scholarly journals The Interaction between Bmal1 and Per2 in Mouse BMSC Osteogenic Differentiation

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Haiya Zhuo ◽  
Yuhong Wang ◽  
Qing Zhao

The circadian clock is a system that controls endogenous time of organisms, and it regulates the physiology and behavior of bodies. The transcription factors Brain and Muscle ARNT-like Protein 1 (BMAL1) and Period2 (Per2) are components of the circadian clock, and they play vital roles in circadian clock function. Both Bmal1−/− mice and Per2−/− mice display obvious bone volume changes. In this study, we inhibited the expression of Bmal1 in bone marrow-derived mesenchymal stem cells (BMSCs) using a lentiviral vector harboring RNAi sequences, which increased the osteogenic differentiation capability of BMSCs. We also suppressed Per2 gene expression using an adenovirus vector harboring RNAi sequences, and similarly, the osteogenic differentiation ability of BMSCs was enhanced. Furthermore, when both Bmal1 and Per2 gene expression was suppressed in BMSCs by lentiviral and adenoviral interference, the osteogenic differentiation capability was stronger than that in BMSCs following single-gene inhibition. Our data support that both Bmal1 and Per2 play negative roles in BMSC osteogenic differentiation and that Bmal1 and Per2 have a synergistic effect on the osteogenic differentiation of BMSCs.

2020 ◽  
Vol 477 (16) ◽  
pp. 3091-3104 ◽  
Author(s):  
Luciana E. Giono ◽  
Alberto R. Kornblihtt

Gene expression is an intricately regulated process that is at the basis of cell differentiation, the maintenance of cell identity and the cellular responses to environmental changes. Alternative splicing, the process by which multiple functionally distinct transcripts are generated from a single gene, is one of the main mechanisms that contribute to expand the coding capacity of genomes and help explain the level of complexity achieved by higher organisms. Eukaryotic transcription is subject to multiple layers of regulation both intrinsic — such as promoter structure — and dynamic, allowing the cell to respond to internal and external signals. Similarly, alternative splicing choices are affected by all of these aspects, mainly through the regulation of transcription elongation, making it a regulatory knob on a par with the regulation of gene expression levels. This review aims to recapitulate some of the history and stepping-stones that led to the paradigms held today about transcription and splicing regulation, with major focus on transcription elongation and its effect on alternative splicing.


2017 ◽  
Vol 4 (2) ◽  
Author(s):  
NEHA SINGH ◽  
INDERJEET BHOGAL ◽  
ABHISHEK KUMAR ◽  
PUNIT TYAGI ◽  
GIRIJA SIKARWAR ◽  
...  

Acclimatization is a process that occurs in individual cells to a drastic change in micro and macro environments. When an organism is subjected to a new environment or a change in its normal growing conditions, the cellular mechanisms initiate a warning sign and over a period of time or over generations the acquired, modified traits are being communicated and fixed as a new trait. If there is lack of equilibrium within the cell due to over expression of a single gene or network of associated genes either manmade or due to mutations, the organism or plant tries to fix it by initiating gene regulatory mechanisms. According to our neutral theory of gene expression, always a cell tries to maintain its pH by modifying its cytosol through altered gene expression. In the present investigation, 198 AtMYB genes were analyzed and found to play an intrinsic photosystem linked network of 38 nodes where MYB being regulated by a set of 48 miRNAs. Members of the network have evidence-based link to energy related mechanisms. Altering gene expression to an extent where, the cell may not be able to fix it or a trait, which requires excessive energy loss escorts the organism’s gene regulation by breakdown of the introduced sequence over few generations. Events with constitutive overexpression may suffer poor performance over the years based on gene network prevailing in the crop of interest. Hence, network rewiring with minimal energy expenses is concerned.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Guiomar Martín ◽  
Yamile Márquez ◽  
Federica Mantica ◽  
Paula Duque ◽  
Manuel Irimia

Abstract Background Alternative splicing (AS) is a widespread regulatory mechanism in multicellular organisms. Numerous transcriptomic and single-gene studies in plants have investigated AS in response to specific conditions, especially environmental stress, unveiling substantial amounts of intron retention that modulate gene expression. However, a comprehensive study contrasting stress-response and tissue-specific AS patterns and directly comparing them with those of animal models is still missing. Results We generate a massive resource for Arabidopsis thaliana, PastDB, comprising AS and gene expression quantifications across tissues, development and environmental conditions, including abiotic and biotic stresses. Harmonized analysis of these datasets reveals that A. thaliana shows high levels of AS, similar to fruitflies, and that, compared to animals, disproportionately uses AS for stress responses. We identify core sets of genes regulated specifically by either AS or transcription upon stresses or among tissues, a regulatory specialization that is tightly mirrored by the genomic features of these genes. Unexpectedly, non-intron retention events, including exon skipping, are overrepresented across regulated AS sets in A. thaliana, being also largely involved in modulating gene expression through NMD and uORF inclusion. Conclusions Non-intron retention events have likely been functionally underrated in plants. AS constitutes a distinct regulatory layer controlling gene expression upon internal and external stimuli whose target genes and master regulators are hardwired at the genomic level to specifically undergo post-transcriptional regulation. Given the higher relevance of AS in the response to different stresses when compared to animals, this molecular hardwiring is likely required for a proper environmental response in A. thaliana.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yanlei Yue ◽  
Ze Jiang ◽  
Enoch Sapey ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  

Abstract Background In soybean, some circadian clock genes have been identified as loci for maturity traits. However, the effects of these genes on soybean circadian rhythmicity and their impacts on maturity are unclear. Results We used two geographically, phenotypically and genetically distinct cultivars, conventional juvenile Zhonghuang 24 (with functional J/GmELF3a, a homolog of the circadian clock indispensable component EARLY FLOWERING 3) and long juvenile Huaxia 3 (with dysfunctional j/Gmelf3a) to dissect the soybean circadian clock with time-series transcriptomal RNA-Seq analysis of unifoliate leaves on a day scale. The results showed that several known circadian clock components, including RVE1, GI, LUX and TOC1, phase differently in soybean than in Arabidopsis, demonstrating that the soybean circadian clock is obviously different from the canonical model in Arabidopsis. In contrast to the observation that ELF3 dysfunction results in clock arrhythmia in Arabidopsis, the circadian clock is conserved in soybean regardless of the functional status of J/GmELF3a. Soybean exhibits a circadian rhythmicity in both gene expression and alternative splicing. Genes can be grouped into six clusters, C1-C6, with different expression profiles. Many more genes are grouped into the night clusters (C4-C6) than in the day cluster (C2), showing that night is essential for gene expression and regulation. Moreover, soybean chromosomes are activated with a circadian rhythmicity, indicating that high-order chromosome structure might impact circadian rhythmicity. Interestingly, night time points were clustered in one group, while day time points were separated into two groups, morning and afternoon, demonstrating that morning and afternoon are representative of different environments for soybean growth and development. However, no genes were consistently differentially expressed over different time-points, indicating that it is necessary to perform a circadian rhythmicity analysis to more thoroughly dissect the function of a gene. Moreover, the analysis of the circadian rhythmicity of the GmFT family showed that GmELF3a might phase- and amplitude-modulate the GmFT family to regulate the juvenility and maturity traits of soybean. Conclusions These results and the resultant RNA-seq data should be helpful in understanding the soybean circadian clock and elucidating the connection between the circadian clock and soybean maturity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kulisara Marupanthorn ◽  
Chairat Tantrawatpan ◽  
Pakpoom Kheolamai ◽  
Duangrat Tantikanlayaporn ◽  
Sirikul Manochantr

AbstractMesenchymal stem cells (MSCs) are important in regenerative medicine because of their potential for multi-differentiation. Bone marrow, chorion and placenta have all been suggested as potential sources for clinical application. However, the osteogenic differentiation potential of MSCs derived from chorion or placenta is not very efficient. Bone morphogenetic protein-2 (BMP-2) plays an important role in bone development. Its effect on osteogenic augmentation has been addressed in several studies. Recent studies have also shown a relationship between miRNAs and osteogenesis. We hypothesized that miRNAs targeted to Runt-related transcription factor 2 (Runx-2), a major transcription factor of osteogenesis, are responsible for regulating the differentiation of MSCs into osteoblasts. This study examines the effect of BMP-2 on the osteogenic differentiation of MSCs isolated from chorion and placenta in comparison to bone marrow-derived MSCs and investigates the role of miRNAs in the osteogenic differentiation of MSCs from these sources. MSCs were isolated from human bone marrow, chorion and placenta. The osteogenic differentiation potential after BMP-2 treatment was examined using ALP staining, ALP activity assay, and osteogenic gene expression. Candidate miRNAs were selected and their expression levels during osteoblastic differentiation were examined using real-time RT-PCR. The role of these miRNAs in osteogenesis was investigated by transfection with specific miRNA inhibitors. The level of osteogenic differentiation was monitored after anti-miRNA treatment. MSCs isolated from chorion and placenta exhibited self-renewal capacity and multi-lineage differentiation potential similar to MSCs isolated from bone marrow. BMP-2 treated MSCs showed higher ALP levels and osteogenic gene expression compared to untreated MSCs. All investigated miRNAs (miR-31, miR-106a and miR148) were consistently downregulated during the process of osteogenic differentiation. After treatment with miRNA inhibitors, ALP activity and osteogenic gene expression increased over the time of osteogenic differentiation. BMP-2 has a positive effect on osteogenic differentiation of chorion- and placenta-derived MSCs. The inhibition of specific miRNAs enhanced the osteogenic differentiation capacity of various MSCs in culture and this strategy might be used to promote bone regeneration. However, further in vivo experiments are required to assess the validity of this approach.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Katharina Beer ◽  
Mariela Schenk ◽  
Charlotte Helfrich-Förster ◽  
Andrea Holzschuh

AbstractLife on earth adapted to the daily reoccurring changes in environment by evolving an endogenous circadian clock. Although the circadian clock has a crucial impact on survival and behavior of solitary bees, many aspects of solitary bee clock mechanisms remain unknown. Our study is the first to show that the circadian clock governs emergence in Osmia bicornis, a bee species which overwinters as adult inside its cocoon. Therefore, its eclosion from the pupal case is separated by an interjacent diapause from its emergence in spring. We show that this bee species synchronizes its emergence to the morning. The daily rhythms of emergence are triggered by temperature cycles but not by light cycles. In contrast to this, the bee’s daily rhythms in locomotion are synchronized by light cycles. Thus, we show that the circadian clock of O. bicornis is set by either temperature or light, depending on what activity is timed. Light is a valuable cue for setting the circadian clock when bees have left the nest. However, for pre-emerged bees, temperature is the most important cue, which may represent an evolutionary adaptation of the circadian system to the cavity-nesting life style of O. bicornis.


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