Browsing by Author "Labudović-Borović, Milica (36826154300)"

Background/Aim. A substantial line of evidence indicates that Kv4.2 and Kv4.3 channels are the major components of rapid transient-outward potassium currents (A-type currents). It is speculated that those currents may be involved in the maintenance of the membrane potential, as well as in the regulation of propagation and frequency of action potentials. However, very little is known about the presence and function of A-type currents in human vascular smooth muscles such as the human umbilical vein (HUV). Bearing in mind its crucial role in the proper fetal oxygenation, the aim of the study was to determine whether Kv4.2 and Kv4.3 potassium channels are present in HUV smooth muscle and to investigate potential alterations of their expression during maternal pathological conditions such as gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH). Methods. Healthy, diabetic, and hypertensive pregnancies were subjects of this investigation. Each group consisted of 6 HUV samples obtained from 6 normal pregnancies, 6 pregnancies with GDM, and 6 with PIH. After pharmacology analysis, immunohistochemistry (IH) and Western blot were performed. Results. IH revealed similar expression patterns of both, Kv4.2 and Kv4.3 subunits in HUV smooth muscle in all groups of patients. Results obtained by Western blot were in agreement with IH staining. The expression of Kv4.2 and Kv4.3 subunits were not significantly different between the groups. Conclusion. Collectively, this is the first study that demonstrated the presence of Kv4.2 and Kv4.3 potassium channels in the HUV smooth muscle and their preservation during GDM and PIH pregnancies. These channels are most likely major components of rapid A-type currents that may be relevant for maternal-fetus blood flow and hence fetal development. In addition, they may represent sensors for detecting hemodynamic and/or metabolic changes in the local environment. © 2023 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.

We have already shown that metallophilic macrophages, which represent an important component in the thymus physiology, are lacking in lymphotoxin-β receptor-deficient mice. However, further molecular requirements for the development and correct tissue positioning of these cells are unknown. To this end, we studied a panel of mice deficient in different chemokine ligand or receptor genes. In contrast to normal mice, which have these cells localized in the thymic cortico-medullary zone (CMZ) as a distinct row positioned between the cortex and medulla, in plt/plt (paucity of lymph node T cells) mice lacking the functional CCL19/CCL21 chemokines, metallophilic macrophages are not present in the thymic tissue. Interestingly, in contrast to the CCL19/21-deficient thymus, metallophilic macrophages are present in the CCR7-deficient thymus. However, these cells are not appropriately located in the CMZ, but are mostly crowded in central parts of thymic medulla. The double staining revealed that these metallophilic macrophages are CCR7-negative and CXCR3-positive. In the CXCL13-deficient thymus the number, morphology and localization of metallophilic macrophages are normal. Thus, our study shows that CCL19/21 and its possible signaling through CXCR3 are required for the development of thymic metallophilic macrophages, whereas the CXCL13-CXCR5 signaling is not necessary. © 2011 Springer-Verlag.

We have already shown that metallophilic macrophages, which represent an important component in the thymus physiology, are lacking in lymphotoxin-β receptor-deficient mice. However, further molecular requirements for the development and correct tissue positioning of these cells are unknown. To this end, we studied a panel of mice deficient in different chemokine ligand or receptor genes. In contrast to normal mice, which have these cells localized in the thymic cortico-medullary zone (CMZ) as a distinct row positioned between the cortex and medulla, in plt/plt (paucity of lymph node T cells) mice lacking the functional CCL19/CCL21 chemokines, metallophilic macrophages are not present in the thymic tissue. Interestingly, in contrast to the CCL19/21-deficient thymus, metallophilic macrophages are present in the CCR7-deficient thymus. However, these cells are not appropriately located in the CMZ, but are mostly crowded in central parts of thymic medulla. The double staining revealed that these metallophilic macrophages are CCR7-negative and CXCR3-positive. In the CXCL13-deficient thymus the number, morphology and localization of metallophilic macrophages are normal. Thus, our study shows that CCL19/21 and its possible signaling through CXCR3 are required for the development of thymic metallophilic macrophages, whereas the CXCL13-CXCR5 signaling is not necessary. © 2011 Springer-Verlag.