Dataset Information

Bmp7 functions via a polarity mechanism to promote cloacal septation.

ABSTRACT: BACKGROUND:During normal development in human and other placental mammals, the embryonic cloacal cavity separates along the axial longitudinal plane to give rise to the urethral system, ventrally, and the rectum, dorsally. Defects in cloacal development are very common and present clinically as a rectourethral fistula in about 1 in 5,000 live human births. Yet, the cellular mechanisms of cloacal septation remain poorly understood. METHODOLOGY/PRINCIPAL FINDINGS:We previously detected Bone morphogenetic protein 7 (Bmp7) expression in the urorectal mesenchyme (URM), and have shown that loss of Bmp7 function results in the arrest of cloacal septation. Here, we present evidence that cloacal partitioning is driven by Bmp7 signaling in the cloacal endoderm. We performed TUNEL and immunofluorescent analysis on cloacal sections from Bmp7 null and control littermate embryos. We found that loss of Bmp7 results in a dramatic decrease in the endoderm survival and a delay in differentiation. We used immunological methods to show that Bmp7 functions by activating the c-Jun N-terminal kinase (JNK) pathway. We carried out confocal and 3D imaging analysis of mitotic chromosome bundles to show that during normal septation cells in the cloacal endoderm divide predominantly in the apical-basal direction. Loss of Bmp7/JNK signaling results in randomization of mitotic angles in the cloacal endoderm. We also conducted immunohistochemical analysis of human fetal sections to show that BMP/phospho-SMAD and JNK pathways function in the human cloacal region similar as in the mouse. CONCLUSION/SIGNIFICANCE:Our results strongly indicate that Bmp7/JNK signaling regulates remodeling of the cloacal endoderm resulting in a topological separation of the urinary and digestive systems. Our study points to the importance of Bmp and JNK signaling in cloacal development and rectourethral malformations.

SUBMITTER: Xu K

PROVIDER: S-EPMC3258230 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Bmp7 functions via a polarity mechanism to promote cloacal septation.

Xu Kun K Wu Xinyu X Shapiro Ellen E Huang Honging H Zhang Lixia L Hickling Duane D Deng Yan Y Lee Peng P Li Juan J Lepor Herbert H Grishina Irina I

PloS one 20120113 1

<h4>Background</h4>During normal development in human and other placental mammals, the embryonic cloacal cavity separates along the axial longitudinal plane to give rise to the urethral system, ventrally, and the rectum, dorsally. Defects in cloacal development are very common and present clinically as a rectourethral fistula in about 1 in 5,000 live human births. Yet, the cellular mechanisms of cloacal septation remain poorly understood.<h4>Methodology/principal findings</h4>We previously detec ...[more]

PMID: 22253716

Similar Datasets

Project description:Bone morphogenetic proteins (BMPs) are the structurally similar and highly conserved type of functional proteins that play an important role in hair follicle growth and development. BMP7 was a differentially expressed gene in different patterns of Hu sheep lambskin identified using Agilent microarray. Since hair follicle is the basis of pattern formation of lambskin, and its growth and development is governed by dermal papilla cells (DPCs), to clarify the role of BMP7 and hair follicle, our study was designed to investigate the regulation between BMP7 and DPCs. Firstly, the CDS region of BMP7 was cloned by 3'Race and PCR in Hu sheep and performed serious of bioinformatic analysis. Then, the effects of BMP7 on DPCs were analyzed after overexpression and interference of BMP7 in dermal papilla cells by CCK8, EdU, and PI assay. Additionally, qPCR was also conducted to clarify the relationship between BMP7 and the TGF-β/Smad signaling pathway. A total of 1296 bp of the BMP7 CDS region sequence was sucessfully cloned in Hu sheep, encoding a signal peptide of 431 amino acids, molecular weight was 49,316.9 Da and the isoelectric point (Pi) was 7.75. Nucleotide sequencing analysis of BMP7 revealed that Hu sheep had high homology with Bos taurus, Homo sapiens, and Canis lupus familiaris. Structure domain prediction showed that TGF-β superfamily domain exist between 330th-431th amino acid, BMP7 protein is a secreted protein. In BMP7 up-regulated DPCs, DPCs proliferation rate and cell cycle were significantly higher than that of NC group (p < 0.05). Meanwhile, the expression level of Smad3, Smad4, Samd6, and TGF-β1 in TGF-β/Smad signaling pathway were significantly lower than that in NC group (p < 0.05). In BMP7 down-regulated DPCs, it presented the opposite result. In conclusion, our study showed that BMP7 had a positive effect on DPCs by accelerating the proliferation and cell cycle of DPCs, and hypothesized that regulate hair follicles growth and development via TGF-β/Smad signaling pathway. These findings may provide a synergistic target for the subsequent research of hair follicle growth and development.

Project description:Prions are self-perpetuating conformational variants of particular proteins. In yeast, prions cause heritable phenotypic traits. Most known yeast prions contain a glutamine (Q)/asparagine (N)-rich region in their prion domains. [PSI+], the prion form of Sup35, appears de novo at dramatically enhanced rates following transient overproduction of Sup35 in the presence of [PIN+], the prion form of Rnq1. Here, we establish the temporal de novo appearance of Sup35 aggregates during such overexpression in relation to other cellular proteins. Fluorescently-labeled Sup35 initially forms one or a few dots when overexpressed in [PIN+] cells. One of the dots is perivacuolar, colocalizes with the aggregated Rnq1 dot and grows into peripheral rings/lines, some of which also colocalize with Rnq1. Sup35 dots that are not near the vacuole do not always colocalize with Rnq1 and disappear by the time rings start to grow. Bimolecular fluorescence complementation failed to detect any interaction between Sup35-VN and Rnq1-VC in [PSI+][PIN+] cells. In contrast, all Sup35 aggregates, whether newly induced or in established [PSI+], completely colocalize with the molecular chaperones Hsp104, Sis1, Ssa1 and eukaryotic release factor Sup45. In the absence of [PIN+], overexpressed aggregating proteins such as the Q/N-rich Pin4C or the non-Q/N-rich Mod5 can also promote the de novo appearance of [PSI+]. Similar to Rnq1, overexpressed Pin4C transiently colocalizes with newly appearing Sup35 aggregates. However, no interaction was detected between Mod5 and Sup35 during [PSI+] induction in the absence of [PIN+]. While the colocalization of Sup35 and aggregates of Rnq1 or Pin4C are consistent with the model that the heterologous aggregates cross-seed the de novo appearance of [PSI+], the lack of interaction between Mod5 and Sup35 leaves open the possibility of other mechanisms. We also show that Hsp104 is required in the de novo appearance of [PSI+] aggregates in a [PIN+]-independent pathway.

Dataset Information

Bmp7 functions via a polarity mechanism to promote cloacal septation.

Publications

Bmp7 functions via a polarity mechanism to promote cloacal septation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets