Bone mesenchymal stem cells (BMSCs) can be a useful cell resource for developing biological treatment strategies for bone repair and regeneration, and their therapeutic applications hinge on an ...understanding of their physiological characteristics. N⁶-methyl-adenosine (m⁶A) is the most prevalent internal chemical modification of mRNAs and has recently been reported to play important roles in cell lineage differentiation and development. However, little is known about the role of m⁶A modification in the cell differentiation of BMSCs. To address this issue, we investigated the expression of N⁶-adenosine methyltransferases (Mettl3 and Mettl14) and demethylases (Fto and Alkbh5) and found that Mettl3 was upregulated in BMSCs undergoing osteogenic induction. Furthermore, we knocked down
and demonstrated that
knockdown decreased the expression of bone formation-related genes, such as
and
. The alkaline phosphatase (ALP) activity and the formation of mineralized nodules also decreased after
knockdown. RNA sequencing analysis revealed that a vast number of genes affected by
knockdown were associated with osteogenic differentiation and bone mineralization. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis revealed that the phosphatidylinositol 3-kinase/AKT (PI3K-Akt) signaling pathway appeared to be one of the most enriched pathways, and Western blotting results showed that Akt phosphorylation was significantly reduced after
knockdown. Mettl3 has been reported to play an important role in regulating alternative splicing of mRNA in previous research. In this study, we found that
knockdown not only reduced the expression of
but also decreased the level of its splice variants,
and
, in
-deficient BMSCs. These findings might contribute to novel progress in understanding the role of epitranscriptomic regulation in the osteogenic differentiation of BMSCs and provide a promising perspective for new therapeutic strategies for bone regeneration.
Tet-eleven translocation 1 (TET1) is a dioxygenase that plays an important role in decreasing the abundance of DNA methylation and changing the expression levels of specific genes related to ...inflammation.
(Pg.) lipopolysaccharide (LPS) can induce periodontal diseases that present with severe bone loss and collagen fiber destruction accompanied by a high number of M1 macrophages. M1-polarized macrophages are pivotal immune cells that promote the progression of the periodontal inflammatory response, but the function of TET1 during M1 macrophage activation is still unknown. Our results showed that the mRNA and protein expression levels of TET1 decreased in THP-1 cells during M1 macrophage differentiation.
knockdown resulted in a significant decrease in the production of proinflammatory markers such as IL-6, TNF-α, CCL2, and HLA-DR in Pg. LPS/IFN-γ- and
(
) LPS/IFN-γ-induced M1 macrophages. Mechanistically,
knockdown downregulated the activity of the NF-κB signaling pathway. After treatment with the NF-κB inhibitor BAY 11-7082, M1 marker expression showed no significant difference between the
knockdown group and the control group. Taken together, these results suggest that
depletion inhibited Pg. LPS/IFN-γ-induced M1 macrophage polarization through the NF-κB pathway in THP-1 cells.
Elevated ground-level ozone (O
), which is an important aspect of air quality related to public health, has been causing increasing concern. This study investigated the spatiotemporal distribution of ...ground-level O
concentrations in China using a dataset from the Chinese national air quality monitoring network during 2013-2015. This research analyzed the diurnal, monthly and yearly variation of O
concentrations in both sparsely and densely populated regions. In particular, 6 major Chinese cities were selected to allow a discussion of variations in O
levels in detail, Beijing, Chengdu, Guangzhou, Lanzhou, Shanghai, and Urumchi, located on both sides of the Heihe-Tengchong line. Data showed that the nationwide 3-year MDA8 of ground-level O
was 80.26 μg/m
. Ground-level O
concentrations exhibited monthly variability peaking in summer and reaching the lowest levels in winter. The diurnal cycle reached a minimum in morning and peaked in the afternoon. Yearly average O
MDA8 concentrations in Beijing, Chengdu, Lanzhou, and Shanghai in 2015 increased 12%, 25%, 34%, 22%, respectively, when compared with those in 2013. Compared with World Health Organization O
guidelines, Beijing, Chengdu, Guangzhou, and Shanghai suffered O
pollution in excess of the 8-hour O
standard for more than 30% of the days in 2013 to 2015.
Loss- and gain-of-function mutations of the X-linked gene MECP2 (methyl-CpG binding protein 2) lead to severe neurodevelopmental disorders in humans, such as Rett syndrome (RTT) and autism. MeCP2 ...is previously known as a transcriptional repressor by binding to methylated DNA and recruiting histone deacetylase complex (HDAC). Here, we report that MeCP2 regulates gene expression posttranscriptionally by suppressing nuclear microRNA processing. We found that MeCP2 binds directly to DiGeorge syndrome critical region 8 (DGCR8), a critical component of the nuclear microRNA-processing machinery, and interferes with the assembly of Drosha and DGCR8 complex. Protein targets of MeCP2-suppressed microRNAs include CREB, LIMK1, and Pumilio2, which play critical roles in neural development. Gain of function of MeCP2 strongly inhibits dendritic and spine growth, which depends on the interaction of MeCP2 and DGCR8. Thus, control of microRNA processing via direct interaction with DGCR8 represents a mechanism for MeCP2 regulation of gene expression and neural development.
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•MeCP2 directly binds to DiGeorge syndrome critical region 8 (DGCR8)•Interaction of DGCR8 with MeCP2 is independent of the DNA-binding domain of MeCP2•Phosphorylation of MeCP2 regulates an intramolecular switch for binding to DGCR8•MeCP2 regulates dendritic and spine growth via controlling microRNA processing
MeCP2 suppresses microRNA processing by binding to DiGeorge syndrome critical region 8 (DGCR8), a critical component of the nuclear microRNA-processing machinery, and interferes with the assembly of Drosha and DGCR8 complex. Cheng et al. show that MeCP2 strongly inhibits dendritic and spine growth, which depends on the interaction of MeCP2 and DGCR8.
Asset management process and techniques can improve the cost-efficiency, balance the cost and risk, and prolong the service life of the aging switchgears in power grids, which have become ...increasingly important for electric utilities. This paper provides an insight into the recent developments in switchgear asset management and explore future research stream. Accordingly, three directions: condition monitoring, health assessment, and maintenance strategy have been addressed. We first present switchgear condition monitoring indicators and condition evaluation methods utilizing these condition data. Subsequently, we explain health index methodologies to achieve switchgear health assessment and remaining useful life estimation. With these results, we then present the maintenance strategy and life cycle cost optimization methods to address cost-efficient decision making. Finally, the limitation of existing methods and future research trend are discussed. This paper covers various asset management domains, attempting to create a common understanding and fill the gaps among the academic, industry, and technology area.
Messenger RNA (mRNA) holds great potential in developing immunotherapy, protein replacement, and genome editing. In general, mRNA does not have the risk of being incorporated into the host genome and ...does not need to enter the nucleus for transfection, and it can be expressed even in nondividing cells. Therefore, mRNA‐based therapeutics provide a promising strategy for clinical treatment. However, the efficient and safe delivery of mRNA remains a crucial constraint for the clinical application of mRNA therapeutics. Although the stability and tolerability of mRNA can be enhanced by directly retouching the mRNA structure, there is still an urgent need to improve the delivery of mRNA. Recently, significant progress has been made in nanobiotechnology, providing tools for developing mRNA nanocarriers. Nano‐drug delivery system is directly used for loading, protecting, and releasing mRNA in the biological microenvironment and can be used to stimulate the translation of mRNA to develop effective intervention strategies. In the present review, we summarized the concept of emerging nanomaterials for mRNA delivery and the latest progress in enhancing the function of mRNA, primarily focusing on the role of exosomes in mRNA delivery. Moreover, we outlined its clinical applications so far. Finally, the key obstacles of mRNA nanocarriers are emphasized, and promising strategies to overcome these obstacles are proposed. Collectively, nano‐design materials exert functions for specific mRNA applications, provide new perception for next‐generation nanomaterials, and thus revolution of mRNA technology.
Herein, we prepared Fe(II), Zn(II), hydroxylammonium, and hydrazinium pentazolates and investigated their thermal behavior, decomposition kinetics, and thermodynamic activation parameters. The ...thermolysis of metal and non‐metal salts featured three and two mass‐loss stages, respectively, with the decomposition of pentazolate anions occurring at 105–135 °C. Moreover, metal salts exhibited higher thermal safety than non‐metal salts under the same conditions. Iron and zinc pentazolates decomposed at lower temperatures than sodium pentazolate, i. e., Fe(II) and Zn(II) ions promoted the decomposition of pentazolate anions. The obtained results demonstrate that the prepared compounds hold great promise as energetic catalysts for solid propellant decomposition.
Rat hepatitis E virus (rat HEV) was first identified in wild rats and was classified as the species
in the genera
, which is genetically different from the genotypes HEV-1 to HEV-8, which are ...classified as the species
. Although recent reports suggest that rat HEV transmits to humans and causes hepatitis, the infectivity of rat HEV to non-human primates such as cynomolgus and rhesus monkeys remains controversial. To investigate whether rat HEV infects non-human primates, we inoculated one cynomolgus monkey and five rhesus monkeys with a V-105 strain of rat HEV via an intravenous injection. Although no significant elevation of alanine aminotransferase (ALT) was observed, rat HEV RNA was detected in fecal specimens, and seroconversion was observed in all six monkeys. The partial nucleotide sequences of the rat HEV recovered from the rat HEV-infected monkeys were identical to those of the V-105 strain, indicating that the infection was caused by the rat HEV. The rat HEV recovered from the cynomolgus and rhesus monkeys successfully infected both nude and Sprague-Dawley rats. The entire rat HEV genome recovered from nude rats was identical to that of the V-105 strain, suggesting that the rat HEV replicates in monkeys and infectious viruses were released into the fecal specimens. These results demonstrated that cynomolgus and rhesus monkeys are susceptible to rat HEV, and they indicate the possibility of a zoonotic infection of rat HEV. Cynomolgus and rhesus monkeys might be useful as animal models for vaccine development.
Methyl-CpG binding protein 2 (MeCP2) has crucial roles in transcriptional regulation and microRNA processing. Mutations in the MECP2 gene are found in 90% of patients with Rett syndrome, a severe ...developmental disorder with autistic phenotypes. Duplications of MECP2-containing genomic segments cause the MECP2 duplication syndrome, which shares core symptoms with autism spectrum disorders. Although Mecp2-null mice recapitulate most developmental and behavioural defects seen in patients with Rett syndrome, it has been difficult to identify autism-like behaviours in the mouse model of MeCP2 overexpression. Here we report that lentivirus-based transgenic cynomolgus monkeys (Macaca fascicularis) expressing human MeCP2 in the brain exhibit autism-like behaviours and show germline transmission of the transgene. Expression of the MECP2 transgene was confirmed by western blotting and immunostaining of brain tissues of transgenic monkeys. Genomic integration sites of the transgenes were characterized by a deep-sequencing-based method. As compared to wild-type monkeys, MECP2 transgenic monkeys exhibited a higher frequency of repetitive circular locomotion and increased stress responses, as measured by the threat-related anxiety and defensive test. The transgenic monkeys showed less interaction with wild-type monkeys within the same group, and also a reduced interaction time when paired with other transgenic monkeys in social interaction tests. The cognitive functions of the transgenic monkeys were largely normal in the Wisconsin general test apparatus, although some showed signs of stereotypic cognitive behaviours. Notably, we succeeded in generating five F1 offspring of MECP2 transgenic monkeys by intracytoplasmic sperm injection with sperm from one F0 transgenic monkey, showing germline transmission and Mendelian segregation of several MECP2 transgenes in the F1 progeny. Moreover, F1 transgenic monkeys also showed reduced social interactions when tested in pairs, as compared to wild-type monkeys of similar age. Together, these results indicate the feasibility and reliability of using genetically engineered non-human primates to study brain disorders.
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