Localization of alpha-casein gene transcription in sections of epoxy resin-embedded mouse mammary tissues by in situ hybridization

Transgenic expression of an altered angiotensin type I AT1 receptor resulting in marked modulation of vascular type I collagen

The angiotensin II (AngII) type I receptor (AT1) was modified by replacing its third intracellular loop and C-terminal tail with the corresponding regions from the bradykinin B2 receptor. Transgenic mice were produced that overexpress this mutated receptor (AB3T). Considerably less collagen content in the intact aorta and in primary aortic smooth muscle cells (aSMCs) cultures was observed in the transgenic mice. On the other hand, elastin content remained unchanged as measured by Western blot, and insoluble amino acid quantitation. The contraction of isolated aortas also remained unaltered. The aSMCs derived from the transgenic mice showed a reduction in AngII responsive type I collagen production. In aSMCs from transgenic mice, the cascade of Akt to the mammalian target rapamycin (mTOR) to p70 S6 kinase (p70S6K) was not AngII activated, while in the aSMCs from wild-type (WT) mice the cascade was AngII activated. Angiotensin activation of Smad2 and Stat3 was also reduced in the AB3T aSMCs. However, no change in the effect of transforming growth factor β (TGFβ) on type I collagen production was observed. Also, the activation of ERK and JNK and G-protein linked signaling remained unaltered in response to AngII. Akt and PI3K activation inhibitors blocked AngII-stimulated type I collagen expression in WT aSMCs, whereas ERK inhibitor had no such effect. Our results point to an Akt/mTOR/p70S6K regulation of collagen production by AngII with participation of Smad2 and Stat3 cascades in this process.

Baby on board: do responses to stress in the maternal brain mediate adverse pregnancy outcome?

Stress and adverse environmental surroundings result in suboptimal conditions in a pregnant mother such that she may experience poor pregnancy outcome including complete pregnancy failure and preterm labor. Furthermore her developing baby is at risk of adverse programming, which confers susceptibility to long term ill health. While some mechanisms at the feto-maternal interface underlying these conditions are understood, the underlying cause for their adverse adaptation is often not clear. Progesterone plays a key role at many levels, including control of neuroendocrine responses to stress, procuring the required immune balance and controlling placental and decidual function, and lack of progesterone can explain many of the unwanted consequences of stress. How stress that is perceived by the mother inhibits progesterone secretion and action is beginning to be investigated. This overview of maternal neuroendocrine responses to stress throughout pregnancy analyses how they interact to compromise progesterone secretion and precipitate undesirable effects in mother and offspring.

In situ hybridization: optimization of the techniques for collecting and fixing the specimens

An overview is presented concerning the different protocols for collecting and fixing the specimens for in situ hybridization analysis. Particular attention is devoted to the problem of avoiding the tissue RNA degradation due to the ubiquitous and rather resistant RNases. The choice of the final protocol largely depends on a compromise between the need to maintain morphological details, the care to avoid loss of the target nucleic acids and the capability of the probe to diffuse within the specimen.

Application of the immunogold-silver staining method to localize a mammary-derived growth inhibitor

Distribution of a growth inhibitor in mammary tissue of cow and mouse was described by means of immunogold-silver stained semithin Lowicryl- and cryosections. In pregnant and lactating state of the tissue, remarkable amounts of the growth regulating protein of 1r = 13,000 could be detected mainly in epithelial cells.

Transforming growth factor-alpha messenger RNA localization in the developing adult rat and human mammary gland by in situ hybridization

Transforming growth factor-alpha (TGF alpha) has been implicated in the autocrine growth control of a number of different rodent and human tumor cells, including breast cancer cells. Although TGF alpha has been detected in a limited number of normal tissues, its distribution and physiological function in the mammary gland are relatively unknown. TGF alpha mRNA expression was detected by in situ hybridization with a labeled TGF alpha antisense RNA probe and quantitated by application of computer-assisted digital image processing in both the ductal and alveolar epithelial cells in the virgin rat and nulliparous and parous human mammary glands. During pregnancy and lactation, the level of TGF alpha mRNA expression in the ductal and alveolar epithelial cells increased two- to threefold, while a heterogeneous yet strong expression of TGF alpha mRNA could also be detected in approximately 10-15% of the surrounding stromal cells in the pregnant mammary gland.