasing the K+ channel activity. All these changes in the myometrial cells or their environment decrease myometrial contractility, at least partially explaining the higher rate of cesarean of sections in obese women.

Obesity, Second Stage Duration, and Labor Outcomes in Nulliparous Women

OBJECTIVE

This study aimed to estimate second stage duration and its effects on labor outcomes in obese versus nonobese nulliparous women.

STUDY DESIGN

This was a secondary analysis of a cohort of nulliparous women who presented for labor at term and reached complete cervical dilation. Adjusted relative risks (aRR) were used to estimate the association between obesity and second stage characteristics, composite neonatal morbidity, and composite maternal morbidity. Effect modification of prolonged second stage on the association between obesity and morbidity was assessed by including an interaction term in the regression model.

RESULTS

Compared with nonobese, obese women were more likely to have a prolonged second stage (aRR: 1.48, 95% CI: 1.18-1.85 for ≥3 hours; aRR: 1.65, 95% CI: 1.18-2.30 for ≥4 hours). Obesity was associated with a higher rate of second stage cesarean (aRR: 1.78, 95% CI: 1.34-2.34) and cesarean delivery for fetal distress (aRR: 2.67, 95% CI: 1.18-3.58). Obesity was also associated with increased rates of neonatal (aRR: 1.38, 95% CI: 1.05-1.80), but not maternal morbidity (aRR: 1.06, 95% CI: 0.90-1.25). Neonatal morbidity risk was not modified by prolonged second stage.

CONCLUSION

Obesity is associated with increased risk of neonatal morbidity, which is not modified by prolonged second stage of labor.

Metabolic Pathways Associated With Term Labor Induction Course in African American Women

OBJECTIVES

The purpose of this study was to evaluate differences in the metabolic pathways activated in late-pregnancy serum samples among African American women who went on to have term (≥37 weeks) labor induction requiring high total oxytocin doses to complete first-stage labor compared to those in similar women with low-oxytocin labor inductions.

STUDY DESIGN

Case-control study (N = 27 women with labor induction with successful cervical ripening: 13 requiring the highest total doses of synthetic oxytocin to progress from 4- to 10-cm cervical dilation and 14 requiring the lowest total doses) with groups balanced on parity and gestational age. Serum samples obtained between 24 and 30 weeks' gestation were analyzed using ultra-high-resolution metabolomics. Differentially expressed metabolites between high-oxytocin induction cases and low-oxytocin induction comparison subjects were evaluated using linear regression with xmsPANDA. Metabolic pathways analysis was conducted using Mummichog Version 2.0, with discriminating metabolites annotated using xMSannotator Version 1.3.

RESULTS

Labor processes were similar by group with the exception that cases received over 6 times more oxytocin between 4- and 10-cm cervical dilation than comparison women. Induction requiring high total doses of synthetic oxytocin was associated with late-pregnancy serum levels of metabolites from the linoleate and fatty acid activation pathways in term, African American women.

CONCLUSION

Serum levels of several lipid metabolites predicted more complicated labor induction involving higher doses of synthetic oxytocin to complete first-stage labor. Further investigation in larger, more diverse cohorts of women is needed to identify potential targets to prevent failed labor induction.

Metabolomic Pathways Predicting Labor Dystocia by Maternal Body Mass Index

Objectives  The purpose of this study was to evaluate the metabolic pathways activated in the serum of African-American women during late pregnancy that predicted term labor dystocia. Study Design  Matched case-control study ( n  = 97; 48 cases of term labor dystocia and 49 normal labor progression controls) with selection based on body mass index (BMI) at hospital admission and maternal age. Late pregnancy serum samples were analyzed using ultra-high-resolution metabolomics. Differentially expressed metabolic features and pathways between cases experiencing term labor dystocia and normal labor controls were evaluated in the total sample, among women who were obese at the time of labor (BMI ≥ 30 kg/m2), and among women who were not obese. Results  Labor dystocia was predicted by different metabolic pathways in late pregnancy serum among obese (androgen/estrogen biosynthesis) versus nonobese African-American women (fatty acid activation, steroid hormone biosynthesis, bile acid biosynthesis, glycosphingolipid metabolism). After adjusting for maternal BMI and age in the total sample, labor dystocia was predicted by tryptophan metabolic pathways in addition to C21 steroid hormone, glycosphingolipid, and androgen/estrogen metabolism. Conclusion  Metabolic pathways consistent with lipotoxicity, steroid hormone production, and tryptophan metabolism in late pregnancy serum were significantly associated with term labor dystocia in African-American women.

Preventing Cesarean Birth in Women with Obesity: Influence of Unit-Level Midwifery Presence on Use of Cesarean among Women in the Consortium on Safe Labor Data Set

INTRODUCTION

Maternal obesity is associated with slow labor progression and unplanned cesarean birth. Midwives use fewer medical interventions during labor, and the women they care for have lower cesarean birth rates, compared with low-risk, matched groups of women cared for by physicians. The primary aim of this study was to examine associations between midwifery unit-level presence and unplanned cesarean birth in women with different body mass index (BMI) ranges. Unit-level presence of midwives was analyzed as a representation of a unique set of care practices that exist in settings where midwives work.

METHODS

A retrospective cohort study was conducted using Consortium on Safe Labor data from low-risk, healthy women who labored and gave birth in medical centers with (n = 9795) or without (n = 13,398) the unit-level presence of midwives. Regression models were used to evaluate for associations between unit-level midwifery presence and 1) the incidence of unplanned cesarean birth and 2) in-hospital labor durations with stratification by maternal BMI and adjustment for maternal demographic and pregnancy factors.

RESULTS

The odds of unplanned cesarean birth among women who gave birth in centers with midwives were 16% lower than the odds of cesarean birth among similar women at who gave birth at centers without midwives (adjusted odds ratio, 0.84; 95% CI, 0.77-0.93). However, women whose BMI was above 35.00 kg/m2 at labor admission had similar odds of cesarean birth, regardless of unit-level midwifery presence. In-hospital labor duration prior to unplanned cesarean was no different by unit-level midwifery presence in nulliparous women whose BMI was above 35.00 kg/m2 .

DISCUSSION

Although integration of midwives into the caregiving environment of medical centers in the United States was associated with overall decrease in the incidence of cesarean birth, increased maternal BMI nevertheless remained positively associated with these outcomes.

Inhibition of gap junction composed of Cx43 prevents against acute kidney injury following liver transplantation

Postoperative acute kidney injury (AKI) is a severe complication after liver transplantation (LT). Its deterioration and magnification lead to the increase in mortality. Connexin43 (Cx43) mediates direct transmission of intracellular signals between neighboring cells, always considered to be the potent biological basis of organ damage deterioration and magnification. Thus, we explored the effects of Cx43 on AKI following LT and its related possible mechanism. In this study, alternations of Cx43 expression were observed in 82 patients, receiving the first-time orthotopic LT. We built autologous orthotopic liver transplantation (AOLT) models with Sprague–Dawley (SD) rats in vivo, and hypoxia-reoxygenation (H/R) or lipopolysaccharide (LPS) pretreatment models with kidney tubular epithelial cells (NRK-52E) in vitro, both of which were the most important independent risk factors of AKI following LT. Then, different methods were used to alter the function of Cx43 channels to determine its protective effects on AKI. The results indicated that patients with AKI suffering from longer time of tracheal intubation or intensive care unit stay, importantly, had significantly lower survival rate at postoperative 30 days and 3 years. In rat AOLT models, as Cx43 was inhibited with heptanol, postoperative AKI was attenuated significantly. In vitro experiments, downregulation of Cx43 with selective inhibitors, or siRNA protected against post-hypoxic NRK-52E cell injuries caused by H/R and/or LPS, while upregulation of Cx43 exacerbated the above-mentioned cell injuries. Of note, alternation of Cx43 function regulated the content of reactive oxygen species (ROS), which not only mediated oxidative stress and inflammation reactions effectively, but also regulated necroptosis. Therefore, we concluded that Cx43 inhibition protected against AKI following LT through attenuating ROS transmission between the neighboring cells. ROS alternation depressed oxidative stress and inflammation reaction, which ultimately reduced necroptosis. This might offer new insights for targeted intervention for organ protection in LT, or even in other major surgeries.

Dietary supplementation of barley and/or dates attenuate hypercholesterolemic-induced endometrial dysfunction in Wistar albino rats via alleviation of apoptotic pathways and enhancing oxidative capacity

Our study was conducted to characterize the efficacy of barley and/or date palm fruits (10%) in alleviation of hypercholesterolemic endometrial insults in obese rat model. Sixty-four Wistar albino rats were randomized into eight groups (n = 8); control, hypercholesterolemic- and hypercholesterolemic-treated groups. Animals were subjected to treatment for 4 months. After sacrifice, serum and uterine tissues were collected and processed for biochemical, histological, immunohistochemical, and electron microscopic investigations. In hypercholesterolemic rats, the endometrium displayed hyperplasia with necrotic patches in the surface epithelium and its glandular lining cells. Also, there was a remarkable increase in the endometrial thickness and significant decrease in corresponding glandular numbers. Prompted by these findings, immunohistochemical localization revealed that expression of proliferating cell nuclear antigen was downregulated, while cleaved caspase-3 was upregulated in the endometrial cells in hypercholesterolemic group. Accordingly, there was remarkable depletion of antioxidant enzymatic activities associated with increased lipid peroxidation and apoptotic markers. Contradictory, supplementation of barley and/or dates to hypercholesterolemic groups showed intriguing amelioration for the histological architecture of the endometrium and balancing its oxidative redox. In conclusion, the administration of barley and/or dates confers enhanced synergistic effects in attenuation of hypercholesterolemic induced-endometrial dysfunction. This is clear evidence that endometrial amelioration was directly linked to the implication of highly potential antioxidant capacity of barley and/or dates phytochemicals, β-glucan, polyphenols, and other trace elements, which can be utilized to establish a phyto-therapeutic strategy for activating endometrial cell regeneration. PRACTICAL APPLICATIONS: Barley and dates confer both hypoglycemic and hypocholesterolemic potentials. Therefore, their ingredients would be implicated in the amelioration of uterine functions in obese women. These favorable potentials were directly linked to the restraining of endometrial inflammation and retrieving the oxidative capacity. Furthermore, our findings demonstrated that barley and dates substantially diminished the expression of TNF-α, mitigated DNA damage and prevented leukocytic infiltration in the endometrial tissue; based on their high content of dietary phytochemicals, β-glucan, polyphenols, and other trace elements.

Influence of Body Mass Index on Gestation and Delivery in Nulliparous Women: A Cohort Study

Aims: To assess the influence of obesity on pregnancy and delivery in pregnant nulliparous women. Methods: A cohort, longitudinal, retrospective study was conducted in Spain with 710 women, of which 109 were obese (BMI > 30) and 601 were normoweight (BMI < 25). Consecutive nonrandom sampling. Variables: maternal age, BMI, gestational age, fetal position, start of labor, dilation and expulsion times, type of delivery and newborn weight and height. Results: The dilation time in obese women (309.81 ± 150.42 min) was longer than that in normoweight women (281.18 ± 136.90 min) (p = 0.05, Student's t-test). A higher fetal weight was more likely to lead to longer dilation time (OR = 0.43, 95% CI 0.010-0.075, p < 0.001) and expulsion time (OR = 0.027, 95% CI 0.015-0.039, p < 0.001). A higher maternal age was more likely to lead to a longer expulsion time (OR = 2.054, 95% CI 1.17-2.99, p < 0.001). Obese women were more likely to have gestational diabetes [relative risk (RR) = 3.612, 95% CI 2.102-6.207, p < 0.001], preeclampsia (RR = 5.514, 95% CI 1.128-26.96, p = 0.05), induced birth (RR = 1.26, 95% CI 1.06-1.50, p = 0.017) and cesarean section (RR = 2.16, 95% CI 1.11-4.20, p = 0.022) than normoweight women. Conclusion: Obesity is associated with increased complications during pregnancy, an increased incidence of a cesarean section and induced birth but it has no significant effect on the delivery time.

Anti-hypercholesterolemic impacts of barley and date palm fruits on the ovary of Wistar albino rats and their offspring

A high cholesterol diet is related to ovarian dysfunction and infertility which has been increased among young ages consuming processed food products. The present study was conducted to evaluate the role of a high cholesterol diet on the ovaries of young female rats via assessments of histopathology, immunohistochemistry, oxidative stress and apoptic markers. Also, mating of hypercholesterolemic female rats was carried out to measure the fertility and numbers of their offspring. At the same time, phytotherapy was carried out through supplementing the diet with barley and/ or date palm fruits (10%) during the experiment to assess the phyto-therapeutic impacts in attenuation of drastic hypercholesterolemic effects. Hypercholesterolemic diet-fed rats exhibited damage of the ovarian follicles and increased follicular atresia. Furthermore, expression of cleaved caspase-3 was upregulated, while PCNA was downregulated in granulosa, theca and stroma cells. Hypercholesterolemic female rats showed marked depletion of antioxidative enzymes, increased lipid peroxidation and apoptotic markers. Alterations to the female serum hormones were detected. Offspring maternally fed on hypercholesterolemic diet showed a significant decrease of body weight and altered sex ratio. However, concomitant supplementation of barley and or date fruits to hypercholesterolemic groups revealed marked improvement of ovarian structure and function. On the basis of these evidences, it is believed that the enhanced synergistic effects of barley and/or date palm fruits in the amelioration of ovarian structure and functions were elicited by the potential antioxidant activity of their phytomicronutrients, polyphenols, β-glucan and trace elements. These materials scavenge free radicals from inflamed cells that can be used to establish an effective and novel therapeutic strategy for activating ovarian cell regeneration.

Maternal obesity-induced decreases in plasma, hepatic and uterine polyunsaturated fatty acids during labour is reversed through improved nutrition at conception

Maternal obesity is associated with prolonged and dysfunctional labour, potentially through decreased synthesis of prostaglandins that stimulate myometrial contractions. We assessed the impact of maternal obesity on concentrations of precursor fatty acids (FA) for prostaglandin synthesis and whether any changes could be reversed by improved nutrition post-conception. Wistar rats were fed control (CON) or High-Fat, High-cholesterol (HFHC) diets 6 weeks before mating. At conception half the dams switched diets providing 4 dietary groups: (1) CON, (2) HFHC, (3) CON-HFHC or (4) HFHC-CON. During parturition rats were euthanized and FA composition of plasma, liver and uterus determined. Visceral fat was doubled in rats exposed to the HFHC diet prior to and/or during pregnancy compared to CON. HFHC diet increased MUFAs but decreased omega-3 and omega-6 PUFAs in plasma and liver. Uterine omega-3 FA concentrations were halved in HFHC versus CON rats, but all other FAs were similar. Switching from HFHC to CON diet at conception restored all FA profiles to those seen in CON rats. The increased MUFA and decreased PUFA concentrations in obese HFHC dams may contribute to aberrant prostaglandin synthesis and dysfunctional myometrial activity and it may be possible to reverse these changes, and potentially improve labour outcomes, by improving nutrition at conception.

Obesity in pregnancy: a novel concept on the roles of adipokines in uterine contractility

Obesity is a global health problem even among pregnant women. Obesity alters quality of labor, such as preterm labor, prolonged labor, and higher oxytocin requirements in pregnant women. The most important factors to play a role in the altered gestational period and serve as drug targets to treat the consequences are female sexual hormones, calcium channels, adrenergic system, oxytocin, and prostaglandins. However, we have limited information about the impact of obesity on the pregnant uterine contractility and gestation time. Adipose tissue, which is the largest endocrine and paracrine organ, especially in obesity, is responsible for the production of adipokines and various cytokines and chemokines, and there are no reliable data available describing the relation between body mass index, glucose intolerance, and adipokines during pregnancy. Recent data suggest that the dysregulation of leptin, adiponectin, and kisspeptin during pregnancy contributes to gestational diabetes mellitus and pre-eclampsia. A preclinical method for obese pregnancy should be developed to clarify the action of adipokines and assess their impact in obesity. The deeper understanding of the adipokines-induced processes in obese pregnancy may be a step closer to the prevention and therapy of preterm delivery or prolonged pregnancy. Gestational weight gain is one of the factors that could influence the prenatal development, birth weight, and adiposity of newborn.

Hypercholesterolemia impairs oxytocin-induced uterine contractility in late pregnant mouse

High cholesterol is known to negatively affect uterine contractility inex vivoconditions. The aim of the present study was to reveal the effect ofin vivohypercholesterolemia on spontaneous and oxytocin-induced uterine contractility in late pregnant mouse uterus. Female Swiss albino mice were fed with high cholesterol (HC) diet (0.5% sodium cholate, 1.25% cholesterol and 15% fat) for 6 weeks and then throughout the gestation period after mating. On day 19 of gestation, serum cholesterol level was increased more than 3-fold while triglycerides level was reduced in HC diet-fed animals as compared to control animals fed with a standard diet. In tension experiments, neither the mean integral tension of spontaneous contractility nor the response to CaCl2in high K+-depolarized tissues was altered, but the oxytocin-induced concentration-dependent contractile response in uterine strips was attenuated in hypercholesterolemic mice as compared to control. Similarly, hypercholesterolemia dampened concentration-dependent uterine contractions elicited by a GNAQ protein activator,Pasteurella multocidatoxin. However, it had no effect on endogenous oxytocin level either in plasma or in uterine tissue. It also did not affect the prostaglandin release in oxytocin-stimulated tissues. Western blot data showed a significant increase in caveolin-1 and GRK6 proteins but decline in oxytocin receptor, GNAQ and RHOA protein expressions in hypercholesterolemic mouse uterus. The results of the present study suggest that hypercholesterolemia may attenuate the uterotonic action of oxytocin in late pregnancy by causing downregulation of oxytocin receptors and suppressing the signaling efficacy through GNAQ and RHOA proteins.

GDM-Induced Macrosomia Is Reversed by Cav-1 via AMPK-Mediated Fatty Acid Transport and GLUT1-Mediated Glucose Transport in Placenta

Objective

To investigate if the role of Cav-1 in GDM-induced macrosomia is through regulating AMPK signaling pathway in placenta.

Methods

We used diagnostic criteria of gestational diabetes mellitus (GDM) and macrosomia to separate and compare placental protein and mRNA levels from GDM with macrosomia group (GDMM), GDM with normal birth weight group (GDMN) and normal glucose tolerance (NGT) with normal birth weight group (CON). Western blotting was performed to examine differentially expressed proteins of caveolin-1 (Cav-1) and Adenosine monophosphate-activated protein kinase (AMPK) signaling pathway related proteins, including phosphorylated-AMPKα(Thr172), AMPKα, phosphorylated-Acetyl-CoA carboxylase(Ser79) (p-ACC(Ser79)), ACC and glucose transporter 1 (GLUT1) in placenta between the three groups. The mRNA levels of Cav-1, AMPKα, ACC and GLUT1 in placenta were measured by real time-PCR.

Results

In the GDMM placenta group, both protein and mRNA levels of Cav-1 were down-regulated, while GLUT1 was up-regulated; the phosphorylation and mRNA levels of ACC and AMPKα were decreased, but total ACC protein levels were increased compared to both the GDMN (p<0.05) and CON groups (p<0.05). In GDMM placenta group, there was a significant negative correlation observed between neonatal birth weight (NBW) and protein expression levels of Cav-1, p-ACC(Ser79) and p-AMPKα(Thr172) (p<0.05), while positive relationship with ACC and GLUT1 protein levels. Besides, in GDMM group placental mRNA levels, NBW had a positive correlation with GLUT1 (p<0.05), while negative with Cav-1, AMPKα and ACC expression (p<0.05). Cav-1 protein expression was positively associated with p-AMPK and p-ACC (p<0.05), and negatively associated with GLUT1 (p<0.05). Interestingly, p-AMPK protein expression was closely related to p-ACC (p<0.05), but not with GLUT1.

Conclusion

GDM-induced macrosomias have more severe inhibition of Cav-1 expression in placenta. Cav-1 is associated with placental glucose and fatty acid transport via the induction of AMPK signaling pathway and the reduction of GLUT1 signaling pathway to reverse GDM-induced macrosomia.

Testosterone Deficiency Induces Changes of the Transcriptomes of Visceral Adipose Tissue in Miniature Pigs Fed a High-Fat and High-Cholesterol Diet

Testosterone deficiency causes fat deposition, particularly in visceral fat, and its replacement might reverse fat accumulation, however, the underlying mechanisms of such processes under diet-induced adiposity are largely unknown. To gain insights into the genome-wide role of androgen on visceral adipose tissue (VAT), RNA-Seq was used to investigate testosterone deficiency induced changes of VAT in miniature pigs fed a high-fat and high-cholesterol (HFC) diet among intact male pigs (IM), castrated male pigs (CM), and castrated male pigs with testosterone replacement (CMT) treatments. The results showed that testosterone deficiency significantly increased VAT deposition and serum leptin concentrations. Moreover, a total of 1732 differentially expressed genes (DEGs) were identified between any two groups. Compared with gene expression profiles in IM and CMT pigs, upregulated genes in CM pigs, i.e., LOC100520753 (CD68), LCN2, EMR1, S100A9, NCF1 (p47phox), and LEP, were mainly involved in inflammatory response, oxidation-reduction process, and lipid metabolic process, while downregulated genes in CM pigs, i.e., ABHD5, SPP1, and GAS6, were focused on cell differentiation and cell adhesion. Taken together, our study demonstrates that testosterone deficiency alters the expression of numerous genes involved in key biological processes of VAT accumulation under HFC diet and provides a novel genome-wide view on the role of androgen on VAT deposition under HFC diet, thus improving our understanding of the molecular mechanisms involved in VAT changes induced by testosterone deficiency.