The Effects of Whole Body Gamma Irradiation on Mice, Age-Related Behavioral, and Pathophysiological Changes.

We designed a study with the objective to determine the long-term radiation effects of gamma rays, originating from a single shot of Co60 at a dose of 2 Gy on the 7-month-old male mice of the ICR line in 30 days after the irradiation. The aim of this study was to characterize the behavior of animals using the Open Field test, immuno-hematological status, and morpho-functional changes in the central nervous system of mice. Irradiated animals displayed significantly different behavior in the OF in comparison with the control group. The radiation damage was confirmed by assessing the ratio of leukocytes in the peripheral blood of mice at a later date after exposure to Co60. After irradiation, a decrease in the glioneuronal complex was observed in the irritated group as well as histological changes of brain cells. To sum up, not only was the hematological status of mice altered upon the total gamma irradiation, but also their behavior, which was most probably due to significant alterations in the CNS. Study of influence of ionizing radiation on female mice, comparison between different age groups. Open Field test on the 30 days after 2 Gy of γ-rays and histological analysis indicated changes in behavioral patterns, leucocytes, and brain tissue.

Altered organization of collagen fibers in the uninvolved human colon mucosa 10 cm and 20 cm away from the malignant tumor.

Remodelling of collagen fibers has been described during every phase of cancer genesis and progression. Changes in morphology and organization of collagen fibers contribute to the formation of microenvironment that favors cancer progression and development of metastasis. However, there are only few data about remodelling of collagen fibers in healthy looking mucosa distant from the cancer. Using SHG imaging, electron microscopy and specialized softwares (CT-FIRE, CurveAlign and FiberFit), we objectively visualized and quantified changes in morphology and organization of collagen fibers and investigated possible causes of collagen remodelling (change in syntheses, degradation and collagen cross-linking) in the colon mucosa 10 cm and 20 cm away from the cancer in comparison with healthy mucosa. We showed that in the lamina propria this far from the colon cancer, there were changes in collagen architecture (width, straightness, alignment of collagen fibers and collagen molecules inside fibers), increased representation of myofibroblasts and increase expression of collagen-remodelling enzymes (LOX and MMP2). Thus, the changes in organization of collagen fibers, which were already described in the cancer microenvironment, also exist in the mucosa far from the cancer, but smaller in magnitude.

Tumour necrosis factor receptor-1 is dispensable for the migration of marginal metallophilic macrophages into the B-cell zone of the mouse spleen.

The spleen is the only blood filter in the organism which removes foreign antigens and effete cells from circulation. The significant role in capturing, transporting and presentation of antigens to immune cells is executed by a special subset of splenic macrophages called marginal metallophilic macrophages. Upon stimulation with lipopolysaccharide, these cells promptly migrate from their preferential location at the inner aspect of the splenic marginal sinus into the B-cell lymphoid follicles. This migration is executed via CXC chemokine ligand 13 in a lymphotoxin-dependent fashion. However, the role of tumour necrosis factor-α/tumour necrosis factor receptor-1 signalling axis has not been studied, despite its critical role in the formation of B-cell lymphoid follicles, follicular dendritic cell networks and germinal centres. Here, we show that signalling via tumour necrosis factor receptor-1 is not required for the migration of marginal metallophilic macrophages into the B-cell zone and that the presence of organized B-cell lymphoid follicles is not a prerequisite for their dislocation.

Lipopolysaccharide induces tumor necrosis factor receptor-1 independent relocation of lymphocytes from the red pulp of the mouse spleen.

It is well known that bacterial lipopolysaccharide (LPS) induces migration of several cellular populations within the spleen. However, there are no data about the impact of LPS on B and T lymphocytes present in the red pulp. Therefore, we used an experimental model in which we tested the effects of intravenously injected LPS on the molecular, cellular and structural changes of the spleen, with special reference to the red pulp lymphocytes. We discovered that LPS induced a massive relocation of B and T lymphocytes from the splenic red pulp, which was independent of the tumor necrosis factor receptor-1 signaling axis. Early after LPS treatment, quantitative real-time PCR analysis revealed the elevated levels of mRNA encoding numerous chemokines and proinflammatory cytokines (XCL1, CXCL9, CXCL10, CCL3, CCL4, CCL5, CCL17, CCL20, CCL22, TNFα and LTα) which affect the navigation and activities of B and T lymphocytes in the lymphoid tissues. An extreme increase in mRNA levels for CCL20 was detected in the white pulp of the LPS-treated mice. The CCL20-expressing cells were localized in the PALS. Some smaller CCL20-expressing cells were evenly dispersed in the B cell zone. Thus, our study provides new knowledge of how microbial products could be involved in shaping the structure of lymphatic organs.

Remodeling of extracellular matrix of the lamina propria in the uninvolved human rectal mucosa 10 and 20 cm away from the malignant tumor.

In recent years, it has been demonstrated that malignancy arises and advances through the molecular interplay between tumor cells and non-malignant elements of the tumor stroma, that is, fibroblasts and extracellular matrix. However, in contrast to the mounting evidence about the role of tumor stroma in the genesis and progression of the malignant disease, there are very few data regarding the uninvolved stromal tissue in the remote surrounding of the tumor. Using the objective morphometric approach in patients with adenocarcinoma, we demonstrate the remodeling of extracellular matrix of the lamina propria in the uninvolved rectal mucosa 10 and 20 cm away from the neoplasm. We show that the representation of basic extracellular matrix constituents (reticular and collagen fibers and ground substance) is decreased. Also, the diameter of empty spaces that appear within the extracellular matrix of the lamina propria is increased. These spaces do not represent the blood or lymphatic vessel elements. Very likely, they reflect the development of tissue edema in the remote, uninvolved lamina propria of the mucosa in patients with the malignant tumor of the rectum. We hypothesize that the remodeling of extracellular matrix in lamina propria of the rectal mucosa may increase its stiffness, modulating the mechano-signal transduction, and thus promote the progression of the malignant disease.

Aberrant tissue positioning of metallophilic macrophages in the thymus of XCL1-deficient mice.

Metallophilic macrophages hold a strategic position within the thymic tissue and play a considerable function in thymic physiology. The development and positioning of these cells within thymic tissue are regulated by complex molecular mechanisms involving different cytokine/chemokine axes. Herein, we studied the role of XCL1 signaling in these processes. We show that in the XCL1-deficient thymus numerous metallophilic macrophages are aberrantly positioned in the thymic cortex, instead of their normal location in the cortico-medullary zone. Still, these cells retain their normal appearance: very large size with prominent, ramifying cytoplasmic prolongations. This shows that XCL1 signaling is not involved in morphological development, but rather in correct positioning of metallophilic macrophages within the thymic tissue. In contrast to thymic metallophilic macrophages, the positioning of splenic marginal metallophilic macrophages is not affected by XCL1-deficiency.

Morphometric study of uninvolved rectal mucosa 10 cm and 20 cm away from the malignant tumor.

Recently, many details of the interplay between tumor cells and tumor-associated stromal elements leading to the progression of malignant disease were elucidated. In contrast, little is known about the role of uninvolved stromal tissue in the remote surrounding of the malignant tumor. Therefore, we performed a computer-aided morphometric study of rectal mucosa in samples taken 10 cm and 20 cm away from the malignant tumor during endoscopic examination of 23 patients older than 60 years. The samples of rectal mucosa from 10 healthy persons of corresponding age subjected to diagnostic rectoscopy during active screening for asymptomatic cancer were used as control. All structural elements of the rectal mucosa were studied and the number of nucleated cells in the lamina propria per 0.1 mm² of tissue was assessed. Our study revealed a reduced number of cells in the lamina propria of the rectal mucosa 10 cm and 20 cm away from the tumor lesion in both male and female patients. The decreased mucosal height and increased crypt number were registered in female patients 10 cm away from the tumor. The connective tissue of lamina propria showed a disorderly organization: the collagen fibers were frail, loosely arranged and signs of tissue edema were present. Small blood vessels and capillaries were much more frequently seen than in healthy tissue. Our results demonstrate the complex interactions between the cancer and remote mucosal tissue of the affected organ.