Involvement of BTBD1 in mesenchymal differentiation

MiR-200b-5p inhibits tumor progression in salivary adenoid cystic carcinoma via targeting BTBD1

Salivary adenoid cystic carcinoma (SACC) is a rare malignant tumor of the salivary gland. Studies have suggested that miRNA may play a crucial role in the invasion and metastasis of SACC. This study aimed to investigate the role of miR-200b-5p in SACC progression. Reverse transcription-quantitative PCR and western blot assay were used to detect the expression levels of miR-200b-5p and BTBD1. The biological functions of miR-200b-5p were evaluated via wound-healing assays, transwell assays, and xenograft nude mice model. The interaction between miR-200b-5p and BTBD1 was assessed using luciferase assay. Results showed that miR-200b-5p was downregulated in the SACC tissues while BTBD1 was upregulated. miR-200b-5p overexpression suppressed SACC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Bioinformatics prediction and luciferase reporter assay revealed that miR-200b-5p could directly bind to BTBD1. Besides, miR-200b-5p overexpression could rescue the tumor-promoting effect of BTBD1. miR-200b-5p inhibited tumor progression by modulating EMT-related proteins, targeting BTBD1 and inhibiting PI3K/AKT signaling pathway. Overall, our findings indicate that miR-200b-5p can suppress SACC proliferation, migration, invasion, and EMT by regulating BTBD1 and PI3K/AKT axis, providing a promising therapeutic target for SACC treatment.

Establishment and Verification of a Gene Signature for Diagnosing Type 2 Diabetics by WGCNA, LASSO Analysis, and In Vitro Experiments

Objective

The incidence and prevalence of type 2 diabetes are increasing with age. Nevertheless, there is lack of sensitive diagnostic tools and effective therapeutic regimens. We aimed to establish and verify a practical and valid diagnostic tool for this disease.

Methods

WGCNA was presented on the expression profiling of type 2 diabetic and normal islets in combined GSE25724 and GSE38642 datasets. By LASSO Cox regression analyses, a gene signature was constructed based on the genes in diabetes-related modules. ROC curves were plotted for assessing the diagnostic efficacy. Correlations between the genes and immune cell infiltration and pathways were analyzed. BST2 and BTBD1 expression was verified in glucotoxicity-induced and normal islet β cells. The influence of BST2 on β cell dysfunction was investigated under si-BST2 transfection.

Results

Totally, 14 coexpression modules were constructed, and red and cyan modules displayed the correlations to diabetes. The LASSO gene signature (BST2, BTBD1, IFIT1, IFIT3, and RTP4) was developed. The AUCs in the combined datasets and GSE20966 dataset were separately 0.914 and 0.910, confirming the excellent performance in diagnosing type 2 diabetes. Each gene in the model was distinctly correlated to immune cell infiltration and key signaling pathways (TGF-β and P53, etc.). The abnormal expression of BST2 and BTBD1 was confirmed in glucotoxicity-induced β cells. BST2 knockdown ameliorated β cell dysfunction and altered the activation of TGF-β and P53 pathways.

Conclusion

Our findings propose a gene signature with high efficacy to diagnose type 2 diabetes, which could assist and improve early diagnosis and therapy.

The Role of Cullin-RING Ligases in Striated Muscle Development, Function, and Disease

The well-orchestrated turnover of proteins in cross-striated muscles is one of the fundamental processes required for muscle cell function and survival. Dysfunction of the intricate protein degradation machinery is often associated with development of cardiac and skeletal muscle myopathies. Most muscle proteins are degraded by the ubiquitin-proteasome system (UPS). The UPS involves a number of enzymes, including E3-ligases, which tightly control which protein substrates are marked for degradation by the proteasome. Recent data reveal that E3-ligases of the cullin family play more diverse and crucial roles in cross striated muscles than previously anticipated. This review highlights some of the findings on the multifaceted functions of cullin-RING E3-ligases, their substrate adapters, muscle protein substrates, and regulatory proteins, such as the Cop9 signalosome, for the development of cross striated muscles, and their roles in the etiology of myopathies.

Identification of dosage-sensitive genes in fetuses referred with severe isolated congenital diaphragmatic hernia

OBJECTIVE

Congenital diaphragmatic hernia (CDH) is a fetal abnormality affecting diaphragm and lung development with a high mortality rate despite advances in fetal and neonatal therapy. CDH may occur either as an isolated defect or in syndromic form for which the prognosis is worse. Although conventional karyotyping and, more recently, chromosomal microarrays support a substantial role for genetic factors, causal genes responsible for isolated CDH remain elusive. We propose that chromosomal microarray analysis will identify copy number variations (CNVs) associated with isolated CDH.

METHODS

We perform a prospective genome-wide screen for CNVs using chromosomal microarrays on 75 fetuses referred with apparently isolated CDH, six of which were later reclassified as non-isolated CDH.

RESULTS

The results pinpoint haploinsufficiency of NR2F2 as a cause of CDH and cardiovascular malformations. In addition, the 15q25.2 and 16p11.2 recurrent microdeletions are associated with isolated CDH. By using gene prioritisation and network analysis, we provide strong evidence for several novel dosage-sensitive candidate genes associated with CDH.

CONCLUSIONS

Chromosomal microarray analysis detects submicroscopic CNVs associated with isolated CDH or CDH with cardiovascular malformations.

A BTB domain-containing gene is upregulated by immune challenge

20-Hydroxyecdysone (20E) is an important hormone that regulates the development of insects. Although previous evidence revealed that 20E promotes innate immunity in insects, the mechanism involved is still unclear. In this study, the HaBBP gene from Helicoverpa armigera is cloned, which contains BTB (broad-complex, tramtrack, and bric-a-brac), a BACK (BTB and carboxyl-terminus kelch repeats), and PHR (PAM, highwire, and RPM) domains. RT-PCR analysis of HaBBP and western blot analysis of HaBBP show that the mRNA and protein level are higher in the fat body and hemocytes during the molting and metamorphic stages compared with the feeding stage. HaBBP was upregulated by 20E in hemocytes. Knockdown of the 20E receptor EcR-B1 and the heterodimeric partner ultraspiracle protein USP1 in an epidermal cell line (HaEpi) blocked the transcription of HaBBP. HaBBP is distributed in granulocytes and plasmatocytes. Immune stimulation by Escherichia coli caused the upregulation of HaBBP in both hemocytes and fat body. Thus, HaBBP is regulated by the 20E signaling pathway, and is likely involved in the insect innate immunity.

Recurrent microdeletions of 15q25.2 are associated with increased risk of congenital diaphragmatic hernia, cognitive deficits and possibly Diamond--Blackfan anaemia

BACKGROUND

Congenital diaphragmatic hernia (CDH) can occur in isolation or in association with other abnormalities. We hypothesised that some cases of non-isolated CDH are caused by novel genomic disorders.

METHODS AND RESULTS

In a cohort of >12, 000 patients referred for array comparative genomic hybridisation testing, we identified three individuals-two of whom had CDH--with deletions involving a ∼2.3 Mb region on chromosome 15q25.2. Two additional patients with deletions of this region have been reported, including a fetus with CDH. Clinical data from these patients suggest that recurrent deletions of 15q25.2 are associated with an increased risk of developing CDH, cognitive deficits, cryptorchidism, short stature and possibly Diamond-Blackfan anaemia (DBA). Although no known CDH-associated genes are located on 15q25.2, four genes in this region--CPEB1, AP3B2, HOMER2 and HDGFRP3--have been implicated in CNS development/function and may contribute to the cognitive deficits seen in deletion patients. Deletions of RPS17 may also predispose individuals with 15q25.2 deletions to DBA and associated anomalies.

CONCLUSIONS

Individuals with recurrent deletions of 15q25.2 are at increased risk for CDH and other birth defects. A high index of suspicion should exist for the development of cognitive defects, anaemia and DBA-associated malignancies in these individuals.

Molecular signature of mineralocorticoid receptor signaling in cardiomyocytes: from cultured cells to mouse heart

Excess mineralocorticoid signaling is deleterious for cardiovascular functions, as demonstrated by the beneficial effects of mineralocorticoid receptor (MR) antagonism on morbidity and mortality in patients with heart failure. However, the understanding of signaling pathways after MR activation in the heart remains limited. We performed transcriptomic analyses in the heart of double-transgenic mice with conditional, cardiomyocyte-specific, overexpression of the MR (MRcardio mice) or the glucocorticoid receptor (GR; GRcardio mice). Some of the genes induced in MRcardio mice were selected for comparative evaluation (real time PCR) in vivo in the heart of mice and ex vivo in the MR-expressing cardiomyocyte H9C2 cell line after aldosterone or corticosterone treatment. We demonstrate that chronic MR overexpression in the heart results in a limited number of induced (n = 24) and repressed (n = 22) genes compared with their control littermates. These genes are specifically modulated by MR because there is limited overlap (three induced, four repressed) with the genes that are regulated in the heart of GRcardio mice (compared with control mice: 70 induced, 73 repressed). Interestingly, some MR-induced genes that are up-regulated in vivo in mice are also induced by 24-h aldosterone treatment in H9C2 cells, such as plasminogen activator inhibitor 1 and Serpina-3 (alpha1-antichymotrypsin). The signaling pathways that are affected by long-term activation of MR may be of particular interest to design novel therapeutic targets in cardiac diseases.

Mechanisms of lipase maturation

Lipases are acyl hydrolases that represent a diverse group of enzymes present in organisms ranging from prokaryotes to humans. This article focuses on an evolutionarily related family of extracellular lipases that include lipoprotein lipase, hepatic lipase and endothelial lipase. As newly synthesized proteins, these lipases undergo a series of co- and post-translational maturation steps occurring in the endoplasmic reticulum, including glycosylation and glycan processing, and protein folding and subunit assembly. This article identifies and discusses mechanisms that direct early and late events in lipase folding and assembly. Lipase maturation employs the two general chaperone systems operating in the endoplasmic reticulum, as well as a recently identified lipase-specific chaperone termed lipase maturation factor 1. We propose that the two general chaperone systems act in a coordinated manner early in lipase maturation in order to help create partially folded monomers; lipase maturation factor 1 then facilitates final monomer folding and subunit assembly into fully functional homodimers. Once maturation is complete, the lipases exit the endoplasmic reticulum and are secreted to extracellular sites, where they carry out a number of functions related to lipoprotein and lipid metabolism.

Xenopus BTBD6 and its Drosophila homologue lute are required for neuronal development

BBP proteins constitute a subclass of CUL3 interacting BTB proteins whose in vivo function remains unknown. Here, we show that the Xenopus BBP gene BTBD6 and the single Drosophila homologue of mammalian BBP genes lute are strongly expressed in the developing nervous system. In Xenopus, BTBD6 expression responds positively to proneural and negatively to neurogenic gene overexpression. Knockdown of BTBD6 in Xenopus or loss of Drosophila lute result in embryos with strong defects in late neuronal markers and strongly reduced and disorganized axons while early neural development is unaffected. XBTBD6 knockdown in Xenopus also affects muscle development. Together, these data indicate that BTBD6/lute is required for proper embryogenesis and plays an essential evolutionary conserved role during neuronal development.