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Immune aggression to transplanted allogeneic bone marrow, i.e. the graft-versus-host disease (GVHD), could be decreased by the suppression of effector and/or activation of T-regulatory cells (Тreg). This task could be solved by co-transplantaiton of allogeneic bone marrow and mesenchymal stromal cells (MSCs). This study demonstrated the elevated immune modulating activity of MSCs by their culturing in vitro on Al 2 O 3 oxide nanocoatings. Introduction of the cells to the animals with GVHD resulted in an increased content of Treg in the spleen of bone marrow recipients, reduced severity of the pathology, and higher survival of animals. The findings could be the basis for developing the new approaches to optimize the GVHD treatment methods involving the oxide nanocoating cultured MSCs.

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Neurotensin (NT) and neuromedin N (NN) are generated by endoproteolytic cleavage of a common precursor molecule, pro-NT/NN. To gain insight into the role of prohormone convertases PC1, PC2, and PC7 in this process, we investigated the maturation of pro-NT/NN in the brain of PC7 (PC7)/-), PC2 (PC2-/-), and/or PC1 (PC1+/-and PC2-/-; PC1+/-) knock down mice. Inactivation of the PC7 gene was without effect, suggesting that this convertase is not involved in the processing of pro-NT/NN. By contrast, there was a 15% decrease in NT and a 50% decrease in NN levels, as measured by radioimmunoassay, in whole brain extracts from PC2 null as compared with wild type mice. Using immunohistochemistry, we found that this decrease in pro-NT/NN maturation products was uneven and that it was most pronounced in the medial preoptic area, lateral hypothalamus, and paraventricular hypothalamic nuclei. These results suggest that PC2 plays a critical role in the processing of pro-NT/NN in mouse brain and that its deficiency may be compensated to a regionally variable extent by other convertases. Previous data have suggested that PC1 might be subserving this role. However, there was no change in the maturation of pro-NT/NN in the brain of mice in which the PC1 gene had been partially inactivated, implying that complete PC1 knock down may be required for loss of function.

The neuropeptides/neurotransmitters neurotensin (NT) and neuromedin (NN) are synthesized by endoproteolytic cleavage of a common inactive precursor, pro-NT/NN. In vitro studies have suggested that the prohormone convertases PC5A and PC2 might both be involved in this process. In the present study, we used dual immunohistochemical techniques to determine whether either one or both of these two convertases were co-localized with pro-NT/NN maturation products and could therefore be involved in the physiological processing of this propeptide in rat brain. PC2-immunoreactive neurons were present in all regions immunopositive for NT. All but three regions expressing NT were also immunopositive for PC5A. Dual localization of NT with either convertase revealed that NT was extensively co-localized with both PC5A and PC2, albeit with regional differences. These results strongly suggest that PC5A and PC2 may play a key role in the maturation of pro-NT/NN in mammalian brain. The regional variability in NT/PC co-localization patterns may account for the region-specific maturation profiles previously reported for pro-NT/NN. The high degree of overlap between PC5A and PC2 in most NT-rich areas further suggests that these two convertases may act jointly to process pro-NT/NN. At the subcellular level, PC5A was largely co-localized with the mid-cisternae Golgi marker MG-160. By contrast, PC2 was almost completely excluded from MG-160-immunoreactive compartments. These results suggest that PC5A, which is particularly efficient at cleaving the two C-terminal-most dibasics of pro-NT/NN, may be acting as early as in the Golgi apparatus to release NT, whereas PC2, which is considerably more active than PC5A in cleaving the third C-terminal doublet, may be predominantly involved further distally along the secretory pathway to release NN.

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Biochemical studies have shown that prohormone convertases PC1, PC2 and PC5A all have the capacity to process, with different specificities, the neurotensin/neuromedin N precursor, pro-NT/NN. A previous study from our laboratory has demonstrated that in rat brain, both PC2 and PC5A may be co-expressed with NT, lending support to a physiological implication of these two enzymes in the endoproteolytic maturation of pro-NT/NN. In the present study, we sought to determine whether PC1 might also be involved in this process by comparing the immunohistochemical distribution of the enzyme with that of NT in both singly labeled and dually labeled serial brain sections. PC1 was found to co-localize extensively with NT throughout the rat neuraxis. However, there were important regional variations in the proportion of NT neurons co-expressing PC1. Furthermore, this proportion was negatively correlated with that of NT neurons expressing PC5, suggesting that PC1 may serve as an alternative to PC5A for processing pro-NT/NN in mammalian brain.