Conserved Odorant Receptors Involved in Nonanal-Induced Female Attractive Behavior in Two Spodoptera Species.

Moths rely on plant volatiles to locate appropriate plants for feeding and laying eggs. While extensive research has been conducted on the global agricultural pests, Spodoptera frugiperda and Spodoptera litura, their molecular mechanisms for detecting plant volatiles remain mostly unknown. Here, we have demonstrated that nonanal, a common plant volatile, is attractive for both virgin and gravid females of the two species. Second, we have identified a conserved odorant receptor clade (SfruOR47 clade) that is primarily tuned to nonanal. Finally, by three-dimensional (3D) structure prediction, molecular docking, and site-directed mutagenesis, we have revealed that the His57 and Glu61 residues, also shared by other six orthologous ORs, are essential for nonanal binding in SfruOR47 and SlituOR9, indicating the conserved structure and function of ORs in the SfruOR47 clade. These findings offer novel insights into the molecular mechanisms and evolutionary aspects of moth behavior in response to plant volatiles.

cFLIPS regulates alternative NLRP3 inflammasome activation in human monocytes.

The innate immune responses, including inflammasome activation, are paramount for host defense against pathogen infection. In contrast to canonical and noncanonical inflammasome activation, in this study, heat-killed gram-negative bacteria (HK bacteria) were identified as single-step stimulators of the NLRP3 inflammasome in human monocytes, and they caused a moderate amount of IL-1ß to be released from cells. Time course experiments showed that this alternative inflammasome response was finished within a few hours. Further analysis showed that the intrinsically limited NLRP3 inflammasome activation response was due to the negative regulation of caspase-8 by the short isoform of cFLIP (cFLIPs), which was activated by NF-κB. In contrast, overexpressed cFLIPS, but not overexpressed cFLIPL, inhibited the activation of caspase-8 and the release of IL-1ß in response to HK bacteria infection in human monocytes. Furthermore, we demonstrated that TAK1 activity mediated the expression of cFLIPs and was upstream and essential for the caspase-8 cleavage induced by HK bacteria in human monocytes. The functional specificity of cFLIPs and TAK1 revealed unique responses of human monocytes to a noninvasive pathogen, providing novel insights into an alternative regulatory pathway of NLRP3 inflammasome activation.

TRAF6-TAK1-IKKß pathway mediates TLR2 agonists activating "one-step" NLRP3 inflammasome in human monocytes.

Gram-positive bacterial infection causes high morbidity and mortality worldwide, while the underlying mechanism for host sensing bacterial components and initiating immune responses remains elusive. The NLRP3 inflammasome is a cytosolic multi-protein complex sensing a broad spectrum of endogenous danger signals and environmental irritants. In contrast to canonical NLRP3 inflammasome activation that needs both priming and activation signals, Lipopolysaccharide (LPS) from gram-negative bacteria activates the "one-step" NLRP3 inflammasome in human monocytes, which relies on the TLR4-TRIF-Caspase-8 signaling. Here, we show that in human monocytes, TLR2 agonists such as heat-killed gram-positive bacteria, peptidoglycan (PGN) or synthetic bacterial lipoprotein analog Pam3CysSerLys4 (Pam3CSK4) are able to induce the "one-step" NLRP3 inflammasome activation. Using genetic targeting and pharmacological inhibition approaches, it was found that TLR2 propagates signal through TRAF6, TAK1 and IKKß, ultimately activated NLRP3 independent of RelA. In addition, IKKß interacts with NLRP3 directly and affects NLRP3 inflammasome activation. These results reveal the signaling cascade downstream of TLR2 upon sensing gram-positive bacterial infection and activating the "one-step" NLRP3 inflammasome in human monocytes, which provides clue for controlling gram-positive bacterial infection-related inflammation.

SARS-CoV-2 spike engagement of ACE2 primes S2' site cleavage and fusion initiation.

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has resulted in tremendous loss worldwide. Although viral spike (S) protein binding of angiotensin-converting enzyme 2 (ACE2) has been established, the functional consequences of the initial receptor binding and the stepwise fusion process are not clear. By utilizing a cell-cell fusion system, in complement with a pseudoviral infection model, we found that the spike engagement of ACE2 primed the generation of S2' fragments in target cells, a key proteolytic event coupled with spike-mediated membrane fusion. Mutagenesis of an S2' cleavage site at the arginine (R) 815, but not an S2 cleavage site at arginine 685, was sufficient to prevent subsequent syncytia formation and infection in a variety of cell lines and primary cells isolated from human ACE2 knock-in mice. The requirement for S2' cleavage at the R815 site was also broadly shared by other SARS-CoV-2 spike variants, such as the Alpha, Beta, and Delta variants of concern. Thus, our study highlights an essential role for host receptor engagement and the key residue of spike for proteolytic activation, and uncovers a targetable mechanism for host cell infection by SARS-CoV-2.

High sensitivity temperature sensor based on a side-hole fiber.

This paper proposes a temperature sensor based on a side-hole fiber (SHF). The sensor is formed by single-mode fiber (SMF)-coreless fiber (CLF)-SHF-CLF-SMF fusion splicing. The SHF adopts the dislocation fusion splicing method to ensure that one air hole is exposed. Two different interferences form a superposition, making the response more sensitive. The experiment shows that the sensitivity during heating and cooling is 1.587 nm/°C and 1.681 nm/°C, respectively, in the temperature range of 25-45°C. The sensor has high temperature sensitivity, exhibits easy processing, is smaller in size, and has important research value for temperature monitoring in daily life and industrial production.

Aim2 Couples With Ube2i for Sumoylation-Mediated Repression of Interferon Signatures in Systemic Lupus Erythematosus.

OBJECTIVE: Systemic lupus erythematosus (SLE) involves kidney damage, and the inflammasome-caspase-1 axis has been demonstrated to promote renal pathogenesis. The present study was designed to explore the function of the Absent in Melanoma 2 (Aim2) protein in SLE. METHODS: Female wild-type Aim2-/- , Aim2-/- Ifnar1-/- , Aim2-/- Rag1-/- , and Asc-/- mice ages 8-10 weeks received 1 intraperitoneal injection of 500 µl pristane or saline, and survival of mice was monitored twice a week for 6 months. RESULTS: The absence of Aim2, but not Asc, led to enhanced SLE in mice that received pristane treatment. Increased immune cell infiltration and type I interferon (IFN) signatures in the kidneys of Aim2-/- mice coincided with severity of lupus, which was alleviated by blockade of Ifnar1-mediated signal. Adaptive immune cells were also involved in the glomerular lesions of Aim2-/- mice after pristane challenge. Importantly, even in the absence of pristane, plasmacytoid dendritic cells in the kidneys of Aim2-/- mice were significantly increased compared to control animals. Accordingly, transcriptome analysis revealed that Aim2 deficiency led to enhanced expression of type I IFN-induced genes in the kidneys even at an early developmental stage. Mechanistically, Aim2 bound ubiquitin-conjugating enzyme 2i (Ube2i), which mediates sumoylation-based suppression of type I IFN expression deficiency of Aim2 decreased cellular sumoylation, resulting in an augmented type I IFN signature and kidney pathogenesis. CONCLUSION: The present study demonstrates a critical role for Aim2 in an optimal Ube2i-mediated sumoylation-based suppression of type I IFN generation and development of SLE. As such, the Aim2-Ube2i axis can thus be a novel target for intervention in SLE.

Driving Force and Optical Signatures of Bipolaron Formation in Chemically Doped Conjugated Polymers.

Molecular dopants are often added to semiconducting polymers to improve electrical conductivity. However, the use of such dopants does not always produce mobile charge carriers. In this work, ultrafast spectroscopy is used to explore the nature of the carriers created following doping of conjugated push-pull polymers with both F4 TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) and FeCl3 . It is shown that for one particular push-pull material, the charge carriers created by doping are entirely non-conductive bipolarons and not single polarons, and that transient absorption spectroscopy following excitation in the infrared can readily distinguish the two types of charge carriers. Based on density functional theory calculations and experiments on multiple push-pull conjugated polymers, it is argued that the size of the donor push units determines the relative stabilities of polarons and bipolarons, with larger donor units stabilizing the bipolarons by providing more area for two charges to co-reside.

The complete mitochondrial genome of Amphinemura claviloba (Wu, 1973) (Plecoptera: Nemouridae).

We sequenced the complete mitochondrial genome (mitogenome) of a stonefly, Amphinemura claviloba (Wu, 1973), of the family Nemouridae (Insecta: Plecoptera). The mitogenome was 15,707 bp long and contained typical 37 genes with an A+T content of 68.5%. All protein-coding genes (PCGs) use standard initiation codons (methionine and isoleucine), except ND1 and ND5 which starts with TTG and GTG, respectively. Two of the 13 PCGs harbor the incomplete termination codon. All tRNA genes have typical clover secondary structures, except the dihydrouridine (DHU) arm of tRNASer(AGN) forms a simple loop. Secondary structure models of the ribosomal RNA genes of A. claviloba are similar to those proposed for other insects. We also found some structural elements in the control region, such as tandem repeats, poly-C stretch and microsatellite-like elements, etc. Phylogenetic analyses showed the clades for the Nemoura, Amphinemura, and (Mesonemoura + Sphaeronemoura + Indonemoura + Protonemura) are well supported in a polytomy.

Examination of the relationship between viscoelastic properties and the invasion of ovarian cancer cells by atomic force microscopy.

The mechanical properties of cells could serve as an indicator for disease progression and early cancer diagnosis. This study utilized atomic force microscopy (AFM) to measure the viscoelastic properties of ovarian cancer cells and then examined the association with the invasion of ovarian cancer at the level of living single cells. Elasticity and viscosity of the ovarian cancer cells OVCAR-3 and HO-8910 are significantly lower than those of the human ovarian surface epithelial cell (HOSEpiC) control. Further examination found a dramatic increase of migration/invasion and an obvious decease of microfilament density in OVCAR-3 and HO-8910 cells. Also, there was a significant relationship between viscoelastic and biological properties among these cells. In addition, the elasticity was significantly increased in OVCAR-3 and HO-8910 cells after the treatment with the anticancer compound echinomycin (Ech), while no obvious change was found in HOSEpiC cells after Ech treatment. Interestingly, Ech seemed to have no effect on the viscosity of the cells. Ech significantly inhibited the migration/invasion and significantly increased the microfilament density in OVCAR-3 and HO-8910 cells, which was significantly related with the elasticity of the cells. An increase of elasticity and a decrease of invasion were found in OVCAR-3 and HO-8910 cells after Ech treatment. Together, this study clearly demonstrated the association of viscoelastic properties with the invasion of ovarian cancer cells and shed a light on the biomechanical changes for early diagnosis of tumor transformation and progression at single-cell level.

The complete mitochondrial genome of a stonefly species, Suwallia bimaculata (Plecoptera: Chloroperlidae).

The stonefly Suwallia bimaculata belongs to the Chloroperlidae. The mitogenome of S. bimaculata was sequenced and annotated, the new representative of the complete mitogenome of the genus Suwallia. The entire genome of S. bimaculata is 16,125 bp totally with an A + T content of 68.5%, consisting of 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and a 1,210 bp control region. All genes have the similar locations and strands with that of other published species of Plecoptera. Most PCGs use typical start/stop codon, whereas ND5 use GTG as start codon. And, COII and ND5 stopped with incomplete terminaton signal T. Phylogenetic analysis was performed using the Bayesian (BI) method and Maximum-likelihood (ML) methods based on 13 protein-coding genes and two ribosomal RNAs showed that S. bimaculata was the sister group to Suwallia teleckojensis and the clade Suwallia was closely to four perlodid species. More chloroperlid data was needed for further study of phylogeny in Chloroperlidae.

The complete mitochondrial genome of a stonefly species, Indonemoura auriformis (Plecoptera: Nemouridae).

One new mitochondrial genome of Indonemoura auriformis from the family Nemouridae (Insecta: Plecoptera) was sequenced in the study. The mitochondrial genome has the length of 15,718 bp, encoding 37 genes: 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, and 2 ribosomal RNA (rRNA) genes. The whole nucleotide composition biased adenine and thymine with A + T accounting for 69.9%. Nine PCGs and 14 tRNA genes are encoded in the J chain, the other four PCGs, eight tRNAs, and two rRNA genes are encoded in the chain of N. The mitochondrial genome includes 13 gene overlaps and 12 intergenic spacers. Most PCGs strictly use the ATN as start codon, and terminate with traditional stop codon (TAA and TAG). Except the tRNASer(AGN) seems to lack dihydrogen glycine arm, all tRNA genes of the mitochondrial genome are the typical clover secondary structure. The phylogenetic tree of PCGs dataset based on bayesian inference (BI) and maximum likelihood (ML) analysis show the same tree topology. Both ML and BI analysis support the sister-group relationship between Amphinemuria and Nemoura. Meanwhile, Capniidae is closely related to Taeniopterygidae.

The mitochondrial genome from the stonefly: Claassenia sp. (Plecoptera: Perlidae).

Claasseniini is the apparent sister group to all the other groups of Perlidae, and the small tribe Claasseniini has only one genus includes 12 species in the world. Only five mitochondrial genomes in the Perlinae have previously been reported. In this study, we sequenced the mitochondrial genome of Claassenia sp. Wu in genus Claassenia for the first time. The total length of the mitochondrial genome is 15,774 bp, and the DNA base composition is 34.0% A, 27.4% T, 25.6% C and 13.0% G. The whole genome contains 37 genes and one control region, which is similar to other published stoneflies. All PCG started with ATN except CCG for COI gene, TTG for ND1 gene, GTG for ND4 and ND5 genes. The termination codon of 11 PCGs used the normal complete codon TAA or TAG, and the COII and ND5 genes were terminated by a single T. All tRNAs except tRNASer(AGN) fold into a classic clover structure. The phylogenetic tree by Maximum likelihood (ML) and Bayesian (BI) methods supported that Claassenia sp. was the basal taxa of the Perlidae clade. This study provides new data for further mitochondrial genome study on the Perlidae.

The complete mitochondrial genome analysis of the stonefly, Flavoperla sp. (Plecoptera: Perlidae).

Flavoperla is a small genus in Acroneuriinae, which was established by Chu but was treated as a synonym for a long time until Uchida and Harper recognized Flavoperla as a valid genus. This genus includes 15 species in the world now, including six species from China. Here, we sequenced and annotated the mitochondrial genome of Flavoperla sp. under the next-generation sequence technology, the first representative of Genus Flavoperla. The complete mitochondrial genome of Flavoperla sp. is 15,796 bp in length with an A + T content of 68.3% showed a positive AT-skew (0.037) and a negative GC-skew (-0.262). The gene order and organization of the mitochondrial genome is consistent with other stoneflies. The control region had the highest A + T content. Eleven PCGs started with the typical codon (ATN), the remaining PCGs started with TTG (ND1and ND5). All PCGs terminated with TAA/TAG, except COII and ND5 used single T. The phylogenetic tree by maximum likelihood (ML) and Bayesian (BI) methods supported that Flavoperla sp. was the sister group to Niponiella limbatella.

FGF2 Attenuates Neural Cell Death via Suppressing Autophagy after Rat Mild Traumatic Brain Injury.

Traumatic brain injury (TBI) can lead to physical and cognitive deficits, which are caused by the secondary injury process. Effective pharmacotherapies for TBI patients are still lacking. Fibroblast growth factor-2 (FGF2) is an important neurotrophic factor that can stimulate neurogenesis and angiogenesis and has been shown to have neuroprotective effects after brain insults. Previous studies indicated that FGF2's neuroprotective effects might be related to its function of regulating autophagy. The present study investigated FGF2's beneficial effects in the early stage of rat mild TBI and the underlying mechanisms. One hundred and forty-four rats were used for creating controlled cortical impact (CCI) models to simulate the pathological damage after TBI. Our results indicated that pretreatment of FGF2 played a neuroprotective role in the early stage of rat mild TBI through alleviating brain edema, reducing neurological deficits, preventing tissue loss, and increasing the number of surviving neurons in injured cortex and the ipsilateral hippocampus. FGF2 could also protect cells from various forms of death such as apoptosis or necrosis through inhibition of autophagy. Finally, autophagy activator rapamycin could abolish the protective effects of FGF2. This study extended our understanding of FGF2's neuroprotective effects and shed lights on the pharmacological therapy after TBI.