NR2F2 regulates chondrogenesis of human mesenchymal stem cells in bioprinted cartilage.

Bioprinting as an advanced enabling technology has the capacity to construct tissues with respective anatomical structures. In order to maintain the precise printing resolution for anatomical tissue printing, cell seeding density in bioink is limited. Bone marrow derived mesenchymal stem cells (MSCs) are widely used for cartilage tissue engineering. However, the approach of ideal chondrogenic differentiation of MSCs without hypertrophy still remains elusive. Here, we reported NR2F2 plays a crucial role in MSC chondrogenesis in bioprinted cartilage. NR2F2 over-expressed MSCs showed significantly enhanced chondrogenesis and NR2F2 knockdown cells demonstrated the exactly opposite behavior. We evaluated the cells cultured in monolayer, 3D pellet, and bioprinted 3D scaffold. All observations were consistent among gene expression, biochemical analysis, histological assay, and biomechanical evaluation. The data also revealed possible involvement of NR2F2 in mechanism of MSC chondrogenic differentiation under hypoxic culture condition. Biotechnol. Bioeng. 2017;114: 208-216. © 2016 Wiley Periodicals, Inc.

High expression of COUP-TF II cooperated with negative Smad4 expression predicts poor prognosis in patients with colorectal cancer.

OBJECTIVE: In order to evaluate whether the role of chicken ovalbumin upstream promoter transcription factor II (COUP-TF II) could sever as a predictor to stratify risk of human colorectal cancer (CRC) patients, and to elucidate the preliminary molecular mechanisms of COUP-TF II involved in the development and advancement of CRC reflected by investigating the relationship of COUP-TF II with PTEN, Smad4. METHODS: 112 cases tissue microarray and immunohistochemical SP method were used to detect the expression of COUP-TF II, PTEN and Smad4 in CRC tissues and adjacent non-tumorous tissues. The clinical relevance and prognosis of COUP-TF II, PTEN, Smad4 in CRC patients were analyzed. Furthermore, Cox proportional hazards model was performed to indicate the independent prognostic factors for CRC patients using various clinicopathological parameters and COUP-TF II, PTEN and Smad4. RESULTS: COUP-TF II proteins were positively expressed in 65.2% of CRC tissues and 15.5% paired non-CRC tissues, respectively. The expression of COUP-TF II was significantly correlated with TNM stage and lymph node metastasis and a negative correlation with Smad4 expression. Patients bearing higher levels of COUP-TF II expression showed lower DFS and OS. Most importantly, Cox proportional hazards regression analyses showed COUP-TF II positive/Smad4 negative status (DFS, P=0.001; OS, P=0.005) were independent prognostic factors for CRC patients. CONCLUSION: Positive COUP-TF II expression levels has significant value in determining CRC stage and metastasis and cooperates with negative Smad4 expression contributing to assess prognosis in patients with colorectal cancer, suggesting Smad4 may be involved in the above regulation progress probably.

The expression profiles of nuclear receptors in the developing and adult kidney.

Nuclear receptors are transcriptional regulators that play important roles in embryonic development and organogenesis. To study the potential roles of nuclear receptors in kidney development, we examined the expression patterns of a subset of nuclear receptors in which specific antibodies are available for profiling using immunohistochemistry. As a prototype for our analysis, we investigated the expression patterns of chicken ovalbumin upstream promoter transcription factor (COUP-TF) -I and -II in more details during embryonic development and in the adult by immunohistochemistry. We showed that COUP-TFI is expressed in the stroma and mesenchymal cells at embryonic d 11.5 (E11.5) and expression persists throughout embryonic development. In the adult kidney, only mesangial cells show meaningful COUP-TFI expression. In contrast, COUP-TFII expression is detected as early as E9.5 and high expression is seen in the mesenchymal-derived epithelial cells but not in the ureteric buds through E12.5. At E13.5, COUP-TFII expression becomes regionalized with higher expression in the region that gives rise to the distal tubule. The proximal part of the S-shaped body that will become the glomerulus after endothelial cell migration shows COUP-TFII expression in podocyte precursor cells and epithelial cells of the Bowman's capsule. In the adult mouse kidney, COUP-TFII is detected in distal tubules, podocytes, and the epithelial cells of the Bowman's capsule. In addition to COUP-TFs, we also examined the expression profiles of eight other nuclear receptors (farnesoid X receptor, vitamin D receptor, hepatocyte nuclear factor 4alpha, retinoid X receptor alpha, mineralocorticoid receptor, steroidogenic factor 1, liver receptor homolog-1, and germ cell nuclear factor). Our results suggest that these nuclear receptors are likely to play important physiological roles in the kidney development.

Decreased CYP3A2 expression and activity in senescent male Wistar rats: is there a role for HNF4alpha?

The effect of ageing on CYP3A2, a male specific isoform, was examined in adult (9 months) and senescent (24 months) male rats. A significant decrease (65%) of CYP3A2-related activity (midazolam oxidation) was observed in all senescent rats. Half of these rats still express CYP3A2 suggesting that decreased activities in these rats are due to post-translational modifications. The other senescent male rats did not express CYP3A2 anymore, indicating an impairment of transcription. These transcriptional modifications are due to the previously shown continuous secretion of GH in senescent male rats. GH also regulates HNF4alpha, a hepatocyte nuclear factor, essential for the basal transcriptional activation of the CYP3A2 gene. In senescent rats, a drastic reduction (76%) of HNF4alpha protein content and a decrease in DNA binding activity were observed. When these parameters were assessed in male and female rats of the same age (3 months), a higher HNF4alpha DNA binding activity and a higher HNF4alpha protein content (38%) were observed in female rats. Our results show that in male senescent rats (1) the decrease of HNF4alpha is not consistent with the continuous secretion of GH, and (2) the suppression of CYP3A2 expression is not dependent to the HNF4alpha binding activity.

Cloning, expression and regulation of chicken ovalbumin upstream promoter transcription factors (COUP-TFII and EAR-2) in the rat anterior pituitary gland.

Chicken ovalbumin upstream promoter transcription factors (COUP-TF)-II (NR2F2) and EAR-2 (NR2F6) are structurally related orphan members of the nuclear receptors superfamily. There are growing evidences that these factors play important roles during processes of differentiation and proliferation of several tissues. To better understand their role in the differentiated adult rat pituitary gland, we cloned COUP-TFII and EAR-2 cDNAs from an anterior pituitary cDNA library. Subsequently, we raised and characterized specific antibodies to the N-terminal domain of both nuclear receptors. We next examined their cellular and subcellular distribution in the pituitary gland and determined their regulation during pregnancy. COUP-TFII and EAR-2 pituitary genes display, respectively, 90 and 100% homologies with their human and mouse homologues. Cellular expression of both nuclear receptors was mainly detected in the lactotropes of male and female rats, with a prominent distribution in the nuclear compartment for EAR-2, and interestingly both proteins were significantly upregulated in pituitaries of pregnant vs. cycling female rats. Thus, our results have characterized cloning of rat pituitary COUP-TFII and EAR-2 genes, demonstrated that they are both specifically expressed in lactotropes, and strongly suggested that they may play an important role in modulating prolactin (PRL) gene expression during pregnancy.