Environmental Health and Toxicology: Immunomodulation Promoted by Endocrine-Disrupting Chemical Tributyltin.

Tributyltin (TBT) is an environmental contaminant present on all continents, including Antarctica, with a potent biocidal action. Its use began to be intensified during the 1960s. It was effectively banned in 2003 but remains in the environment to this day due to several factors that increase its half-life and its misuse despite the bans.

Ouabain Effects on Human Anaplastic Thyroid Carcinoma 8505C Cells.

Anaplastic thyroid carcinoma (ATC) is a rare, but aggressive, carcinoma derived from follicular cells. While conventional treatments may improve patients' survival, the lethality remains high. Therefore, there is an urgent need for more effective ATC treatments.

In vitro antitumoral effects of the steroid ouabain on human thyroid papillary carcinoma cell lines.

Ouabain is a steroid described as a compound extracted from plants that is capable of binding to Na , K -ATPase, inhibiting ion transport and triggering cell signaling pathways. Due to its positive ionotropic effect, ouabain was used for more than 200 years for the treatment of cardiac dysfunctions. Numerous antitumor effects of ouabain have been described so far; however, its role on thyroid cancer is still poorly understood.

Glucocorticoid susceptibility and in vivo ABCB1 activity differ in murine B cell subsets.

Glucocorticoids are produced and released by the adrenal gland and become elevated in response to stress. Although glucocorticoids are well known for their immunosuppressive effects, less is known about their effects on B cells. ABCB1 is an efflux pump expressed in both cancer and normal cells, modulating the gradient of various metabolites, including hydrocortisone.

Enlarged colitogenic T cell population paradoxically supports colitis prevention through the B-lymphocyte-dependent peripheral generation of CD4(+)Foxp3(+) Treg cells.

Intestinal inflammation can be induced by the reconstitution of T/B cell-deficient mice with low numbers of CD4(+) T lymphocytes depleted of CD25(+)Foxp3(+) regulatory T cells (Treg). Using RAG-knockout mice as recipients of either splenocytes exclusively depleted of CD25(+) cells or FACS-purified CD4(+)CD25(-)Foxp3(-) T cells, we found that the augmentation of potentially colitogenic naïve T cell numbers in the inoculum was unexpectedly beneficial for the suppression of colon disease and maintenance of immune homeostasis. Protection against T cell-mediated colitis correlated with a significant increment in the frequency of peripherally-induced CD4(+)CD25(+)Foxp3(+) T (pTreg) cells, especially in the mesenteric lymph nodes, an effect that required the presence of B cells and CD4(+)CD25(-)Foxp3(+) cells in physiological proportions.

Dynamics of murine B lymphocytes is modulated by in vivo treatment with steroid ouabain.

Ouabain (OUA) is a steroid hormone capable of inhibiting the protein Na+K+ATPase present in the plasma membrane of cells. Ouabain was initially extracted from the roots of African trees such as Acocanthera ouabaio and Strophantus gratus seeds and later described as an endogenous component found in higher mammals. The adrenal gland is the main site of synthesis of ouabain and it is released in stressful situations, conditions similar to those where there is secretion of corticosteroids.

Modulation of mature B cells in mice following treatment with ouabain.

Ouabain (OUA) is an endogenous hormone released by the adrenal gland under stress situations. Steroid hormones and glucocorticoids have been characterized as selective inhibitors of lymphopoiesis. The present report shows in vivo modulation of mature B cells in bone marrow, spleen and peripheral blood by ouabain.

Inhibition of B cell development by kalanchosine dimalate.

Kalanchoe brasiliensis (Kb) is a medicinal plant from the Crassulaceae family, used in folk medicine to treat inflammatory and infectious diseases. Here we show that short-term treatment of mice with a highly purified compound named kalanchosine dimalate (KMC), obtained from Kb, led to a strong and selective inhibition of B cell development in the bone marrow, without affecting the myeloid lineage development. Numbers of mature B lymphocytes in bone marrow or peripheral lymphoid organs were preserved in KMC treated mice.

Selective blockade of lymphopoiesis induced by kalanchosine dimalate: inhibition of IL-7-dependent proliferation.

Lymphopoiesis and myelopoiesis continuously generate mature cells from hematopoietic cell progenitors during the lifetime of the organism. The identification of new endogenous or exogenous substances that can act specifically on the differentiation of distinct cell lineages is of relevance and has potential therapeutical use. Kalanchoe brasiliensis (Kb) is a medicinal plant from the Crassulaceae family, used in folk medicine to treat inflammatory and infectious diseases.