The evolution and diversification of oakleaf butterflies.

Oakleaf butterflies in the genus Kallima have a polymorphic wing phenotype, enabling these insects to masquerade as dead leaves. This iconic example of protective resemblance provides an interesting evolutionary paradigm that can be employed to study biodiversity. We integrated multi-omic data analyses and functional validation to infer the evolutionary history of Kallima species and investigate the genetic basis of their variable leaf wing patterns. We find that Kallima butterflies diversified in the eastern Himalayas and dispersed to East and Southeast Asia. Moreover, we find that leaf wing polymorphism is controlled by the wing patterning gene cortex, which has been maintained in Kallima by long-term balancing selection. Our results provide macroevolutionary and microevolutionary insights into a model species originating from a mountain ecosystem.

Multiple Origins of Bioluminescence in Beetles and Evolution of Luciferase Function.

Bioluminescence in beetles has long fascinated biologists, with diverse applications in biotechnology. To date, however, our understanding of its evolutionary origin and functional variation mechanisms remains poor. To address these questions, we obtained high-quality reference genomes of luminous and nonluminous beetles in 6 Elateroidea families. We then reconstructed a robust phylogenetic relationship for all luminous families and related nonluminous families. Comparative genomic analyses and biochemical functional experiments suggested that gene evolution within Elateroidea played a crucial role in the origin of bioluminescence, with multiple parallel origins observed in the luminous beetle families. While most luciferase-like proteins exhibited a conserved nonluminous amino acid pattern (TLA346 to 348) in the luciferin-binding sites, luciferases in the different luminous beetle families showed divergent luminous patterns at these sites (TSA/CCA/CSA/LVA). Comparisons of the structural and enzymatic properties of ancestral, extant, and site-directed mutant luciferases further reinforced the important role of these sites in the trade-off between acyl-CoA synthetase and luciferase activities. Furthermore, the evolution of bioluminescent color demonstrated a tendency toward hypsochromic shifts and variations among the luminous families. Taken together, our results revealed multiple parallel origins of bioluminescence and functional divergence within the beetle bioluminescent system.

Mitochondrial Ca2+ Uniporter Is a Mitochondrial Luminal Redox Sensor that Augments MCU Channel Activity.

Ca2+ dynamics and oxidative signaling are fundamental mechanisms for mitochondrial bioenergetics and cell function. The MCU complex is the major pathway by which these signals are integrated in mitochondria. Whether and how these coactive elements interact with MCU have not been established. As an approach toward understanding the regulation of MCU channel by oxidative milieu, we adapted inflammatory and hypoxia models. We identified the conserved cysteine 97 (Cys-97) to be the only reactive thiol in human MCU that undergoes S-glutathionylation. Furthermore, biochemical, structural, and superresolution imaging analysis revealed that MCU oxidation promotes MCU higher order oligomer formation. Both oxidation and mutation of MCU Cys-97 exhibited persistent MCU channel activity with higher [Ca2+]m uptake rate, elevated mROS, and enhanced [Ca2+]m overload-induced cell death. In contrast, these effects were largely independent of MCU interaction with its regulators. These findings reveal a distinct functional role for Cys-97 in ROS sensing and regulation of MCU activity.

Cloning and characterization of luciferase from an Asian firefly Pygoluciola qingyu and its comparison with other beetle luciferases.

The bioluminescence system of luminescent beetles has extensive applications in biological imaging, protein labeling and drug screening. To explore wild luciferases with excellent catalytic activity and thermal stability, we cloned the luciferase of Pygoluciola qingyu, one species living in areas of high temperature and with strong bioluminescence, by combining transcriptomic sequencing and reverse transcription polymerase chain reaction (RT-PCR). The total length of luciferase gene is 1638 bp and the luciferase consists 544 amino acids. The recombinant P. qingyu luciferase was produced in vitro and its characteristics were compared with those of eight luciferases from China firefly species and two commercial luciferases. Compared with these luciferases, the P. qingyu luciferase shows the highest luminescence activity at room temperature (about 25-28 â„ƒ) with similar KM value for D-luciferin and ATP to the Photinus pyralis luciferase. The P. qingyu luciferase activity was highest at 35 â„ƒ and can keep high activity at 30-40 â„ƒ, which suggests the potential of P. qingyu luciferase for in vivo and cell application. Our results provide new insights into P. qingyu luciferase and give a new resource for the application of luciferases.

RNAi efficiency is enhanced through knockdown of double-stranded RNA-degrading enzymes in butterfly Papilio xuthus.

The efficiency of RNA interference (RNAi) has always limited the research on the phenotype innovation of Lepidoptera insects. Previous studies have found that double-stranded RNA-degrading enzyme (dsRNase) is an important factor in RNAi efficiency, but there have been no relevant reports in butterflies (Papilionoidea). Papilio xuthus is one of the important models in butterflies with an extensive experimental application value. To explore the effect of dsRNase in the RNAi efficiency on butterflies, six dsRNase genes (PxdsRNase 1-6) were identified in P. xuthus genome, and their dsRNA-degrading activities were subsequently detected by ex vivo assays. The result shows that the dsRNA-degrading ability of gut content (<1 h) was higher than hemolymph content (>12 h). We then investigated the expression patterns of these PxdsRNase genes during different tissues and developmental stages, and related RNAi experiments were carried out. Our results show that different PxdsRNase genes had different expression levels at different developmental stages and tissues. The expression of PxdsRNase2, PxdsRNase3, and PxdsRNase6 were upregulated significantly through dsGFP injection, and PxdsRNase genes can be silenced effectively by injecting their corresponding dsRNA. RNAi-of-RNAi studies with PxEbony, which acts as a reporter gene, observed that silencing PxdsRNase genes can increase RNAi efficiency significantly. These results confirm that silencing dsRNase genes can improve RNAi efficiency in P. xuthus significantly, providing a reference for the functional study of insects such as butterflies with low RNAi efficiency.

TRIM16 exerts protective function on myocardial ischemia/reperfusion injury through reducing pyroptosis and inflammation via NLRP3 signaling.

Myocardial infarction is still a leading cause of morbidity and mortality worldwide, but its pathogenesis has not been fully understood. In the study, we attempted to explore the effects of E3 ligase tripartite motif 16 (TRIM16) on myocardial ischemia-reperfusion (MI/R) injury in vivo and in vitro, and the underlying mechanisms. We identified that TRIM16 was indeed a potent regulator during MI/R progression in murine models and surprisingly showed a negative correlation with the concentrations of cardiac pro-inflammatory cytokines. Adenoviral vectors encoding GFP or TRIM16 (Ad-TRIM16) were subjected to mice through direct injection into the left ventricular (LV). We found that Ad-TRIM16 significantly reduced the infarct size, and improved the cardiac function and structure compared with the Ad-GFP mice after MI/R operation. More studies indicated that TRIM16 over-expression strongly meliorated nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and associated inflammatory response in hearts of MI/R-induced mice, which were validated in hypoxia/reoxygenation (H/R)-exposed primary cardiomyocytes in vitro. In particular, MI/R operation led to cardiac pyroptosis by increasing the cleavage of Caspase-1 and Gasdermin D (GSDMD), while being considerably abrogated upon TRIM16 over-expression. Mechanistically, TRIM16 interacted with NLRP3 and promoted the K48-linked polyubiquitination of NLRP3, ultimately promoted its degradation. Together, we identified TRIM16 as a novel E3 ubiquitin ligase for NLRP3, which played an essential role in modulating its expression, and subsequently influenced inflammatory response and pyroptosis in MI/R murine model, confirming that TRIM16 may be a potential therapeutic target for myocardial infarction.

Complete mitochondrial genome of Pectocera sp. (Elateridae: Dendrometrinae: Oxynopterini) and its phylogenetic implications.

The Elateridae family (click beetles) represents a highly diverse lineage that possesses a specialized clicking mechanism to startle predators. At present, however, phylogenetic relationships, especially among recognized subfamilies, remain contentious. Mitochondrial genomes (mitogenomes) can help resolve previously intractable phylogenetic relationships using morphological or limited molecular data. Here, we report the complete mitogenome of Pectocera sp. (Elateridae: Dendrometrinae: Oxynopterini), which was 15,962 bp in length and showed a typical gene number and order as most beetle mitogenomes, including 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 noncoding control region (AT-rich region). Comparative genomic analyses showed a high degree of feature similarity among Pectocera sp. and other click beetles. Evolutionary analysis of all PCGs based on the nonsynonymous/synonymous substitution rate ratio (ω) indicated that cox1 and atp8 exhibited the lowest and highest evolutionary rates, respectively, and that the evolutionary rates of all PCGs, except for cox3, nad2, and nad3, were lower than the average ω of click beetles. Phylogenetic analyses based on concatenated and coalescent approaches indicated that Pectocera sp. was sister to Campsosternus auratus in the same tribe (Oxynopterini) with high support. This study offers insight into the mitogenomic basis of Pectocera sp. and provides an important data resource for exploring the taxonomy, phylogeny, and evolution of click beetles.

Genome-wide survey of open chromatin regions in two swallowtail butterflies Papilio machaon and P. bianor.

Papilio machaon was assigned as the type species for all butterflies by Linnaeus and P. bianor is a congener but exhibits a great difference in morphology (especially larva and adult color pattern) and larval host plants from P. machaon. Thus, they are the ideal models to investigate genetic mechanisms underlying morphology and plasticity between congeners. The reference genomes of both species were dissected in our previous studies, but little is known about their regulatory genome and the epigenetic regulation of gene expression throughout developmental stages. Here, we profiled the chromatin accessibility and gene expression of three developmental stages (the 4th instar larva [L4], the 5th instar larva [L5], and pupa [P]) using transposase accessible chromatin sequencing (ATAC-seq) and RNA-seq. Results showed that many accessible chromatin peaks were identified at three developmental stages (peak number, P. machaon: 44,977 [L4], 36,919 [L5], 47,147 [P]; P. bianor: 20,341 [L4], 44,668 [L5], 62,249 [P]). Moreover, the number of differentially accessible peaks and differentially expressed genes between larval stages of each butterfly species are significantly fewer than that between larval and pupal stages, suggesting a higher similarity within larvae and a significant difference between larvae and pupae. This study added the annotated information of chromatin accessibility genome-wide of the two papilionid species and will promote the investigation of gene regulation in butterfly evolution.

Experimental investigation of flow-focusing-assisted magnetorheological jet polishing.

To improve the stability of magnetorheological jet polishing (MJP), a processing method of flow-focusing-assisted MJP is proposed in this paper. A relevant experimental setup was developed based on this method. The effects of the parameters (gas pressure drop, diameter of the small hole, and focusing distance) in the flow-focusing technique on the jet stability were studied by computational fluid dynamics simulation and experiment. The results show that the optimal gas pressure range is from 0.6 to 0.7 times the jet pressure, the optimal diameter of the small hole range is from 2.1 to 2.3 times the nozzle diameter, and the optimal focusing distance range is from 3.5 to 4.5 times the nozzle diameter. This is a preliminary attempt to provide a reference for future experimental studies of flow-focusing-assisted MJP.

Building roof extraction from ASTIL echo images applying OSA-YOLOv5s.

Light detection and ranging (LiDAR) is a type of essential tool for urban planning and geoinformation extraction. Airborne streak tube imaging LiDAR (ASTIL) is a new system with great advantages in the rapid collection of remote sensing data. To the best of our knowledge, a new method to extract a building roof from the echo images of ASTIL is proposed. We improve YOLOv5s with a one-shot aggregation (OSA) module to improve efficiency. The experimental results show that the mean average precision of the OSA-YOLOv5s algorithm can reach 95.2%, and the frames per second can reach 11.74 using a CPU and 39.39 using a GPU. The method proposed can extract building objects efficiently from the echo images of ASTIL and acquire the building roof point cloud.

Effectiveness of one-time endoscopic screening programme in prevention of upper gastrointestinal cancer in China: a multicentre population-based cohort study.

OBJECTIVES: To estimate the effectiveness of endoscopic screening programme in reducing incidence and mortality of upper gastrointestinal cancer in high risks areas of China. DESIGN: This multicentre population-based cohort study was conducted in six areas in China from 2005 to 2015. All permanent residents aged 40 to 69 years were identified as target subjects. We refer to those who were invited for screening collectively as the invited group. Of these, we classify those who were invited and undertook endoscopic screening as the screened group and those who were invited but did not accept screening as the non-screened group. Target subjects who were not invited to the screening were assigned to the control group. The effectiveness of the endoscopic screening and screening programme were evaluated by comparing reductions in incidence and mortality from upper gastrointestinal cancer in the screened and invited group with control group. RESULTS: Our cohort analysis included 637 500 people: 299 483 in the control group and 338 017 in the invited to screening group, 113 340 (33.53%) of whom were screened eventually. Compared with subjects in the control group, upper gastrointestinal cancer incidence and mortality decreased by 23% (relative risk (RR)=0.77, 95% CI 0.74 to 0.81) and 57% (RR=0.43, 95% CI 0.40 to 0.47) in the screened group, respectively, and by 14% (RR=0.86, 95% CI 0.84 to 0.89) and 31% (RR=0.69, 95% CI 0.66 to 0.72) in the invited group, respectively. CONCLUSION: Among individuals aged 40 to 69 years in high risk areas of upper gastrointestinal cancer, one-time endoscopic screening programme was associated with a significant decrease in upper gastrointestinal cancer incidence and mortality.

Genome-wide identification and gene-editing of pigment transporter genes in the swallowtail butterfly Papilio xuthus.

BACKGROUND: Insect body coloration often functions as camouflage to survive from predators or mate selection. Transportation of pigment precursors or related metabolites from cytoplasm to subcellular pigment granules is one of the key steps in insect pigmentation and usually executed via such transporter proteins as the ATP-binding cassette (ABC) transmembrane transporters and small G-proteins (e.g. Rab protein). However, little is known about the copy numbers of pigment transporter genes in the butterfly genomes and about the roles of pigment transporters in the development of swallowtail butterflies. RESULTS: Here, we have identified 56 ABC transporters and 58 Rab members in the genome of swallowtail butterfly Papilio xuthus. This is the first case of genome-wide gene copy number identification of ABC transporters in swallowtail butterflies and Rab family in lepidopteran insects. Aiming to investigate the contribution of the five genes which are orthologous to well-studied pigment transporters (ABCG: white, scarlet, brown and ok; Rab: lightoid) of fruit fly or silkworm during the development of swallowtail butterflies, we performed CRISPR/Cas9 gene-editing of these genes using P. xuthus as a model and sequenced the transcriptomes of their morphological mutants. Our results indicate that the disruption of each gene produced mutated phenotypes in the colors of larvae (cuticle, testis) and/or adult eyes in G0 individuals but have no effect on wing color. The transcriptomic data demonstrated that mutations induced by CRISPR/Cas9 can lead to the accumulation of abnormal transcripts and the decrease or dosage compensation of normal transcripts at gene expression level. Comparative transcriptomes revealed 606 ~ 772 differentially expressed genes (DEGs) in the mutants of four ABCG transporters and 1443 DEGs in the mutants of lightoid. GO and KEGG enrichment analysis showed that DEGs in ABCG transporter mutants enriched to the oxidoreductase activity, heme binding, iron ion binding process possibly related to the color display, and DEGs in lightoid mutants are enriched in glycoprotein binding and protein kinases. CONCLUSIONS: Our data indicated these transporter proteins play an important role in body color of P. xuthus. Our study provides new insights into the function of ABC transporters and small G-proteins in the morphological development of butterflies.

Molecular cloning, characterization, and evolution analysis of the luciferase genes from three sympatric sibling fireflies (Lampyridae: Lampyrinae, Diaphanes).

Firefly adult bioluminescence functions as signal communication between sexes. How sympatric sibling species with similar glow pattern recognize their conspecific mates remains largely unknown. To better understand the role of the luciferases of sympatric fireflies in recognizing mates, we cloned the luciferase genes of three sympatric forest dwelling fireflies (Diaphanes nubilus, Diaphanes pectinealis, and Diaphanes sp2) and evaluated their enzyme characteristics. Our data show that the amino acid (AA) sequences of all three luciferases are highly conserved, including the identities (D. nubilus vs D. pectinealis: 99%; D. nubilus vs Diaphanes sp2: 98.5%; D. pectinealis vs Diaphanes sp2: 99.4%) and the protein structures. Three recombinant luciferases produced in vitro all possess significant luminescence activity at pH 7.8, and similar maximum emission spectrum (D. nubilus: 562 nm; D. pectinealis and Diaphanes sp2: 564 nm). They show the highest activity at 10 °C (D. pectinealis, Diaphanes sp2) and 15 °C (D. nubilus), and completely inactivation at 45 °C. Their KM for D-luciferin and ATP were 2.7 µM and 92 µM (D. nubilus), 3.7 µM and 49 µM (D. pectinealis), 3.5 µM and 46 µM (Diaphanes sp2). Phylogenetic analyses support that D. nubilus is sister to D. pectinealis with Diaphanes sp2 at their base, which further cluster with Pyrocoelia. All combined data indicate that sympatric Diaphanes species have similar luciferase characteristics, suggesting that other strategies (e.g., pheromone, active time, etc.) may be adopted to recognize mates. Our data provide new insights into Diaphanes luciferases and their evolution.

Voxel-based spatial elongation filtering method for airborne single-photon LiDAR data.

A novel voxel-based spatial elongation filtering method is proposed, to reduce noise in airborne single-photon lidar (SPL) data. In this method, six additional points are generated adjacent to each point of interest in the SPL data. Then, we count the number of points within each voxel and discriminate signals from noise via a predefined threshold. A filter performance evaluation index (taking into account the false alarm and signal loss rates, and the average distance between the residual noise points and their nearest signal points) is introduced. We compare the proposed and voxel-based spatial filtering method. The average false alarm rate found with our method (3.5%) is 18.6% smaller than that of the voxel-based spatial filtering method (4.3%).

Phylogenetic analysis provides insights into the evolution of Asian fireflies and adult bioluminescence.

Fireflies are one of the best-known examples of luminescent organisms. The limited geographic distribution and rarity of some firefly genera have hindered molecular phylogenetic analysis, resulting in uncertainty in regard to firefly phylogeny. Here, using genome skimming next-generation sequencing, we sequenced 23 Asian firefly species from 15 genera (Lampyridae: 14; Rhagophthalmidae: one) and assembled their mitochondrial genomes (mitogenomes) and nuclear ribosomal DNA (rDNA) repeat unit. The mitogenomes (including 15 mitochondrial genes: COX1-3, ATP6&8, ND1-6&4L, CYTB, 12S, and 16S) were recovered for almost all 23 species; furthermore, three regions of the nuclear rDNA repeat unit (18S, 28S, and 5.8S) were recovered for 22 out of the 23 species. The mitogenomes of 11 genera and 22 species as well as the complete rDNA from 22 species are reported here for the first time. Combined with previously published sequences of mitochondrial and rDNA coding regions, 166 species (170 populations with four overlapping in Lampyridae) were included in the current analyses. We selected different species groups and coding regions to infer phylogenies, and then employed tree certainty (TC) and internode certainty (IC) to quantify any phylogenetic incongruence. Phylogenetic analysis of 18 coding regions (15 mitochondrial genes and three regions of the nuclear rDNA repeat unit) from different species groups showed that the 144-species selection group (excluding 22 species outside Lampyridae) had relatively high TC (101.39). Further phylogenetic analysis of the 144 species using different coding regions indicated that the phylogeny of the 13 coding regions (10 mitochondrial genes: COX1-2, ATP6&8, ND1, ND4-5, CYTB, 12S and 16S; three rDNA regions: 18S, 5.8S, and 28S) demonstrated higher TC (103.02) than the phylogenies based on the 18 coding regions (TC = 101.39), conserved-regions (c-regions, i.e., 12S, 16S, COX1, 18S, and 28S) (TC = 95.11), or conserved-sites (c-sites, TC = 92.31) for the mitochondrial genes. In contrast, the c-sites strengthened the deeper nodes of the 144-species phylogeny compared to the c-regions. All of the 144-species phylogenies using different coding regions (except the c-regions) consistently recovered the monophyly of each of the three luminous families and their combination (Lampyridae, Rhagophthalmidae, and Phengodidae) with high IC support. Our phylogenetic analyses clarified the position of firefly genera Lamprigera, Vesta, Stenocladius, Pyrocoelia, Diaphanes, Abscondita, Pygoluciola, Emeia, Pristolycus, and Menghuoius. We also inferred the evolutionary pattern of adult bioluminescence in Lampyridae based on the phylogenies of 166 and 144 species. Our data suggest that the common ancestor of Lampyridae possessed adult bioluminescence, with a higher loss rate than gain rate of bioluminescence during its lineage evolution. Our results provide insight into Asian firefly phylogeny, and also enrich mitogenome and rDNA data resources for further study.

Astragaloside-IV Protects Against Heat-induced Apoptosis by Inhibiting Excessive Activation of Mitochondrial Ca2+ Uniporter.

BACKGROUND: Heat causes airway damage during inhalation injury because of bronchial epithelial cell damage. Accumulating evidence shows that mitochondrial uniporter (MCU) is involved in cell damage. We investigated the MCU activity after heat treatment and assessed whether Astragaloside-IV (AS-IV) suppresses heat-induced apoptosis in bronchial epithelial cells by inhibiting the activation of the mitochondrial Ca2+ uniporter (MCU), mitochondrial depolarisation and reactive oxygen species (ROS) production. METHODS: The bronchial epithelial cell line 16HBE14o- was heat treated, and cell apoptosis was induced in vitro and in vivo. AS-IV was inorganically administered to Wistar rats twice a day after thermal inhalation injury, and 16HBE140- cells were treated with AS-IV after incubation at 47°C for 5 min. Protein expression was determined using Western blotting and commercial kits, apoptosis with TUNEL staining, mitochondrial channel activity by patch clamp, reactive oxygen species by MitoSOXTM fluorescence, ATP levels and enzyme activities by commercial kits as well as mitochondrial respiration and calcium by fluorescence. RESULTS: AS-IV markedly inhibited heat-induced apoptosis, as indicated by the increased expression of the pro-apoptotic genes Bak, Bik and Bmf and increased expression of the apoptosis markers Bax, cleaved parp, cleaved caspase3 and cytochrome C. We found that MCU activation promoted mitochondrial Ca2+ overload, ATP depletion, mitochondrial ROS production and cytochrome c release and rapidly induced apoptosis. However, AS-IV treatment reduced excessive MCU activation and led to resistance against mitochondrial Ca2+ overload and excessive cytochrome C release; these effects were blocked by the MCU activator spermine. AS-IV treatment elevated ATP production and decreased ROS activity. CONCLUSIONS: MCU plays crucial roles in heat-induced mitochondrial apoptosis in 16HBE140- cells, suggesting a potential target for AS-IV treatment.

Stachydrine Protects Against Pressure Overload-Induced Cardiac Hypertrophy by Suppressing Autophagy.

BACKGROUND: Autophagy is required for the maintenance of cardiomyocyte homeostasis. However, excessive autophagy plays a maladaptive role in pressure overload-induced heart failure. To identify mechanisms by which Stachydrine inhibits pressure overload-induced cardiac hypertrophy, we determined inhibitory activities against activation of NADPH oxidase, reactive oxygen species(ROS) production and excessive activation of autophagy. METHODS: Stachydrine was administered intragastrically to Wistar rats after Transverse aortic constriction(TAC) and H9c2 cells were treated with Stachydrine after Angiotension II stimulation. The activation of NADPH oxidase2 required the membrane translocation of p47phox and p67phox. Cell membrane fraction was isolated by ultracentrifuge in sucrose. The expression of p67phox, p47phox, gp91phox subunit in the cell membrane were determined by western blot. The combination of p67phox and gp91 phox subunit was detected by immunofluorescence staining. The expression of phosphorylated p47phox subunit was determined by western blot. The intracellular ROS were measured with DCF-DA fluoresence. The autophagic flux was measured by recording the fluorescence emission of the fusion protein mRFP-GFP-LC3 by dynamic live-cell imaging. Reuslts: We report here that stachydrine, a major constituent of Leonurus heterophyllus Sweet, inhibited AngII-induced excessive autophagy within H9c2 cells. Stachydrine blocked the over phosphorylation of the p47phox subunit, decreased the translocation of p47phox and p67phox to the membrane, inhibited the activity of NOX2, and reduced the generation of ROS. We also demonstrated that stachydrine ameliorated TAC-induced cardiac hypertrophy, dysfunction and excessive autophagy in vivo. CONCLUSIONS: Our study highlights the importance of regulating NOX2 when autophagy is obviously activated. By inhibiting NOX2, Stachydrine inhibits ROS production, thus exerting a remarkable activity of inhibiting hypertrophy, which could have considerable effect on clinical practice.

Phage Abp1 Rescues Human Cells and Mice from Infection by Pan-Drug Resistant Acinetobacter Baumannii.

BACKGROUND/AIMS: As an "ESKAPE" pathogen, Acinetobacter baumannii is one of the leading causes of drug-resistant infections in humans. Phage therapy may be a useful strategy in treating infections caused by drug-resistant A. baumannii. Among 21 phage strains that were isolated and described earlier, we investigated the therapeutic efficacy of Abp1 because of its relatively wide host range. METHODS: Phage stability assays were used to evaluate thermal and pH stability of Abp1. Abp1 was co-cultured with A. baumannii (AB1) over a range of multiplicities of infection to determine its bactericidal efficacy. HeLa or THP-1 cells were used in the cytotoxicity and protection assays. Finally, the therapeutic effects of Abp1 on local and systemic A. baumannii infection in mice were determined. RESULTS: We found that Abp1 exhibits high thermal and pH stability and has a low frequency of lysogeny. Bacteriophage resistance also occurs at a very low frequency (3.51±0.46×10-8), and Abp1 can lyse almost all host cells at a MOI as low as 0.1. Abp1 has no detectable cytotoxicity to HeLa or THP-1 cells as determined by LDH release assay. Abp1 can rescue HeLa cells from A. baumannii infection, even if introduced 2 hours post infection. In both local and systemic A. baumannii infection mouse models, Abp1 treatment exhibits good therapeutic effects. CONCLUSION: Abp1 is an excellent candidate for phage therapy against drug-resistant A. baumannii infections.

Concurrent CCR7 Overexpression and RelB Knockdown in Immature Dendritic Cells Induces Immune Tolerance and Improves Skin-Graft Survival in a Murine Model.

BACKGROUND/AIMS: Skin transplantation aims to cover skin defects but often fails due to immune rejection of the transplantated tissue. Immature dendritic cells (imDCs) induce immune tolerance but have a low migration rate. After stimulation, imDCs transform into mature DCs, which activate immune rejection. Thus, inducing imDC to obtain a high migration counteracts development of immune tolerance. METHODS & RESULTS: We transfected imDCs with a recombinant adenovirus carrying the CCR7 gene (Ad-CCR7) and a small interfering RNA targeting RelB (RelB-siRNA) to concurrently overexpress CCR7 and downregulate RelB expression. Functionally, such cells showed a significantly enhanced migration rate in the chemotactic assay and decreased T-cell proliferation after lipopolysaccharide stimulation in mixed lymphocyte reactions. Cotransfected cells showed an increased ability to induce immune tolerance by upregulating T regulatory (Treg) cells and shifting the Th1/Th2 ratio. Cotransfection of Ad-CCR7 and RelB-siRNA endowed imDCs with resistance to apoptosis and cell death. CCR7 overexpression and RelB knockdown (KD) in imDCs improve skin-graft survival in a murine skin-transplantation model. CONCLUSION: Transfection with Ad-CCR7 and RelB KD in imDCs may be an effective approach inducing immune tolerance, thus being potentially valuable for inhibiting allograft rejection.

Astragaloside-IV Alleviates Heat-Induced Inflammation by Inhibiting Endoplasmic Reticulum Stress and Autophagy.

BACKGROUND: Thermal injury is the main cause of pulmonary disease in stroke after burn and can be life threatening. Heat-induced inflammation is an important factor that triggers a series of induces pathological changes. However, this mechanism underlying heat-induced inflammation in thermal inhalation injury remains unclear. Studies have revealed that astragaloside-IV (AS-IV), a natural compound extracted from Astragalus membranaceus, has protective effects in inflammatory diseases. Here, we investigated whether the protective effects of AS-IV occur because of the suppression of heat-induced endoplasmic reticulum (ER) stress and excessive autophagy Methods: AS-IV was administered to Wistar rats after thermal inhalation injury and 16HBE140-cells were treated with AS-IV. TNF-α, IL-6, and IL-8 levels were determined by ELISA and real-time PCR. ER stress and autophagy were determined by western blot. Autophagic flux was measured by recording the fluorescence emission of the fusion protein mRFP-GFP-LC3 by dynamic live-cell imaging. RESULTS: AS-IV had protective effects against heat-induced reactive oxygen species production and attenuated ER stress. AS IV alleviated heat-induced excessive autophagy in vitro and in vivo. Excessive autophagy was attenuated by the PERK inhibitor GSK2656157 and eIF2α siRNA, suggesting that heat stress-induced autophagy can activate the PERK-eIF2α pathway. Beclin 1 and Atg5 siRNAs inhibited the upregulation of the inflammatory cytokines TNF-α, IL-6, and IL-8 after heat exposure. CONCLUSIONS: Thus, AS-IV may attenuate inflammatory responses by disrupting the crosstalk between autophagy and the PERK-eIF2α pathway and may be an ideal agent for treating inflammatory pulmonary diseases.