Up-regulation of miR-10a-5p expression inhibits the proliferation and differentiation of neural stem cells by targeting Chl1.

Neural tube defects (NTDs) are characterized by the failure of neural tube closure during embryogenesis and are considered the most common and severe central nervous system anomalies during early development. Recent microRNA (miRNA) expression profiling studies have revealed that the dysregulation of several miRNAs plays an important role in retinoic acid (RA)-induced NTDs. However, the molecular functions of these miRNAs in NTDs remain largely unidentified. Here, we show that miR-10a-5p is significantly upregulated in RA-induced NTDs and results in reduced cell growth due to cell cycle arrest and dysregulation of cell differentiation. Moreover, the cell adhesion molecule L1-like ( Chl1) is identified as a direct target of miR-10a-5p in neural stem cells (NSCs) in vitro, and its expression is reduced in RA-induced NTDs. siRNA-mediated knockdown of intracellular Chl1 affects cell proliferation and differentiation similar to those of miR-10a-5p overexpression, which further leads to the inhibition of the expressions of downstream ERK1/2 MAPK signaling pathway proteins. These cellular responses are abrogated by either increased expression of the direct target of miR-10a-5p ( Chl1) or an ERK agonist such as honokiol. Overall, our study demonstrates that miR-10a-5p plays a major role in the process of NSC growth and differentiation by directly targeting Chl1, which in turn induces the downregulation of the ERK1/2 cascade, suggesting that miR-10a-5p and Chl1 are critical for NTD formation in the development of embryos.

Polymorphisms of Placental Iodothyronine Deiodinase Genes in a Rural Area of Northern China with High Prevalence of Neural Tube Defects.

INTRODUCTION: We have reported that high total homocysteine and the coexistence of inadequate thyroid hormones in maternal serum increase the risk of fetal neural tube defects (NTDs). Placental iodothyronine deiodinases (DIOs: DIO1, DIO2, and DIO3) play a role in regulating the conversions between different forms of maternal thyroid hormones. This study hypothesized that single nucleotide polymorphisms (SNPs) in placental DIOs genes could be related to NTDs. METHODS: We performed a case-control study from 2007 to 2009 that included pregnant women from Lüliang, Shanxi Province, China. Nine distinct SNPs in DIOs genes were analyzed, and placental samples were obtained from 83 pregnant women with NTD fetuses and 90 pregnant women with normal fetuses. The nine SNPs were analyzed using the Cochran-Armitage test and the Fisher's exact test. RESULTS: There were no statistically significant differences between case and control in the nine SNPs of DIOs (p > 0.05). CONCLUSIONS: The results of this study suggested that SNPs of DIO genes in the placenta among pregnant women have no statistically significant difference between the two groups, suggesting that other factors might be involved in metabolism of maternal thyroid hormone provided to fetuses, such as epigenetic modification of methylation and homocysteinylation and genomic imprinting in the placenta. Further functional studies on placenta samples are necessary.

Transcriptome analysis of immune-related genes of Asian corn borer (Ostrinia furnacalis [Guenée]) after oral bacterial infection.

The Asian corn borer (Ostrinia furnacalis) is an important agricultural pest causing serious damage to economic crops, such as corn and sorghum. The gut is the first line of defense against pathogens that enter through the mouth. Staphylococcus aureus was used to infect the O. furnacalis midgut to understand the midgut immune mechanism against exogenous pathogens to provide new ideas and methods for the prevention and control of O. furnacalis. A sequencing platform was used for genome assembly and gene expression. The unigene sequences were annotated and functionally classified by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Significant differences were found in the induced expression profiles before and after infection. Some differentially expressed genes have important relations with lipid metabolism and immune mechanism, suggesting that they play an important role in the innate immune response of O. furnacalis. Furthermore, quantitative real-time polymerase chain reaction assay was used to identify the key genes involved in the signaling pathway, and the expression patterns of these key genes were confirmed. The results could help study the innate immune system of lepidopteran insects and provide theoretical support for the control of related pests and the protection of beneficial insects.

Correction: Mei et al. Bombyx mori C-Type Lectin (BmIML-2) Inhibits the Proliferation of B. mori Nucleopolyhedrovirus (BmNPV) through Involvement in Apoptosis. Int. J. Mol. Sci. 2022, 23, 8369.

In the original publication [...].

Peptidoglycan recognition protein 6 (PGRP6) from Asian corn borer, Ostrinia furnacalis (Guenée) serve as a pattern recognition receptor in innate immune response.

Peptidoglycan recognition proteins (PGRPs) recognize invading microbes via detecting peptidoglycans from microbial cell walls. PGRPs are highly conserved from insects to vertebrates and all play roles during the immune defensive response. Ten putative PGRPs have been identified through transcriptome analysis in the Asian corn borer, Ostrinia furnacalis (Guenée). Whereas, the biochemical functions of most of them have not yet been elucidated. In this study, we found PGRP6 messenger RNA exhibited extremely high expression levels in the midgut, and its transcript level increased dramatically upon bacterial infection. Moreover, the enzyme-linked immunosorbent assay indicated recombinant PGRP6 exhibited a strong binding affinity to peptidoglycans from Micrococcus luteus and Bacillus subtilis, which could agglutinate M. luteus and yeast Pichia pastoris. Additionally, we demonstrated that PGRP6 was involved in the pathway of antimicrobial peptides synthesis, but could not enhance encapsulation and melanization of hemocytes. Overall, our results indicated that O. furnacalis PGRP6 serves as a pattern recognition receptor and detects peptidoglycans from microbes to initiate the immune response.

Bombyx mori C-Type Lectin (BmIML-2) Inhibits the Proliferation of B. mori Nucleopolyhedrovirus (BmNPV) through Involvement in Apoptosis.

C-type lectins (CTLs) are widely distributed in mammals, insects, and plants, which act as pattern recognition receptors (PRRs) to recognize pathogens and initiate immune responses. In this study, we identified a C-type lectin gene called BmIML-2 from the silkworm Bombyx mori. Its open reading frame (ORF) encodes 314 amino acids, which contain dual tandem C-type lectin-like domain (CTLD). BmIML-2 is highly expressed in the fat body and is significantly induced at 24 h after BmNPV infection. Moreover, overexpression of BmIML-2 dramatically inhibited the proliferation of BmNPV, and knockdown assay via siRNA further validated the inhibition of BmIML-2 on viral proliferation. In addition, transcript level detection of apoptosis-related genes and observation of apoptosis bodies implied that overexpression of BmIML-2 promoted BmNPV-induced apoptosis. Immunofluorescence analysis indicated that BmIML-2 distributed throughout the cytoplasm and was slightly concentrated in the cell membrane. Taken together, our results suggest that BmIML-2 could inhibit in the proliferation of BmNPV by facilitating cell apoptosis.

A Pattern Recognition Receptor C-type Lectin-S6 (CTL-S6) is Involved in the Immune Response in the Silkworm (Lepidoptera: Bombycidae).

Insect innate immunity is initiated by the special recognition and binding of the foreign pathogens, which is accomplished by the pattern recognition receptors (PRRs). As an important type of PRRs, C-type lectins (CTLs) play various roles in insect innate immunity, including pathogen recognition, stimulation of prophenoloxidase, regulation of cellular immunity and so on. In this study, we have cloned the full-length cDNA of a CTL gene named CTL-S6 from the silkworm, Bombyx mori. The open reading frame (ORF) of B. mori CTL-S6 encodes 378 amino acids, which contain a secretion signal peptide. The mRNA of CTL-S6 exhibited the highest transcriptional level in the midgut. Its transcriptional level increased dramatically in fat body and hemocytes upon Escherichia coli or Micrococcus luteus challenge. Purified recombinant CTL-S6 could bind to bacterial cell wall components, including peptidoglycan (PGN, from Bacillus subtilis) and lipopolysaccharide (LPS, from E. coli 0111:B4), and recombinant CTL-S6 was involved in the encapsulation and melanization of hemocytes. Furthermore, the addition of recombinant CTL-S6 to the hemolymph of silkworm resulted in a significant increase in phenoloxidase activity. Overall, our results indicated that B. mori CTL-S6 may serve as a PRR for the recognition of foreign pathogens, prophenoloxidase pathway stimulation and involvement in the innate immunity.

[Advance in research on epigenetic clock/age and its implications].

The progress of epigenetic research has led to the discovery and confirmation of age-related markers based on DNA methylation. These DNA methylation indices are called "epigenetic clock/age". The concept of "epigenetic clock/age" and the establishment of its evaluation system are helpful to solve some of the long-standing problems in the field of life and medicine. When facing the current global aging, it is of great significance to refer to the comprehensive health parameters to determine the biological age and life span of an individual, and thus to design a plan to slow down the process of life cycle. This paper has summarized the concept and development of "epigenetic clock/age" in recent years.

Simultaneous Amino Acid Analysis Based on 19F NMR Using a Modified OPA-Derivatization Method.

To provide alternative methods of analyzing amino acids without liquid chromatography, 19F NMR-based simultaneous and individual detection methods for amino acids using o-phthalaldehyde (OPA)-based 19F labeling have been developed. Since the chemical shifts of almost all 19F-labeled amino acids differ from each other, and they can be discriminated on the 19F NMR spectrum, simultaneous detection of amino acids has been successfully demonstrated. The discrimination pattern of the peak identical to that of the 19F-labeled amino acids was largely dependent on the chemical structure of the thiols having 19F nuclei, strongly suggesting that there is a large potential for clearer discrimination of amino acids by optimizing the thiol structure and/or combined use of thiols.

The effect of folic acid deficiency on FGF pathway via Brachyury regulation in neural tube defects.

Folate deficiency in early development leads to disturbance in multiple processes, including neurogenesis during which fibroblast growth factor (FGF) pathway is one of the crucial pathways. Whether folic acid (FA) directly affects FGF pathways to influence neurodevelopment and the possible mechanism remains unclear. In this study, we presented evidence that in human FA-insufficient encephalocele, the FGF pathway was interfered. Furthermore, in Brachyury knockout mice devoid of such T-box transcription factors regulating embryonic neuromesodermal bipotency and a key component of FGF pathway, change in expression of Brachyury downstream targets, activator Fgf8 and suppressor dual specificity phosphatase 6 was detected, along with the reduction in expression of other key FGF pathway genes. By using a FA-deficient cell model, we further demonstrated that decrease in Brachyury expression was through alteration in hypermethylation at the Brachyury promoter region under FA deficiency conditions, and suppression of Brachyury promoted the inactivation of the FGF pathway. Correspondingly, FA supplementation partially reverses the effects seen in FA-deficient embryoid bodies. Lastly, in mice with maternal folate-deficient diets, aberrant FGF pathway activity was found in fetal brain dysplasia. Taken together, our findings highlight the effect of FA on FGF pathways during neurogenesis, and the mechanism may be due to the low expression of Brachyury gene via hypermethylation under FA-insufficient conditions.-Chang, S., Lu, X., Wang, S., Wang, Z., Huo, J., Huang, J., Shangguan, S., Li, S., Zou, J., Bao, Y., Guo, J., Wang, F., Niu, B., Zhang, T., Qiu, Z., Wu, J., Wang, L. The effect of folic acid deficiency on FGF pathway via Brachyury regulation in neural tube defects.

Spin colossal magnetoresistance in an antiferromagnetic insulator.

Colossal magnetoresistance (CMR) refers to a large change in electrical conductivity induced by a magnetic field in the vicinity of a metal-insulator transition and has inspired extensive studies for decades1,2. Here we demonstrate an analogous spin effect near the Néel temperature, TN = 296 K, of the antiferromagnetic insulator Cr2O3. Using a yttrium iron garnet YIG/Cr2O3/Pt trilayer, we injected a spin current from the YIG into the Cr2O3 layer and collected, via the inverse spin Hall effect, the spin signal transmitted into the heavy metal Pt. We observed a two orders of magnitude difference in the transmitted spin current within 14 K of the Néel temperature. This transition between spin conducting and non-conducting states was also modulated by a magnetic field in isothermal conditions. This effect, which we term spin colossal magnetoresistance (SCMR), has the potential to simplify the design of fundamental spintronics components, for instance, by enabling the realization of spin-current switches or spin-current-based memories.

Reversible photo-cross-linking of the GCN4 peptide containing 3-cyanovinylcarbazole amino acid to double-stranded DNA.

Interaction analysis in vivo greatly promotes the analyses and understanding of biological functions. The interaction between DNA and peptides or proteins is very important in terms of readout and amplifying information from genomic DNA. In this study, we designed and synthesized a photo-cross-linkable amino acid, l-3-cyanovinlycarbazole amino acid (l-CNVA), to double-stranded DNA. Reversible photo-cross-linking between DNA and peptides containing CNVA, having 3-cyanovinylcarbazole moieties capable of photo-cross-linking to nucleic acids, was demonstrated. As a result, it was shown that the GCN4 peptide, containing CNVA, can be photo-cross-linked to DNA, and its adduct was photo-split into the original peptide and DNA with 312 nm-irradiation. This is the first report that reversibly manipulates photo-crosslinking between double stranded DNA and peptides. In addition, this reversible photo-cross-linking, using l-CNVA, is faster and with higher yield than that using diazirine and psoralen.

Folate deficiency facilitates recruitment of upstream binding factor to hot spots of DNA double-strand breaks of rRNA genes and promotes its transcription.

The biogenesis of ribosomes in vivo is an essential process for cellular functions. Transcription of ribosomal RNA (rRNA) genes is the rate-limiting step in ribosome biogenesis controlled by environmental conditions. Here, we investigated the role of folate antagonist on changes of DNA double-strand breaks (DSBs) landscape in mouse embryonic stem cells. A significant DSB enhancement was detected in the genome of these cells and a large majority of these DSBs were found in rRNA genes. Furthermore, spontaneous DSBs in cells under folate deficiency conditions were located exclusively within the rRNA gene units, representing a H3K4me1 hallmark. Enrichment H3K4me1 at the hot spots of DSB regions enhanced the recruitment of upstream binding factor (UBF) to rRNA genes, resulting in the increment of rRNA genes transcription. Supplement of folate resulted in a restored UBF binding across DNA breakage sites of rRNA genes, and normal rRNA gene transcription. In samples from neural tube defects (NTDs) with low folate level, up-regulation of rRNA gene transcription was observed, along with aberrant UBF level. Our results present a new view by which alterations in folate levels affects DNA breakage through epigenetic control leading to the regulation of rRNA gene transcription during the early stage of development.

Modeling and simulation of dielectrophoretic collective dynamics in a suspension of polarizable particles under the action of a gradient AC electric field.

When a suspension of polarizable particles is subjected to a gradient AC electric field, the particles exhibit collective motion due to an interaction between the dipole induced in the particles and the spatial gradient of the electric field; this is known as dielectrophoresis. In the present study, the collective dynamics of suspended particles in a parallel-plate electric chamber was investigated by simulating numerically the trajectories of individual particles under the action of combined dielectrophoretic and dipole-dipole interparticle forces. The particles were transported by the dielectrophoretic forces toward the grounded electrodes. Before long, when the particles approached the site of the minimum field strength, attractive/repulsive interparticle forces became dominant and acted among the particles attempting to form a column-like cluster, having the particles distribution in concentric circles in its cross-section, in line with the centerline of the grounded electrodes. Our results also well reproduced the transient particle aggregation that was observed experimentally.

Tunable Sign Change of Spin Hall Magnetoresistance in Pt/NiO/YIG Structures.

Spin Hall magnetoresistance (SMR) has been investigated in Pt/NiO/YIG structures in a wide range of temperature and NiO thickness. The SMR shows a negative sign below a temperature that increases with the NiO thickness. This is contrary to a conventional SMR theory picture applied to the Pt/YIG bilayer, which always predicts a positive SMR. The negative SMR is found to persist even when NiO blocks the spin transmission between Pt and YIG, indicating it is governed by the spin current response of the NiO layer. We explain the negative SMR by the NiO "spin flop" coupled with YIG, which can be overridden at higher temperature by positive SMR contribution from YIG. This highlights the role of magnetic structure in antiferromagnets for transport of pure spin current in multilayers.

Magnon Polarons in the Spin Seebeck Effect.

Sharp structures in the magnetic field-dependent spin Seebeck effect (SSE) voltages of Pt/Y_{3}Fe_{5}O_{12} at low temperatures are attributed to the magnon-phonon interaction. Experimental results are well reproduced by a Boltzmann theory that includes magnetoelastic coupling. The SSE anomalies coincide with magnetic fields tuned to the threshold of magnon-polaron formation. The effect gives insight into the relative quality of the lattice and magnetization dynamics.

Tumor-targeted in vivo gene silencing via systemic delivery of cRGD-conjugated siRNA.

RNAi technology is taking strong position among the key therapeutic modalities, with dozens of siRNA-based programs entering and successfully progressing through clinical stages of drug development. To further explore potentials of RNAi technology as therapeutics, we engineered and tested VEGFR2 siRNA molecules specifically targeted to tumors through covalently conjugated cyclo(Arg-Gly-Asp-d-Phe-Lys[PEG-MAL]) (cRGD) peptide, known to bind αvß3 integrin receptors. cRGD-siRNAs were demonstrated to specifically enter and silence targeted genes in cultured αvß3 positive human cells (HUVEC). Microinjection of zebrafish blastocysts with VEGFR2 cRGD-siRNA resulted in specific inhibition of blood vessel growth. In tumor-bearing mice, intravenously injected cRGD-siRNA molecules generated no innate immune response and bio-distributed to tumor tissues. Continuous systemic delivery of two different VEGFR2 cRGD-siRNAs resulted in down-regulation of corresponding mRNA (55 and 45%) and protein (65 and 45%) in tumors, as well as in overall reduction of tumor volume (90 and 70%). These findings demonstrate strong potential of cRGD-siRNA molecules as anti-tumor therapy.

[Genetic analysis and gene mapping of two novel quail-like mutants from the silkworm (Bombyx mori)].

Two novel body marking mutants were discovered during silkworm (Bombyx mori) breeding. The mutants have no obvious eye-spots compared with normal marking (+) individuals, but their star spots and semilunar markings on dorsal sides are normal, and there are dots and lines with longitudinal wave markings on dorsal sides of the 6th to 7th abdominal segments which consist quail markings in between star spots and semilunar markings. The whole body markings are very similar to that of quail mutant (q); thus these mutants are named as quail-like mutants (q-l). Young larvae of one mutant are in brown color, and develop normally. Their cocoons are regular and uniform in size. Thus, this mutant is designated as brown quail-like (q-lb). Another mutant's larvae are in light purple skin; thus this mutant is named as purple quail-like (q-lp). They take little amount of mulberry leaves, and are weak and develop slowly and unevenly. Their larval bodies and cocoons are small. Genetic analysis revealed that both q-lb and q-lp were recessive genes, and they were allelic, with q-lb recessive to q-lp. These genes are different from quail mutant (q) and located on the chromosome 8 after tested by the morphological markers, P3(2), p(2), Ze(3), L(4), re(5), E(6), q(7), I-a(9), ms(12), ch(13), oa(14), cts(16), mln(18), msn(19), rb(21) and so(26) and SSR markers.

Revealing the Role of the Tetragonal Distortion in the Metal-Insulator Transition of Co- and Fe-Doped NiS.

Although the NiS exhibits the most widely adjustable metal-to-insulator (MIT) properties among the chalcogenides, the mechanisms, with respect to the regulations in their critical temperatures (TMIT), are yet unclear. Herein, we demonstrate the overlooked role associated with the structurally tetragonal distortion in elevating the TMIT of NiS; this is in distinct contrast to the previously expected hybridization and bandwidth regulations that usually reduces TMIT. Compared to the perspective of structure distortions, the orbital hybridization and band regulation of NiS are ∼19 times more effective adjustment in TMIT. As a result, the respective abruptions in both the electrical and thermal resistive switches across the TMIT of NiS can be better preserved in the low-temperature range (<273 K), shedding light on their optimum usage at cryogenic temperatures.

Bombyx mori triose-phosphate transporter protein inhibits Bombyx mori nucleopolyhedrovirus infection by reducing the cell glycolysis pathway.

Bombyx mori triose-phosphate transporter protein (BmTPT) is a member of the solute carrier (SLC) family. Its main function is to transport triose phosphate between intracellular and extracellular. In this study, BmTPT was cloned and characterised from the fat body of the silkworm Bombyx mori, resulting in an open reading frame (ORF) with a full length of 936 bp, which can encode 311 amino acid residues and has eight transmembrane structural domains. BmTPT was distributed throughout the cell and deposited the most in the nucleus, and is expressed in all tissues of Bombyx mori. Bombyx mori nucleopolyhedrovirus (BmNPV) infection significantly up-regulated BmTPT expression in immune tissue fat bodies. In addition, overexpression of BmTPT significantly inhibited BmNPV infection and markedly reduced the expression of enzymes related to the cellular glycolytic pathway; on the contrary, down-regulation of BmTPT expression by RNA interference resulted in robust replication of BmNPV and a significant increase in the expression of enzymes related to the cellular glycolytic pathway. This is the first report that BmTPT has antiviral effect in silkworm, and also could result in a lack of energy and raw materials for BmNPV replication and infection through down-regulation of the cellular glycolytic pathway.