PLAG1 expression and target genes in the hypothalamo-pituitary system in male mice

Profiling of differentially expressed MicroRNAs in familial hypercholesterolemia via direct hybridization

Background

Individuals with homozygous familial hypercholesterolemia (HoFH) have a severe clinical problem in their first decade of life, which is not usually present in heterozygous FH (HeFH) individuals. For this latter group of patients, FH diagnosis is mostly severely delayed with a significant increase in the risk of angina, myocardial infarction, peripheral artery disease, stroke, and cardiovascular and all-cause mortality.

Methods

This study used various bioinformatics tools to analyze microarray data and identify critical miRNAs and their target genes associated with FH and its severity. Differentially expressed serum miRNAs from direct hybridization microarray data in three groups of subjects: healthy, HeFH, and HoFH. The differential expressed miRNAs were determined according to a log of fold-change (LFC) <-0.5 or >0.5 and of p < 0.05. Then, we assessed their target genes in silico. Gene ontology (GO) enrichment was applied by Cytoscape. The protein-protein interaction and co-expression network were analyzed by the STRING and GeneMANIA plugins of Cytoscape, respectively.

Results

We identified increased expression of circulating hsa-miR-604, hsa-miR-652-5p, and hsa-miR-4451 as well as reduced expression of hsa-miR-3140-3p, hsa-miR-550a-5p, and hsa-miR-363-3p in both group of FH vs. healthy subjects. Higher levels of hsa-miR-1183, hsa-miR-1185-1-3p, hsa-miR-122-5p, hsa-miR-19a-3p, hsa-miR-345-3p, and hsa-miR-34c-5p were detected in HeFH in respect to HoFH when compared to healthy subjects. Most upregulated miRNAs mainly affected gene related to cardiac myofibrillogenesis, cholesterol synthesis, RNA editing for apolipoprotein B, and associated with LDL-cholesterol levels. In contrast, down-regulated miRNAs mainly affected gene related to plasma biomarker for coronary artery disease, lipids metabolism, cell adhesion and migration, genetic predictors of type 2 diabetes and cholesterol metabolism. The essential genes were primarily enriched in GO regarding biological regulation, intracellular nucleic acid binding, and the KEGG pathway of TGF-β signaling.

Conclusions

The case-control nature of this study precluded the possibility of assessing the predictive role of the identified differentially expressed miRNAs for cardiovascular events. Therefore, the signature of miRNAs reflecting the pathogenesis of both HeFH and HoFH.

The Role of PLAG1 in Mouse Brain Development and Neurogenesis

The pleomorphic adenoma gene 1 (Plag1) is a transcription factor involved in the regulation of growth and cellular proliferation. Here, we report the spatial distribution and functional implications of PLAG1 expression in the adult mouse brain. We identified Plag1 promoter-dependent β-galactosidase expression in various brain structures, including the hippocampus, cortex, choroid plexus, subcommisural organ, ependymal cells lining the third ventricle, medial and lateral habenulae and amygdala. We noted striking spatial-restriction of PLAG1 within the cornu ammonis (CA1) region of the hippocampus and layer-specific cortical expression, with abundant expression noted in all layers except layer 5. Furthermore, our study delved into the role of PLAG1 in neurodevelopment, focusing on its impact on neural stem/progenitor cell proliferation. Loss of Plag1 resulted in reduced proliferation and decreased production of neocortical progenitors in vivo, although ex vivo neurosphere experiments revealed no cell-intrinsic defects in the proliferative or neurogenic capacity of Plag1-deficient neural progenitors. Lastly, we explored potential target genes of PLAG1 in the cortex, identifying that Neurogenin 2 (Ngn2) was significantly downregulated in Plag1-deficient mice. In summary, our study provides novel insights into the spatial distribution of PLAG1 expression in the adult mouse brain and its potential role in neurodevelopment. These findings expand our understanding of the functional significance of PLAG1 within the brain, with potential implications for neurodevelopmental disorders and therapeutic interventions.

Pleomorphic adenoma gene1 in reproduction and implication for embryonic survival in cattle: a review

The pleomorphic adenoma gene1 (PLAG1) encodes a DNA-binding, C2H2 zinc-finger protein which acts as a transcription factor that regulates the expression of diverse genes across different organs and tissues; hence, the name pleomorphic. Rearrangements of the PLAG1 gene, and/or overexpression, are associated with benign tumors and cancers in a variety of tissues. This is best described for pleomorphic adenoma of the salivary glands in humans. The most notable expression of PLAG1 occurs during embryonic and fetal development, with lesser expression after birth. Evidence has accumulated of a role for PLAG1 protein in normal early embryonic development and placentation in mammals. PLAG1 protein influences the expression of the ike growth factor 2 (IGF2) gene and production of IGF2 protein. IGF2 is an important mitogen in ovarian follicles/oocytes, embryos, and fetuses. The PLAG1-IGF2 axis, therefore, provides one pathway whereby PLAG1 protein can influence embryonic survival and pregnancy. PLAG1 also influences over 1,000 other genes in embryos including those associated with ribosomal assembly and proteins. Brahman (Bos indicus) heifers homozygous for the PLAG1 variant, rs109815800 (G > T), show greater fertility than contemporary heifers with either one, or no copy, of the variant. Greater fertility in heifers homozygous for rs109815800 could be the result of early puberty and/or greater embryonic survival. The present review first looks at the broader roles of the PLAG1 gene and PLAG1 protein and then focuses on the emerging role of PLAG1/PLAG1 in embryonic development and pregnancy. A deeper understanding of factors which influence embryonic development is required for the next transformational increase in embryonic survival and successful pregnancy for both in vivo and in vitro derived embryos in cattle.

Cryosectioning and Immunohistochemistry Using Frozen Adult Murine Brain Neural Tissue

Cryopreservation and immunohistochemistry offer a comprehensive, robust, and simple methodology to investigate neural patterning and cellular function. Rapid freezing of the whole brain allows excellent preservation of neural ultrastructure and tissue architecture without destroying sensitive protein epitopes that are often compromised following standard paraffin embedding histological techniques. Here, we present a rapid and simple protocol for employing cryosectioning and subsequent immunohistochemistry in the study of adult murine brain neural tissue.

Goat Pleomorphic Adenoma Gene 1 (PLAG1): mRNA Expression, CNV Detection and Associations with Growth Traits

The pleomorphic adenoma gene 1 (PLAG1) gene, as the major gene responsible for growth, plays a vital role in myogenesis. Meanwhile, the relationship between copy number variation (CNV) of this gene and growth traits in goats remains unclear. Therefore, this study investigated four aspects: bioinformatics analysis, mRNA expression (n = 6), CNV detection (n = 224), and association analysis. The findings indicated that the gene had a large number of conserved motifs, and the gene expression level was higher in fetal goats than in adult goats. Three CNV loci were selected from the database, among which CNV1 was located in the bidirectional promoter region and was associated with goat growth traits. CNV analysis showed that CNV2 and CNV3 of the PLAG1 gene were associated with growth traits such as body weight, heart girth, height at hip cross, and hip width (p < 0.05), with CNV1 loss genotype being the superior genotype, and CNV2 and CNV3 median and gain genotypes of being superior genotypes. This finding further confirms that the PLAG1 gene is the dominant gene for growth traits, which will serve as theoretical guidance for goat breeding.

Effect of Pleomorphic Adenoma Gene 1 Deficiency on Selected Behaviours in Adult Mice

The proto-oncogene pleomorphic adenoma gene 1 (Plag1) encodes a zinc finger transcription factor. PLAG1 is part of the high motility group AT hook-2 (HGMA2)-PLAG1-insulin-like growth factor 2 (IGF2) pathway that, when disrupted, leads to Silver-Russell syndrome, a severe form of intrauterine growth restriction. With little known about PLAG1's role in normal physiology, this study is the first to characterise the behavioural phenotype of PLAG1-deficient mice. Mice were tested for differences in circadian locomotor activity and body temperature, sleep-like behaviour, anxiety-like behaviour, cognition, social behaviour, and sensorimotor gating. Overall, the behavioural phenotype of the Plag1 knock-out (KO) mice was mild: no significant differences were seen in circadian activity levels, locomotion, object recognition, spatial memory or sociability compared to wild-type mice. However, the cued test of fear conditioning, prepulse inhibition of the startle response and Preyer's reflex test suggest that Plag1 KO mice may have a hearing impairment. This implies that PLAG1 plays an important role in proper functioning and/or development of the neural circuitry behind the auditory processes or interacts with genes involved in those processes.

Deficiency of the transcription factor PLAG1 results in aberrant coiling and morphology of the epididymis

Mice deficient in the transcription factor pleomorphic adenoma gene 1 (PLAG1) exhibit reproductive issues that are characterized, in part, by decreased progressive sperm motility in the male. However, the underlying cause of this impairment is unknown. As epididymal transit is critical for sperm maturation and motility, the morphology of the epididymis of Plag1-deficient mice was investigated and the spatial expression patterns of PLAG1 protein and mRNA were identified. Using X-gal staining and in situ hybridization, PLAG1 was shown to be widely expressed in both the epithelium and stroma in all regions of the mouse epididymis. Interestingly, the X-gal staining pattern was markedly different in the cauda, where it could be suggestive of PLAG1 secretion into the epididymal lumen. At all ages investigated, the morphology of epididymides from Plag1 knockout (KO) mice was aberrant; the tubule failed to elongate and coil, particularly in the corpus and cauda, and the cauda was malformed, lacking its usual bulbous shape. Moreover, the epididymides from Plag1 KO mice were significantly reduced in size relative to body weight. In 20% of Plag1-deficient mice, the left testicle and epididymis were lacking. The impaired morphogenesis of the epididymal tubule is likely to be a major contributing factor to the fertility problems observed in male Plag1-deficient mice. These results also establish PLAG1 as an important regulator of male reproduction, not only through its involvement in testicular sperm production, but also via its role in the development and function of the epididymis.

The PLAG1 mRNA expression analysis among genetic variants and relevance to growth traits in Chinese cattle

Pleomorphic adenoma gene 1 (PLAG1) encodes a developmentally regulated zinc finger protein, locating in growth-related QTNs. The mRNA expression of this gene was investigated in different tissues and from two different developmental periods, whilst to explore the functions of PLAG1 in growth traits of cattle. The results showed that PLAG1 was expressed in all examined tissues. However, PLAG1 expression levels in all examined tissues were significantly different between the 5-month fetus and 36-month adult cattle. Our juvenile results indicated PLAG1 is primarily expressed in embryonic tissues of Chinese cattle. Furthermore, two variations were identified. Association analysis revealed that the two variations were associated with growth traits (p < 0.05 or p < 0.01). These new findings provide a comprehensive overview of the critical roles of PLAG1 in growth traits modulation and can be highlighted as candidate molecular markers in cattle breeding.