Weissella paramesenteroides WpK4 ameliorate the experimental amoebic colitis by increasing the expression of MUC-2 and the intestinal epithelial regeneration.

AIMS: This study evaluates the action of Weissella paramesenteroides WpK4 on amoebic colitis. METHODS AND RESULTS: Weissella paramesenteroides WpK4 was administered in Entamoeba dispar infected and noninfected mice and clinical parameters were evaluated. Following 7 days, the caeca were collected for histopathology, morphometry and immunohistochemical staining of MUC-2, CDC-47 and IgA. The treatment reduced diarrhoea and the presence of blood in the faeces and diminished the area of necrosis, also causing weight gain. Also, the addition of this bacterium enhanced the expression of the mucin (MUC-2). The reduction in necrosis and increased CDC-47 expression indicates significant epithelial regeneration. The negative correlation between CDC-47 and the necrosis area reveals that the bacterium favoured the recovery of the necrotic regions and the positive correlation found between the expression of MUC-2 and CDC-47 indicates that the epithelial regeneration also supports the synthesis of MUC-2. CONCLUSIONS: Weissella paramesenteroides WpK4 was able to increase the protection of the intestinal mucosa against experimental amoebic colitis through the increase of MUC-2 and epithelial regeneration. SIGNIFICANCE AND IMPACT OF THE STUDY: Weissella paramesenteroides WpK4 presents the potential to become a complementary tool in the treatment of amoebic colitis.

Profile of cell proliferation and apoptosis activated by the intrinsic and extrinsic pathways in the prostate of aging rats.

BACKGROUND: Estrogens acting through the receptors ERα and ERß participate in prostate normal growth and cancer. ERß is highly expressed in the prostate epithelium, playing pro-apoptotic, anti-proliferative, and pro-differentiation roles. Apoptosis is activated by the intrinsic pathway after castration and by the extrinsic pathway after ERß agonist treatment. This differential activation of apoptotic pathways is important since a major problem in the treatment of prostate cancer is the recurrence of tumors after androgen withdrawal. However, a comprehensive study about the pattern of apoptosis in the aging prostate is lacking, a knowledge gap that we aimed to address herein. METHODS: Cellular age-related proliferative and apoptotic profiles of prostate tissue obtained from aging Wistar rats were evaluated. Cell death (caspase-3, -8, -9, TNFα) was assessed by immunohistochemistry, immunofluorescence, and TUNEL. Cell proliferation (MCM7) and cell survival factors (ERK1/2, p-ERK1/2, p-Akt, and NF-κB) were determined by immunohistochemistry. RESULTS: As the rats aged, the number of proliferating cells gradually reduced in the normal epithelium of all prostate lobes, while increasing in focal areas of intraepithelial proliferation. Interestingly, in areas of intraepithelial proliferation, we observed a reduction in the number of cells positive for caspase-3, -8, and -9. Regardless the animal's age, few prostate epithelial cells were positive for caspase-3, caspase-9, and TUNEL. In contrast, a progressive increase was seen in the positivity for caspase-8, especially in the atrophic epithelium of ventral prostate, which coincided with a reduction in TNFα immunoreaction. However, morphology of most caspase-8 positive cells suggests that they were not apoptotic. We also found reduced ERß expression in the same areas. Possibly, low levels of the pro-apoptotic inductors TNFα and ERß direct caspase-8 activity to an alternative pro-survival role in the atrophic epithelium. This hypothesis is supported by the increased expression of the key survival factors (ERK1/2, p-ERK1/2, p-Akt, and NF-κB) in these areas. CONCLUSIONS: Our findings reveal that, as the animals age, there is an increase of proliferation in restricted areas of the prostate epithelium, and a concomitant reduction of the apoptosis rate with an increase in cell survival induced by caspase-8, indicating a focused and spontaneous disruption of tissue homeostasis.

ORC1/CDC6 and MCM7 distinct associate with chromatin through Trypanosoma cruzi life cycle.

Trypanosoma cruzi alternates between replicative and non-replicative stages. We analyzed the expression of components of the pre-replication machinery TcORC1/CDC6 and TcMCM7 and their interaction with DNA in all T. cruzi stages. TcORC1/CDC6 remains in the nuclear space during all stages of the life cycle and interacts with DNA in the replicative stages; however, it does not bind to DNA in the non-replicative forms. Moreover, TcMCM7 is not present in the non-replicative stages. These data suggest that the lacking of DNA replication during the T. cruzi life cycle may be a consequence of the blocking of TcORC1/CDC6-DNA interaction and of the down regulation of the TcMCM7 expression.

Effects of hypo- and hyperthyroidism on proliferation, angiogenesis, apoptosis and expression of COX-2 in the corpus luteum of female rats.

Although thyroid dysfunction occurs frequently in humans and some animal species, the mechanisms by which hypo- and hyperthyroidism affect the corpus luteum have not been thoroughly elucidated. This study evaluated the levels of proliferative activity, angiogenesis, apoptosis and expression of cyclooxygenase-2 in the corpus luteum of female rats with thyroid dysfunction. These processes may be important in understanding the reproductive changes caused by thyroid dysfunction. A total of 18 adult female rats were divided into three groups (control, hypothyroid and hyperthyroid) with six animals per group. Three months after treatment to induce thyroid dysfunction, the rats were euthanized in the dioestrus phase. The ovaries were collected and immunohistochemically analysed for expression of the cell proliferation marker CDC-47, vascular endothelial growth factor (VEGF), VEGF receptor Flk-1 and cyclooxygenase-2 (COX-2). Apoptosis was evaluated using the TUNEL assay. Hypothyroidism reduced the intensity and area of COX-2 expression in the corpus luteum (p < 0.05), while hyperthyroidism did not alter COX-2 expression in the dioestrus phase. Hypothyroidism significantly reduced the expression of CDC-47 in endothelial cells and pericytes in the corpus luteum, whereas hyperthyroidism did not induce a detectable change in CDC-47 expression (p > 0.05). Hypothyroidism reduced the level of apoptosis in luteal cells (p < 0.05) and increased VEGF expression in the corpus luteum. In contrast, hyperthyroidism increased the level of apoptosis in the corpus luteum (p < 0.05). In conclusion, thyroid dysfunction differentially affects the levels of proliferative activity, angiogenesis and apoptosis and COX-2 expression in the corpus luteum of female rats.

Fetal growth restriction in hypothyroidism is associated with changes in proliferative activity, apoptosis and vascularisation of the placenta.

The objective of this study was to evaluate fetal weight, histomorphometric changes and proliferative activity, apoptosis and angiogenesis of the placenta in rats with hypothyroidism. Thirty-six adult female rats were divided into two groups with 18 animals each: control and hypothyroidism. Hypothyroidism was induced by daily administration of propylthiouracil (1 mg/animal). The administration began five days before becoming pregnant and the animals were sacrificed at 14 or 19 days of gestation. The control group received a placebo. The number and weight of fetuses and the rate of fetal death was determined, as well as the morphometric characteristics, the immunohistochemical expression of cell division control protein 47 (CDC)-47 and vascular endothelial growth factor (VEGF) and the number of apoptotic cells in the placental disk. The data were analysed by Mann-Whitney U test. Hypothyroidism reduced the weight of fetuses and of the uterus and placenta (P<0.05), altered the thickness of the placental labyrinth and spongiotrophoblast (P<0.05), increased the population of glycogen cells in the spongiotrophoblast (P<0.05), interfered with the vascular development of the placental labyrinth and decreased VEGF expression (P<0.05), reduced the expression of CDC-47 and cellularity and increased the apoptotic rate in the placental disk (P<0.05). We conclude that hypothyroidism affects fetal weight by altering the proliferative activity, apoptosis and vascularisation of the placenta.

[Apoptosis, proliferation and spleen histomorphometry of adult female rats with thyroid and ovarian hypofunction]. / Apoptose, proliferação e histomorfometria do baço de ratas adultas com hipofunção tireoidiana e ovariana.

Apoptosis, proliferation and histomorphometry of spleen were investigated in ovariectomized and non-ovariectomized adult Wistar rats maintained in hypothyroidism induced by daily administration of propylthiouracil (PTU) during 120 days. Two groups ovariectomized euthyroid and non-ovariectomized euthyroid were used as controls. Plasma was collected for free T4 dosage and the spleen for histomorphometry analysis, apoptosis index and the immunohistochemistry expression of caspase 3 and CDC47. Values of free T4 were lower in rats treated with PTU (p<0.05). In the hypothyroid groups there was some decrease in the spleen weight as well as the number and size of lymphoid follicles and there was some increase in the apoptotic index and the caspase 3 expression (p<0.05). However, the increase in the apoptosis index and the expression of caspase 3 in ovariectomized hypothyroid rats spleen was less accentuated than non-ovariectomized hypothyroid ones (p<0.05). The ovariectomized euthyroid group presented white pulp hyperplasia in comparison to the non-ovariectomized euthyroid group. There was no difference in the CDC47 expression between groups. It was concluded that the thyroid and ovarian hypofunction have distinct effects on the spleen and that in the hypothyroidism-hypogonadism association, the increase in the apoptosis index and in the expression of splenic caspase 3 is not as much as in isolated hypothyroidism.

Histomorphometry and expression of CDC-47 and caspase-3 in mammary glands of pregnant female rats with artificial hyperthyroidism.

The purpose of this study was to evaluate the effect of hyperthyroidism on mammary gland development and expression of two protein markers, CDC-47 for proliferation and caspase-3 for apoptosis in pregnant female rats. Thirty-six adult female Wistar rats were used in two groups: hyperthyroid and control. Rats were mated 60 days after the onset of thyroxine administration. Six animals/group were sacrificed on gestation days 7, 14, and 19. Artificial hyperthyroidism was induced by daily administration of thyroxine in the drinking water until the end of gestation. At the end of each period, rats were sacrificed, and their inguinal mammary glands were collected and processed for morphometric analysis. The percentages of epithelium, stroma, adipose tissue, and lacteal secretion were determined. Immunohistochemical analysis was also carried out using anti-CDC-47 and anti-caspase-3 antibodies to study proliferation and apoptosis, respectively. On the 19th day of gestation, thyroxine treatment significantly increased the percentage of mammary epithelium. Hyperthyroidism, however, did not change CDC-47 expression. The hyperthyroid group presented early lactogenesis and significantly larger lacteal secretion on the 19th day of gestation. There was no significant difference in caspase-3 expression between groups in any period. We may conclude that hyperthyroidism accelerates mammary gland development and increases lacteal secretion during gestation without increasing the proliferation rate and the expression of caspase-3.

Histomorphometry and expression of Cdc47 and caspase-3 in hyperthyroid rat uteri and placentas during gestation and postpartum associated with fetal development.

In two different experiments, the effects of hyperthyroidism on the histomorphometry and expression of Cdc47 and caspase-3 were evaluated in the uteri and placentas during gestation and postpartum. Fetal development was also evaluated during gestation. In the first experiment, 36 adult female Wistar rats were divided into two groups of 18 animals each: (1) hyperthyroid; and (2) euthyroid (control). Female rats were mated and killed at 7, 14 and 19 days of gestation. Uteri and placentas were weighed and subjected to histomorphometric and immunohistochemical evaluation to determine the expression of Cdc47 and caspase-3. Ovaries were also evaluated for weight and subjected to morphometric analysis. Fetuses were quantified and weighed individually. In the second experiment, 12 adult female Wistar rats were divided into two groups of six animals each: (1) hyperthyroid; and (2) euthyroid (control). Female rats were mated and killed 2 days postpartum. Uteri were evaluated in the same way as for the first experiment. Hyperthyroidism increased ovulation and conception rates without disturbing the size and viability of the fetuses. In the pregnant uteri, hyperthyroidism did not change the thickness of the layers or the expression of Cdc47 and caspase-3. However, in the placentas, hyperthyroidism increased the medium diameter of trophoblast cells, as well as the thickness and the expression of Cdc47 of spongiotrophoblast cells, at 14 days of gestation. During uterine involution, hyperthyroidism significantly increased the expression of Cdc47 and reduced the expression of caspase-3 in the uterine layers. In conclusion, hyperthyroidism increased the conception rate because of an ovulation gain, induced significant placental changes during pregnancy and, in the uterus, increased Cdc47 expression and decreased caspase-3 expression after parturition.