Hyperthyroidism keeps immunoglobulin levels but reduces milk fat and CD11b/c+ cells on early lactation.

Thyroid hormones influence mammary gland differentiation and lactation by binding to thyroid hormone receptors. Hyperthyroidism disrupts pregnancy and lactation, affecting offspring growth and milk production. Despite maternal milk is a vital source of bioactive compounds and nutrients for newborns, it is unclear whether hyperthyroidism alters its composition, mainly immune factors. Therefore, our work aimed to evaluate the influence of hyperthyroidism on milk quality and immunological parameters during early lactation. Twelve-week-old female Wistar rats received daily injections of 0,25 mg/kg T4 (HyperT, n=20) or vehicle (control, n=19) starting 8 days before mating and continuing throughout pregnancy. Rats were euthanized on day 2 of lactation for analyzing the impact of hyperthyroidism on mammary gland, serum and milk samples. HyperT pups exhibited reduced weight, length and head circumference with altered serum hormones, glucose and albumin levels. HyperT mammary gland analysis revealed structural changes, including decreased alveolar area, adipose tissue, increased connective tissue and reduced epithelial elongation, accompanied by decreased TRß1 RNA expression. HyperT milk displayed lower caloric value and fat concentration. HyperT animals exhibited altered milk immune cell counts, displaying increased numbers of CD45+ and CD3+ cells and decreased CD11b/c+ cells without changes on milk and serum IgA, IgG and IgG2a levels. In summary, we have demonstrated that hyperthyroidism affects mammary gland morphology, disrupts pup development and alters biochemical and immunological parameters. Our findings highlight the impact of maternal hyperthyroidism on offspring early development and milk immune composition, underscoring the importance of thyroid function in maternal and neonatal immune health.

Placental leukocyte infiltration accompanies gestational changes induced by hyperthyroidism.

In brief: The endocrine and immunological disruption induced by hyperthyroidism could alter gestation, placenta, and fetal development. This study suggests an immunological role of thyroid hormones in gestation. Abstract: Thyroid dysfunctions lead to metabolic, angiogenic, and developmental alterations at the maternal-fetal interface that cause reproductive complications. Thyroid hormones (THs) act through their nuclear receptors that interact with other steroid hormone receptors. Currently, immunological regulation by thyroid status has been characterized to a far less extent. It is well known that THs exert regulatory function on immune cells and modulate cytokine expression, but how hyperthyroidism (hyper) modulates placental immunological aspects leading to placental alterations is unknown. This work aims to throw light on how hyper modulates immunological and morphological placental aspects. Control and hyper (induced by a daily s.c. injection of T4 0.25 mg/kg) Wistar rats were mated 8 days after starting T4 treatment and euthanized on days 19 (G19) and 20 (G20) of pregnancy. We removed the placenta to perform qPCR, flow cytometry, immunohistochemistry, Western blot and histological analysis, and amniotic fluid and serum to evaluate hormone levels. We observed that hyper increases the fetal number, fetal weight, and placental weight on G19. Moreover, hyper induced an endocrine imbalance with higher serum corticosterone and changed placental morphology, specifically the basal zone and decidua. These changes were accompanied by an increased mRNA expression of glucocorticoid receptor and monocyte chemoattractant protein-1, an increased mRNA and protein expression of prolactin receptor, and an increase in CD45+ infiltration. Finally, by in vitro assays, we evidenced that TH induced immune cell activation. In summary, we demonstrated that hyper modulates immunological and morphological placental aspects and induces fetal phenotypic changes, which could be related to preterm labor observed in hyper.

Desmoglein-4 Deficiency Exacerbates Psoriasiform Dermatitis in Rats While Psoriasis Patients Displayed a Decreased Gene Expression of DSG4.

Desmogleins are involved in cell adhesion conferring structural skin integrity. However, their role in inflammation has been barely studied, and whether desmoglein-4 modulates psoriasis lesions is completely unknown. In this study, we assessed the impact of desmoglein-4 deficiency on the severity of imiquimod (IMQ)-induced skin inflammation and psoriasiform lesions. To this end, desmoglein-4-/- Oncins France Colony A (OFA) with Sprague-Dawley (SD) genetic background were used. Additionally, human RNA-Seq datasets from psoriasis (PSO), atopic dermatitis (AD), and a healthy cohort were analyzed to obtain a desmosome gene expression overview. OFA rats displayed an intense skin inflammation while SD showed only mild inflammatory changes after IMQ treatment. We found that IMQ treatment increased CD3+ T cells in skin from both OFA and SD, being higher in desmoglein-4-deficient rats. In-depth transcriptomic analysis determined that PSO displayed twofold less DSG4 expression than healthy samples while both, PSO and AD showed more than three-fold change expression of DSG3 and DSC2 genes. Although underlying mechanisms are still unknown, these results suggest that the lack of desmoglein-4 may contribute to immune-mediated skin disease progression, promoting leukocyte recruitment to skin. Although further research is needed, targeting desmoglein-4 could have a potential impact on designing new biomarkers for skin diseases.

Thyroid Hormone Controls Breast Cancer Cell Movement via Integrin αV/ß3/SRC/FAK/PI3-Kinases.

Thyroid hormones (TH) play a fundamental role in diverse processes, including cellular movement. Cell migration requires the integration of events that induce changes in cell structure towards the direction of migration. These actions are driven by actin remodeling and stabilized by the development of adhesion sites to extracellular matrix via transmembrane receptors linked to the actin cytoskeleton. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that promotes cell migration and invasion through the control of focal adhesion turnover. In this work, we demonstrate that the thyroid hormone triiodothyronine (T3) regulates actin remodeling and cell movement in breast cancer T-47D cells through the recruitment of FAK. T3 controls FAK phosphorylation and translocation at sites where focal adhesion complexes are assembled. This process is triggered via rapid signaling to integrin αV/ß3, Src, phosphatidylinositol 3-OH kinase (PI3K), and FAK. In addition, we established a cellular model with different concentration of T3 levels: normal, absence, and excess in T-47D breast cancer cells. We found that the expression of Src, FAK, and PI3K remained at normal levels in the excess of T3 model, while it was significantly reduced in the absence model. In conclusion, these results suggest a novel role for T3 as an important modulator of cell migration, providing a starting point for the development of new therapeutic strategies for breast cancer treatment.

Paxillin, a novel controller in the signaling of estrogen to FAK/N-WASP/Arp2/3 complex in breast cancer cells.

Breast cancer is the major cause of cancer-related death in women. Its treatment is particularly difficult when metastasis occurs. The ability of cancer cells to move and invade the surrounding environment is the basis of local and distant metastasis. Cancer cells are able to remodel the actin cytoskeleton, which requires the recruitment of numerous structural and regulatory proteins that modulate actin filaments dynamics, including Paxillin or the Neural Wiskott-Aldrich Syndrome Protein (N-WASP). We show that 17-ß estradiol (E2) induces phosphorylation of Paxillin and its translocation toward membrane sites where focal adhesion complexes are assembled. This cascade is triggered by a Gαi1/Gß protein-dependent signaling of estrogen receptor α (ERα) to c-Src, focal adhesion kinase (FAK) and Paxillin. Within this complex, activated Paxillin recruits the small GTPase Cdc42, which triggers N-WASP phosphorylation. This results in the redistribution of Arp2/3 complexes at sites where membrane structures related to cell movement are formed. Recruitment of Paxillin, Cdc42 and N-WASP is necessary for cell adhesion, migration and invasion induced by E2 in breast cancer cells. In parallel, we investigated whether Raloxifene (RAL), a selective estrogen receptor modulator (SERMs), could inhibit or revert the effects of E2 in breast cancer cell movement. We found that, in the presence of E2, RAL acts as an ER antagonist and displays an inhibitory effect on estrogen-promoted cell adhesion and migration via FAK/Paxillin/N-WASP. Our findings identify an original mechanism through which estrogen regulates breast cancer cell motility and invasion via Paxillin. These results may have clinical relevance for the development of new therapeutic strategies for cancer treatment.