Molecular and Cellular Endocrinology最新文献

Although maternal obesity influences placental and fetal development, the underlying molecular mechanisms have yet to be determined. Oxidative and inflammatory status at the fetal-placental unit appear to be involved in the early fetal metabolic programming. The objective of the present study is to reveal a potential role of sphingolipids in stablishing an oxidative and inflammatory status in the maternal-placental-fetal unit, as function of fetal sex. Term placenta and maternal and fetal plasma were collected from lean (BMI 18-25 kg/m²) and obese women (BMI 30-40 kg/m²) without gestational diabetes aged from 20 to 40 having undergone a cesarean section. Firstly, key markers of oxidative stress and inflammation were studied with immunoblotting and biochemical assays. Secondly, the maternal-placental-fetal unit's sphingolipid profile was determined by mass spectrometry. Lastly, the placental samples' transcriptome was analyzed by RNA sequencing. Obese mothers showed lower plasma levels of ceramide Cer 20:0 (p = 0.02). Surprisingly, placental ceramide content was not influenced by maternal obesity. Nevertheless, male placentas from obese women showed a higher sphingomyelin content and hypo-inflammation as showed by RNAseq. Both males and female placentas from obese women showed higher levels of oxidative stress as showed by the oxidative stress markers (protein carbonylation and lipid peroxidation). However, RNAseq revealed an upregulation of oxidative stress mechanisms only in female placentas. Whatever the newborn's sex, maternal obesity was associated with higher fetal plasma oxidative stress. In conclusion, our results revealed sex-specific features in the placental transcriptome, highlighted placental metabolic adaptations, and provided insights into the underlying molecular mechanisms of fetal programming.

Breast cancer is the most prevalent neoplasia in women worldwide. Triple negative breast cancer (TNBC) is a subtype characterized by the absence of estrogen receptor, progesterone receptor and HER2 expression. Bisphenol A (BPA) is a chemical used in the synthesis of polycarbonate plastics and epoxy resins and its intake is related with breast cancer progression. Extracellular vesicles (EVs) are vesicles released by cells that mediate intercellular communication. However, the role of BPA in the release of EVs mediating cancer progression in TNBC remains to be studied. We hypothesize that EVs from BPA-stimulated TNBC cells promote metastasis-related processes, tumor growth and enhanced metastasis in a breast cancer mouse model. This study aims to evaluate the functional role of EVs from BPA-stimulated TNBC cells in metastasis-related processes and breast cancer progression using "in vitro" 4T1 cells models and an "in vivo" breast cancer mouse model. Findings demonstrate that exposition of TNBC 4T1 cells to EVs from TNBC MDA-MB-231 cells stimulated with 1 μM BPA for 24 h (BPA-EVs) significantly increases migration, invasion and MMP-9 secretion, compared to 4T1 cells exposed to EVs from non-stimulated MDA-MB-231 cells (Ctrl-EVs). Furthermore, Balb/cJ mice inoculated in mammary fat pad with 4T1 cells exposed to BPA-EVs show mammary tumors with more weight and volume, and more metastatic nodules in lung and liver than Balb/cJ mice inoculated with 4T1 cells exposed to Ctrl-EVs. In conclusion, BPA-EVs represent a significant mediator of TNBC progression, which defining the EVs as a novel element through which BPA promotes breast cancer progression.

High fat diet (HFD) induces glomerulopathy and proximal tubule injury. The precise pathophysiological mechanisms triggering obesity-related kidney impairment remain elusive, especially after dietary correction. Male C57BL6/J mice (n = 15) were divided in: control group (CTR) fed with standard chow; a group fed with HFD for 200 days (28-29 weeks); and a group fed with HFD for 60 days (8-9 weeks) and then with standard chow (HFDt)(∼21 weeks). Biometric data and whole-body metabolism were assessed. Expression of genes associated with mitochondrial dynamics, mitochondrial complexes and antioxidant defenses were analyzed. Kidney homogenates enriched in mitochondria were prepared and characterized by mass spectrometry-based proteomics. Kidney tissue of mice fed HFD exhibited reduced PGC-1α expression, an imbalance between fusion (increased MFN1 and decreased OPA1) and fission (decreased FIS1 and DRP1) processes. The activity of mitochondrial complex I (CI) was increased, while activity of complex II (CII) was decreased in the kidney after HFD and HFDt. Antioxidant defense Manganese Superoxide dismutase (MnSOD) was decreased in the kidney of HFD, while Glutathione reductase (GR) increased, with both activities being restored upon dietary reversion. Proteomic analysis showed alterations in proteins associated with glutathione and glycine metabolism, fatty acid oxidation (FAO), and peroxisomal function. HFD negatively impacted kidney glutathione related proteins (Gsta3 and Gsr); however dietary correction reverted this condition. Acsm3 protein was downregulated in kidney after HFD and upregulated after dietary correction. Some machinery is shared by mitochondria and peroxisomes, with their network being crucial particularly under stress conditions. A HFD impaired kidney FAO in peroxisomes, as evidenced by downregulation of Pecr after HFD and HFDt. Dietary correction after early-obesity mitigates the systemic metabolic dysfunction and can attenuate mitochondria dysfunction but is unable to completely restore mitochondria dynamics and bioenergetics. The results highlight the integrity of mitochondrial network as a main point for targeted therapeutic strategies aimed at preventing the progression of kidney disease.

Postnatal differentiation of gonadotrophs from Sox2-expressing stem cells is essential for maturation of the hypothalamic-pituitary-gonadal axis, puberty, and reproduction. Here, we examined the differentiation and maintenance of gonadotrophs in developing and adult mice. Gonadotrophs and Sox2-expressing cells were identified by immunostaining, and gonadotrophs were also visualized by specific expression of the fluorescent protein tdTomato during embryonic and postnatal differentiation. Sox2-expressing cells are localized in the anterior parenchyma, marginal zone, and posterior pituitary, regardless of mouse age. Gonadotrophs are localized in the anterior parenchyma separate from Sox2-expressing cells. During the juvenile and prepubertal periods, cells in transition from Sox2 expression to tdTomato expression, as well as numerous differentiated gonadotrophs, were also present in the marginal zone. The size and distribution of the newly differentiated gonadotrophs were consistent with their migration into the parenchyma and maturation into a secretory cell type. Specific knockout of PI4-kinase A in gonadotrophs slowed their postnatal differentiation in the marginal zone, causing a significant reduction in the size of the gonadotroph population. This was accompanied by a progressive loss of specific gene expression in the residual gonadotrophs, leading to an increase in the number of dedifferentiated cells expressing tdTomato. Thus, Sox2 expressing cells in the marginal zone serve as stem cells for postnatal gonadotrophs, and the differentiation and maintenance of these cells require phosphoinositides derived by PI4-kinase A.