Darija Šnajder

High-fat diet induced changes in lumbar vertebra of the male rat offsprings

In obesity, bone marrow adiposity increases and proinflammatory cytokines excretion activates RANK/RANKL/OPG system, which leads to increased bone resorption. The aim of this study was to analyze trabecular and cortical bone parameters in animals exposed to the high-fat diet in utero and after lactation. Skeletal organ of interest was the fifth lumbar vertebra, which is not exposed to biomechanical loading in rats. Further aims were to determine TNF-α and IL-6 serum concentrations, and the intensity of the TNF-α immunohistochemical staining in the bone marrow. Ten female Sprague Dawley rats, nine weeks old, were randomly divided in two groups and fed either standard laboratory chow or food rich in saturated fatty acids during five weeks, and then mated with genetically similar male subjects. After birth and lactation male offsprings from both groups were divided in four subgroups depending on the diet they were fed until twenty-two weeks of age. The highest cholesterol and triglyceride concentration were found in both groups of offsprings fed with high-fat diet. The lowest trabecular bone volume, lowest trabecular number and highest trabecular separation were found in offsprings fed with high-fat diet of mothers on standard laboratory chow. The same group of offsprings was also characterized by the highest intensity of TNF-α immunostaining in the bone marrow and the highest TNF-α serum concentration, which suggest that this proinflammatory cytokine has interfered with bone metabolism, possibly by stimulation of bone resorption, which led to inadequate trabecular bone development and bone modeling of the fifth lumbar vertebra.

Effect of different combination of maternal and postnatal diet on adipose tissue morphology in male rat offspring

Abstract Purpose: Adipose tissue expansion can occur through several different ways and, under certain conditions, can be connected with chronic inflammation. TNF-α is one of the important cytokines involved in this process. Prolonged inflammation in obesity can lead to obesity-related insulin resistance and tissue dysfunction. The aim of our study was to investigate how different combination of maternal and postnatal diet affects offspring adipose tissue morphology and adipose tissue TNF-α expression. Methods: Ten female Sprague Dawley rats, 9 weeks old, were randomly divided into two groups and fed either standard laboratory chow or food rich in saturated fatty acids during 6 weeks and then mated with the same male rat. After birth and lactation male rat offspring from both groups were divided into four subgroups depending on the diet they were fed until 22 weeks old. Samples of white adipose tissue were taken from the subcutaneous, epididymal, and perirenal fat pad. On tissue sections, histomorphometric analysis was conducted using CellProfiler program v 2.1.1, and immunohistochemical staining for TNF-α was performed. Results: Greater mean surface area of subcutaneous and epididymal adipocytes was found in groups of male rat offspring with altered diet. In perirenal adipose tissue, the highest number of adipocytes was measured in the group where both mother and offspring were fed a high-fat diet. Adipocyte staining intensity for TNF-α did not differ significantly between the groups. Conclusions: Together with our previously published data, our results lead to the conclusion that alteration of postnatal diet can lead to TNF-α and adipocyte morphology changes.

Different combinations of maternal and postnatal diet are reflected in changes of hepatic parenchyma and hepatic TNF-alpha expression in male rat offspring

Obesity is related to increased TNF-alpha production in different tissues. TNF-alpha is connected to mitochondrial dysfunction in the liver and also development of fatty infiltration of the liver. Also, postnatal change from normal to high-fat diet causes a significant increase in TNF-alpha serum levels. The aim of this research was to determine how maternal diet and switching male offspring to a different dietary regime after lactation influences rat liver. Ten female Sprague Dawley rats at nine weeks of age were randomly divided in two groups and fed either standard laboratory chow or high-fat diet during six weeks, and then mated with the same male subject. After birth and lactation male offspring from both groups were further divided into four subgroups depending on their subsequent diet. At 22 weeks of age, the animals were weighted, sacrificed and major organs were collected and weighted. Immunohistochemistry for TNF-alpha was performed on liver, and liver samples were analyzed for pathohistological changes. The group in which mothers were fed standard chow and offspring high-fat diet had the most pronounced changes: heaviest liver, poorest histopathological findings and strongest TNF-alpha immunohistochemical staining of liver parenchyma. High-fat diet during pregnancy and lactation and switching to high-fat diet postnatally affects liver weight, histological structure and TNF-alpha expression in male offspring.