Effect of maternal apical periodontitis on the final step of insulin signalling and inflammatory pathway in the adult male offspring of rats.

AIM: To evaluate the final step of insulin signalling, inflammatory pathway (related to the inhibition of insulin signalling), peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) protein content and DNA methylation in the Slc2a4 gene promoter region in the skeletal muscle of adult male offspring of rats with apical periodontitis (AP) in a single tooth or in four teeth. METHODOLOGY: Female Wistar rats were distributed into three groups: a control group, a group with one tooth with AP and a group with four teeth with AP. Thirty days after induction of AP, female rats from all groups were mated with healthy male rats. When male offspring reached 75 days of age, the following analyses were performed in the gastrocnemius muscle (GM): insulin-stimulated Akt serine and threonine phosphorylation status; NF-κB p50 and p65 subunits phosphorylation status; GLUT4, TNF-α and PGC-1α protein content by Western blotting; GLUT4 and TNF-α gene expression by real-time polymerase chain reaction (PCR); and DNA methylation in the Slc2a4 gene promoter region by restriction digestion and real-time PCR. Analysis of variance was performed, followed by Tukey's post hoc test. p values <.05 were considered to be statistically significant. RESULTS: Maternal AP in four teeth decreased insulin-stimulated Akt serine and threonine phosphorylation status, reduced GLUT4 gene expression and its protein content, and increased NF-κB p50 and p65 subunits phosphorylation status in the GM of adult offspring. There were no alterations in the parameters analysed in the GM of adult offspring of rats with AP in a single tooth. In addition, maternal AP did not affect TNF-α gene expression and its protein content, PGC-1α protein content and DNA methylation in the Slc2a4 gene promoter region in the GM of adult offspring. CONCLUSIONS: Maternal AP in four teeth was associated with impairment in the final step of insulin signalling in the GM of adult male offspring in rats. An increase in NF-κB activity may be involved in this decrease in insulin signalling. This study demonstrates the impact of maternal AP on the health of offspring, demonstrating the importance of maintaining adequate maternal oral health to prevent diseases in adult offspring in rats.

Maternal apical periodontitis is associated with insulin resistance in adult offspring.

AIM: To investigate the plasma concentrations of glucose, insulin and tumour necrosis factor-α (TNF-α) of rats with maternal apical periodontitis (AP) and to explore the effect of maternal inflammation on the initial steps of insulin signalling and the inflammatory pathway in the gastrocnemius muscle (GM) and periepididymal white adipose tissue (pWAT) of adult offspring. METHODOLOGY: Fifteen female Wistar rats were distributed into a control group (CN), a group with 1 tooth with AP (1AP) and a group with 4 teeth with AP (4AP). Thirty days following induction of AP, female rats from all groups were mated with healthy male rats. When male offspring reached 75 days of age, plasma concentrations of glucose, insulin and TNF-α were quantified. Insulin resistance was evaluated by the homoeostasis model assessment of insulin resistance (HOMA-IR) index. Phosphorylation status of pp185 tyrosine, insulin receptor substrate 1 (IRS-1) serine, IκB kinase α/ß (IKKα/ß) and c-Jun N-terminal kinase (JNK) in the GM and pWAT were measured by Western blot. Analysis of variance was performed, followed by the Tukey's post hoc test. P values <0.05 were considered to be statistically significant. RESULTS: Maternal AP promoted insulin resistance, impaired the initial steps of insulin signalling, significantly increased plasma concentrations of insulin (P < 0.001) and TNF-α (P < 0.05), and enhanced IKKα/ß phosphorylation in the GM and pWAT (P < 0.05) of adult offspring. However, maternal AP did not affect fasting glycaemia and JNK phosphorylation in the GM and pWAT of adult offspring. CONCLUSIONS: Maternal AP was associated with insulin resistance in adult offspring through alterations in insulin signalling and inflammation pathways. The study provides information on the impact of maternal AP on the development of metabolic alterations such as insulin resistance in adult offspring and reinforces the importance of preventing maternal AP in order to maintain the general health of offspring.

Acoustic radiation force impulse (ARFI) elastography to asses maternal and foetal structures in pregnant ewes.

The aim of this study was to evaluate the stiffness of foetal lungs, liver, kidneys and placentomes by acoustic radiation force impulse (ARFI) elastography in ovine and to correlate obtained findings with foetal development. Twenty-four ewes were included, and tissue stiffness of foetal lung, liver, kidney and placentome was measured beginning with 10th gestational week by qualitative-quantitative ARFI elastography. A total of 33 healthy lambs were born. Qualitative elastographic analysis permitted to classify maternal and foetal tissues elasticity in decreasing order as follows: placentome, kidney, liver and lung. Regarding quantitative ARFI elastography data, shear wave velocity (SWV) of foetal lung and liver varied. The lung SWV decreased gradually from the 16th to the 21st gestational week (R2  = 0.80; p < 0.001), while liver SWV increased gradually from the 14th to 21st gestational week (R2  = 0.80; p < 0.001). In contrast, the kidneys and placentomes SWV's remained constant through gestation (p = 0.076; and 0.34). ARFI elastography was shown feasible for evaluation of maternal and foetal tissues stiffness in the ovine model. It can be used to demonstrate pulmonary and hepatic stiffness modifications during foetal development.

Qualitative and quantitative ultrasound attributes of maternal-foetal structures in pregnant ewes.

The aim of this study was to examine foetal organs and placental tissue to establish a correlation between the changes in the composition of these structures associated with their maturation and the ultrasonographic characteristics of the images. Twenty-four pregnant ewes were included in the study. Ultrasonography assessments were performed in B-mode, from the ninth gestational week until parturition. The lungs, liver and kidneys of foetuses and placentomes were located in transverse and longitudinal sections to evaluate the echogenicity (hypoechoic, isoechoic, hyperechoic or mixed) and echotexture (homogeneous and heterogeneous) of the tissues of interest. For quantitative evaluation of the ultrasonographic characteristics, it was performed a computerized image analysis using a commercial software (Image ProPlus® ). Mean numerical pixel values (NPVs), pixel heterogeneity (standard deviation of NPVs) and minimum and maximum pixel values were measured by selecting five circular regions of interest in each assessed tissue. All evaluated tissues presented significant variations in the NPVs, except for the liver. Pulmonary NPVmean, NPVmin and NPVmax decreased gradually through gestational weeks. The renal parameters gradually decreased with the advancement of the gestational weeks until the 17th week and later stabilized. The placentome NPVmean, NPVmin and NPVmax decreased gradually over the course of weeks. The hepatic tissue did not show echogenicity and echotexture variations and presented medium echogenicity and homogeneous echotexture throughout the experimental period. It was concluded that pixels numerical evaluation of maternal-foetal tissues was applicable and allowed the identification of quantitative ultrasonographic characteristics showing changes in echogenicity related to gestational age.

Maternal Na+ intake induces renal function injury in rats prevented by a short-term angiotensin converting enzyme inhibitor.

The Na+ -ATPase, a secondary pump in the proximal tubule, is only weakly responsive to angiotensin II in adult offspring exposed perinatally to high Na+ intake. We have investigated whether the offspring from mothers given 0.3 mol/L NaCl show an ineffective angiotensin II action to increase in blood pressure. It was hypothesized that functional alterations at adult life are associated with the number of angiotensin II-positive cells in the developing kidney, with increased oxidative stress in maternal/foetal organs, or with morphometrical changes in placentas. Wistar female rats were maintained on 0.3 mol/L NaCl in their drinking water from 20 days before conception until weaning. After weaning, some of the male offspring were treated with enalapril for 21 days. Glomerular filtration rate was recorded up to 210 days of age, when mean arterial pressure was measured after infusion of angiotensin II. To investigate the placenta and foetal kidneys, mothers on tap water or NaCl were also treated with alpha-tocopherol, pregnancy being interrupted on the 20th day. There were no changes in the number of cells positive for angiotensin II in the foetal kidney and unchanged lipid peroxidation in the placenta of offspring exposed to NaCl, but the intermediate trophoblast area in the junctional zone was increased, possibly reducing maternal-foetal exchange. Glomerular filtration rate was reduced and there was an attenuated effect of angiotensin II on elevation of blood pressure, which could be mediated by an elevated angiotensin II during early life, once these disturbances had been prevented by early and short-term treatment with enalapril.

Variation in the number of ovarian follicles in cattle: possible causes and consequences

Background: Antral follicle count (AFC, follicles e"3 mm in diameter) varies between 5 and 50 follicles in among Bos taurus cattle. AFC is highly repeatable within animals, and is correlated with the total number of follicles in ovaries. Cattle with low AFC have higher circulating concentrations of FSH and LH, but lower concentrations of AMH, progesterone and androgens than animals with high AFC. Review: The cause of the inherently high variation in the number of follicles is unknown but it is reasonable to speculate that maternal nutrition during gestation, at the time of ovarian development in their foetuses, may impact oogonia proliferation and thus follicle numbers postnatally. We have recently started to test this hypothesis by restricting nutrition of beef heifers to 0.6 of their maintenance energy requirements, from shortly before conception to the end of the first trimester of pregnancy (period encompassing the peak in oocyte numbers in foetuses). Results show that calves born to nutritionally restricted mothers have a 60% lower peak, minimum and mean AFC during follicular waves compared with calves born to mothers fed control diets. Interestingly these calves from restricted mothers also had higher blood pressure compared to controls. Additional studies also provide evidence to suggest that fertility may be compromised in animals with low AFC due to effects on oocytes, progesterone and the endometrium compared to animals with high AFC. To test this hypothesis we performed ovarian ultrasonography on 306 dairy cows during the first wave of follicular development 1 to 4 months post partum and recorded their reproductive performances during the breeding season; cows with a high AFC had higher pregnancy rates, shorter calving to conception intervals and received fewer services during the breeding season compared to cows with a low AFC. Conclusion: Recent studies suggest that the numbers of follicles in follicle waves, and in total in the ovaries, may now be an important consideration for further efforts to understand and manipulate fertility. Since ovarian follicle numbers are reflective of the environment during foetal development when all the organ systems are developing, altered follicle numbers may also be reflective of other developmental difference in organs that may have more profound effects on the animals health and welfare beyond effects on reproduction and fertility.