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As a new type of biologically compatible material, TiO2 NPs are widely used in the industry as additives, drug carriers, and components of skin care products. Due to their wide use, residual TiO2 NPs in the environment are a safety concern that has attracted extensive attention. In this study, the ovarian cell line BmN of the model organism Bombyx mori was used to reveal the damaging effects of TiO2 NPs exposure. The results demonstrated that TiO2 NPs exhibited a dose-dependent effect on the relative cell viability, with significant toxic effects being observed above 20 mg/L. Oxidative damage analysis showed that ROS accumulated significantly in BmN cells after exposure to TiO2 NPs (P ≤ 0.05) and induced DNA damage. Further analysis revealed that the transcriptional levels of key superoxide dismutase genes (SOD) decreased significantly, while the transcriptions of key genes of the MAPK/NF-κB signaling pathway (P38, MEK, ERK and REL) and the downstream inflammatory factor genes (IL6 and TNFSF5) were all significantly up-regulated (P ≤ 0.05). Overall, our results indicate that exposure to TiO2 NPs leads to reduced transcription of antioxidant genes, accumulation of peroxides, and inflammation. These findings provide valuable data for the safety evaluation of environmental residues of TiO2 NPs.

Mitochondrial genomes (mitogenomes) have been widely used for studies on phylogenetic relationships and molecular evolutionary biology. Here, the complete mitogenome sequence of Spilosoma lubricipedum (Noctuoidea: Erebidae: Arctiinae) was determined (total length 15,375 bp) and phylogenetic analyses S. lubricipedum were inferred from available noctuid sequence data. The mitogenome of S. lubricipedum was found to be highly A + T-biased (81.39%) and exhibited negative AT- and GC-skews. All 13 protein-coding genes (PCGs) were initiated by ATN codons, except for cox1 with CGA. All tRNAs exhibited typical clover-leaf secondary structures, except for trnS1. The gene order of the S. lubricipedum mitogenome was trnM-trnI-trnQ-nad2. The A + T-rich region of S. lubricipedum contained several conservative features common to noctuid insects. Phylogenetic analysis within Noctuoidea was carried out based on mitochondrial data. Results showed that S. lubricipedum belonged to Erebidae and the Noctuoidea insects could be divided into five well-supported families (Notodontidae + (Erebidae + (Nolidae + (Euteliidae + Noctuidae)))).

Glioma is a type of malignant tumor arising from glial cells of the brain or the spine. Circulation-derived macrophage infiltration is a characteristic of the glioma microenvironment. The polarization status of circulation-derived macrophages in patients with glioma remains unclear. Therefore, the present study aimed to evaluate the polarization status of circulation-derived macrophages in patients with glioma. A total of 40 patients with glioma and 38 healthy volunteers were recruited. The polarization status of macrophage-like cells in the peripheral blood of patients with glioma was evaluated. In addition, the associations between the polarization status of macrophage-like cells and glioma stage or the expression levels of the glioma tumor marker chitinase-3-like protein 1 (also termed YKL-40) were evaluated. The number of macrophage-like cells (CD115(+)CD1c(−)CD2(−)CD15(−)CD19(−)CD14(+)CD16(+)CD11b(+)) was higher in the peripheral blood of patients with glioma compared with that of healthy volunteers. There were fewer M1 macrophage-like cells, and more M2 macrophage-like cells were induced in the peripheral blood of patients with glioma compared with healthy controls. Specifically, the number of M2a/M2b macrophage-like cells increased, whereas that of M2c macrophage-like cells decreased in the peripheral blood of patients with glioma compared with healthy controls. The polarization status of macrophage-like cells in patients with glioma was not significantly associated with glioma stage or with the glioma marker YKL-40. Overall, the results of the present study revealed that the polarization status of macrophage-like cells in the peripheral blood of patients with glioma was abnormal, offering potential novel diagnostic and therapeutic targets, such as different macrophage subsets, for glioma.

Silkworm (Bombyx mori) is an important economic insect. Bombyx mori, which is exposed to sublethal doses of pesticides, has a low or no mortality rate, while it is susceptible to infections triggered by foreign pathogens. The immune regulatory mechanism of silkworms caused by trace pesticides still remains unclear. The midgut is the major organ of silkworm for digestion and nutrient absorption, and it plays a critical defensive role against pathogens. In the present study, the silkworm was susceptible to Enterobacter cloacae sp. (E. cloacae) after exposure to sublethal dose of phoxim. The body weight and survival rate of the phoxim-E. cloacae co-treatment group were significantly decreased after 120 h of treatment compared with the phoxim treatment group. The immune responses and expressions of immune-related genes were dysregulated in the midgut of silkworm following exposure to phoxim. Digital gene expression (DGE) analysis revealed that 44 immune response-related and immune defense-related genes were differentially expressed. qRT-PCR results indicated that the transcriptional levels of antimicrobial peptide genes Bmdefensin1, BmcecA, Bmglv1, Bmglv2, Bmmoricin and BmmoricinB3 were down-regulated by 0.77-, 0.37-, 0.05-, 0.19-, 0.34- and 0.54-fold, respectively. The transcriptional levels of Toll signaling pathway genes Bmcactus, Bmspatzle and Bmrel were down-regulated by 0.4-, 0.37- and 0.96-fold, respectively. Peritrophic membrane (PM) protein-related genes BmCBP-02, BmPM-41, BmPM-43 and BmCDA7 were down-regulated by 0.18-, 0.02-, 0.66- and 0.16-fold, respectively. The expressions of Toll signaling pathway genes were down-regulated at 48 h and 72 h. Immune deficiency (IMD) and Janus kinase and signal transducer and activator of transcription (JAK/STAT) signaling pathway genes were dysregulated after phoxim exposure. These results indicated that phoxim might cause damage to the PM and reduce the immune response of the silkworm, leading to susceptibility of silkworm to disease and damage from foreign pathogens.

Global warming is known to affect the growth, development and reproduction of insects. In this study, the larvae developmental process and endogenous hormone levels under high temperature (36 °C) stress were investigated in the lepidopteran model insect Bombyx mori (B. mori). After high temperature treatment, the duration of 5th instar larvae was shortened by 28 ± 2 h, the content of 20-hydroxyecdysone(20E) in hemolymph was significantly increased, and the transcription levels of the 20E response genes E93, Br–C, USP and E75 were up-regulated by 1.35-, 1.25-, 1.28-, and 1.27-fold, respectively. High temperature treatment also elevated the phosphorylation level of Akt and activated the downstream BmCncC/keap1 pathway, and the transcription levels of the 20E synthesis-related genes cyp302a1, cyp306a1, cyp314a1 and cyp315a1 were up-regulated by 1.12-, 1.51-, 2.17- and 1.23-fold, respectively. The transcription levels of cyp302a1 and cyp306a1 were significantly decreased in BmN cells after treatment with the double stranded RNA of BmCncC (dsBmCncC), whereas their transcription levels were significantly increased (2.15- and 1.31-fold, respectively) after treatment with the CncC agonist Curcumin. These results demonstrated that high temperature treatment promoted the metamorphosis and the BmCncC/keap1 pathway played a role in the metamorphosis of B. mori. Our results provided clues for understanding the CncC/keap1 pathway-mediated regulation of metamorphosis of Lepidopteran insects.

Chlorantraniliprole (CAP) can induce excessive calcium release from muscle of insects, causing muscle paralysis until death, and its residues in farmland can cause poisoning in Bombyx mori (B. mori), resulting in the failure of cocooning. No reports have investigated the effects of CAP exposure on detoxification enzyme activities and detoxification-related gene expression in B. mori. In the present study, we treated mulberry leaves with CAP by the leaf-dipping method, and then B. mori larvae were continuously fed with the polluted mulberry leaves. Moreover, the detoxification enzyme activities and the expressions of detoxification-related genes in the fat body of B. mori were examined. The results showed that at 24 h after CAP exposure, the activities of P450 and GST enzymes were all significantly increased, with P450 enzymes responding fastest. CarE enzyme activity was up-regulated in 24 h, and then it was decreased compared with the control group. Furthermore, the expressions of the key genes in the PI3K/Akt/CncC signaling pathway (PI3K, PDK, Akt, CncC and Keap1) at the mRNA were significantly increased. Western blotting analysis revealed that Akt was inhibited at the protein level, resulting in decreased expression of Keap1 and increased expression of CncC. These results indicated that the PI3K/Akt/CncC signaling pathway in the fat body of B. mori responded to CAP exposure and regulated the expressions of downstream detoxification enzymes, thus enhancing the detoxifying capability of B. mori.

This study aimed to explore the toxicity of environmental residues of graphene oxide nanoparticles (GONPs) to reproduction of Lepidopteron insects using both ovary cell line (BmN) and individual female Bombyx mori as the research subjects. The results showed that GONPs dose dependently affect BmN cells. At higher concentrations (>25 mg/L), GONPs led to oxidative stress, ROS accumulation and DNA damage in BmN cells and significantly reduced their survival rate (p ≤ 0.05). Moreover, feeding female B. mori larvae with mulberry leaves treated with 25 mg/L GONPs significantly decreased their gonadosomatic index (GSI) by 40.84%, and increased oxidation levels and antioxidant enzyme activity in silkworm ovary tissues. Pathological analysis found that exposure to GONPs decreased the numbers of both oogonia and oocytes in ovarian tissues, increased the formation of peroxisome and vacuoles in follicle cells, reduced the transcription of genes (Vg, Ovo, Sxl-s, Sxl-l, and Otu) related to ovarian development in B. mori by 0.61, 0.65, 0.75, 0.72, and 0.42-fold, respectively, and lowered the amount of spawning by 52.25%. Overall, these results revealed that GONPs exposure is toxic to the reproduction of B. mori. The underlying mechanism is that oxidative stress due to GONPs causes oxidative damage to DNA, damages ovarian tissues, as well as hinders B. mori development and spawning. Thus, this study provides important experimental data for safety evaluation of reproductive toxicity due to GONPs exposure.

The high-temperature stress gene GrpE plays an important role in coping with high-temperature stress. The mutation of key sites of this gene can improve the high-temperature resistance of organisms. In the present study, using complementary DNAs from the silkworm fat body as the template, the open reading frame sequence of the GrpE gene (BmGrpE) was amplified and was found to be 644 bp in length and encode a protein with a predicted molecular weight of 24.1 kDa. The presence of a binding site for the heat shock transcription factor (Hsf1) at -1440 bp upstream of its coding region indicates that BmGrpE may respond to high-temperature stress. BmGrpE was constitutively expressed throughout developmental stages, with the highest level observed in the 5th instar larvae stage. Moreover, in 5th instar larvae (the 3th day), BmGrpE was expressed in all tissues examined, with the highest levels in the fat body, silk gland, and midgut. Interestingly, under high-temperature stress, TiO2 nanoparticle treatment increased the messenger RNA levels of BmGrpE in the fat body and silk gland. After treatment with dsRNA of BmGrpE, the cell viability of BmN cells was significantly decreased under 34°C and H2 O2 stress (p < .05). Mutation of BmGrpE (H163L) enhanced the resistance of BmN cells under high-temperature stress. These results provide new clues for the study of molecular mechanisms of insect resistance to high temperatures.

To determine the systematic status of family Limacodidae within Lepidoptera, the complete mitochondrial genome (mitogenome) of Thosea sinensis (Lepidoptera: Zygaenoidea: Limacodidae) was sequenced. The genome is 15,544 base pairs (bp), including 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and an AT-rich region. These characteristics are similar to of other lepidopterans. The gene order of T. sinensis is identical to that of Ditrysia lepidopterans. The nucleotide composition of the T. sinensis mitochondrial genome is highly biased toward A + T nucleotides (81.1%) and exhibits negative AT and GC skew. All the other 13 PCGs except cox1 are initiated by ATN codons. All tRNA genes are folded into the typical cloverleaf secondary structure, except for trnS1, which lacked the dihydrouridine (DHU) stem. There are 20 intergenic spacer regions ranging from 1 to 56 bp in length, and two gene overlap regions throughout the entire genome. The AT-rich region includes the ATAGA motif, followed by a 19-bp poly T stretch, a microsatellite-like (AT)10, and a poly-A element. Analysis of phylogenetic relationships indicated that T. sinensis belongs to the Limacodidae, and the monophyly of each lepidopteran family was well supported.

Acetamiprid is a new neonicotinoid insecticide widely used in the prevention and control of pests in agriculture. However, its residues in the environment affect the cocooning of the silkworm, Bombyx mori (B. mori), a non-target insect. To investigate the mechanism of damage, B. mori larvae were fed with trace amounts of acetamiprid (0.15 mg/L). At 96 h after exposure, the larvae showed signs of poisoning and decreased body weight, resulting in reduced survival and ratio of cocoon shell. At 48 h and 96 h after exposure, the residues in the posterior silk gland (PSG), which is responsible for synthesizing silk fibroin, were 0.72 μg/mg and 1.21 μg/mg, respectively, as measured by high performance liquid chromatography, indicating that acetamiprid can accumulate in the PSG. Moreover, pathological sections and transmission electron microscopy also demonstrate the damage of the PSG by acetamiprid. Digital gene expression (DGE) and KEGG pathway enrichment analysis revealed that genes related to metabolism, stress responses and inflammation were significantly up-regulated after exposure. Quantitative RT-PCR analysis showed that the transcript levels of FMBP-1 and FTZ-F1 (transcription factors for synthesizing silk protein) were up-regulated by 2.55-and 1.56-fold, respectively, and the transcript levels of fibroin heavy chain ( Fib-H), fibroin light chain (Fib-L), P25, Bmsage and Bmdimm were down-regulated by 0.75-, 0.76-, 0.65-, 0.44- and 0.40-fold, respectively. The results indicate that accumulated acetamiprid causes damage to the PSG and leads to reduced expression of genes responsible for synthesizing silk fibroin. Our data provide reference for evaluating the safety of acetamiprid residues in the environment for non-target insects.

Bombyx mori is an important economic insect. However, the environmental pollution caused by the widespread use of neonicotinoid insecticides has significantly affected the safe production of sericulture. In this paper, we determined the LC50 of acetamiprid, a kind of neonicotinoid insecticides, to 5th instar silkworm larvae, examined its residues in hemolymph and midgut of silkworm after continuous exposure to low-dose of acetamiprid, and investigated the transcription level of detoxifying-related genes and the activity of detoxifying enzymes. The results showed that acetamiprid was highly toxic (24-h LC50, 1.50 mg/L) to silkworm larvae. After continuous exposure to low-dose of acetamiprid (0.15 mg/L), the acetamiprid residue concentrations in hemolymph and midgut were 0.90 and 0.58 μg/mg, respectively, at 48 h, but all decreased at 96 h. At 24 h of acetamiprid exposure, the transcription levels of CYP4M5 and CYP6AB4 and the P450 enzyme activity were significantly enhanced. However, the transcription levels of CarE and CarE-11 and the activity of CarE enzymes were both inhibited by acetamiprid exposure. After 24 h–72 h of acetamiprid exposure, the transcription levels of GSTe3 and GSTd1 were significantly up-regulated, and the GST enzyme activity was also significantly elevated from 48 h to 96 h. Furthermore, the expression levels of FoxO, CncC and Keap1, the key upstream genes of detoxification enzymes, showed a similar trend as the GST genes. These results indicated that acetamiprid was reduced in midgut and the expression of GSTs was upregulated may via FoxO/CncC/Keap1 signaling pathway, which plays a key role in detoxification responses.

Silkworm (Bombyx mori) is an economic insect of the Lepidoptera. Chlorantraniliprole (CAP) exposure results in reduced growth and development of B. mori and failure in cocooning, seriously affecting the development of sericulture. To study the mechanisms underlying the damage to silkworm caused by sublethal doses of CAP, we examined the oxidative damage, the activities of digestive enzymes in midgut, and the expressions of midgut-related genes at the mRNA level. We found that CAP exposure inhibited the growth of silkworm, decreased the body mass and caused the accumulation of reactive oxygen species (ROS) [the levels of O2-, H2O2 and lipid peroxidation (MDA) were increased by 1.62-, 1.87- and 1.46-fold, respectively]. Moreover, we also found that the midgut cells were disintegrated, microvilli disappeared, the stroma became thinner, and the chromatin of nucleus became aggregated after CAP exposure by the analysis of transmission electron microscopy (TEM). In addition, the activities of digestive enzymes were dysregulated in midgut (the activities of α-amylase and trypsin were decreased 0.69- and 0.20-fold, respectively). Furthermore, digital gene expression (DGE) profiling analysis revealed that the expressions of oxidative phosphorylation pathway and antioxidant defense system related genes in midgut were decreased, indicating that it was the oxidative damage in midgut caused by CAP that mainly affected the growth of silkworm, rather than the toxicological effects of CAP. Collectively, this study provided valuable insights into the toxic effects of CAP on insects.

The ontogeny of macrophages in most organ/tissues in human body has been proven. Due to the limited number and inaccessibility of synovial macrophages (SM), the origin of SM has not been fully illuminated. The objective of this study was designed to investigate the ontogeny of SM and to evaluate the role of SM from different origins in arthritis. Two origins of SM, embryonic SM (ESM) and bone marrow SM (BMSM) were identified in Cx3cr1-EGFP mice, CCR2−/− mice and bone marrow (BM) chimera model by using a stringent sorting strategy. The cellular features, including dynamic total cell number, in situ proliferation, phagocytosis and expressions of pro-inflammatory and anti-inflammatory genes, of ESM and BMSM were compared. In addition, ESM and BMSM showed different expression patterns in Rheumatoid Arthritis (RA) patients' synovium and during the developmental process of collagen-induced arthritis (CIA) mice. Taken together, these results demonstrated that the SM at least has two origins, ESM and BMSM. The different cellular property and dynamic expression patterns in RA patients/CIA mice highlight the notion that ESM and BMSM might play different role in arthritis.

Tumor-associated macrophages (TAMs) are an important cellular component of the tumor microenvironment (TME) and play an essential role in tumor immunity. Recently, numerous studies have indicated that long non-coding RNAs (lncRNAs) can affect several functions of TAMs. In the present review, we summarize the versatile role of lncRNAs in the polarization, epigenetic modulation, and classic signaling pathways of TAMs, which represent a potential target for tumor diagnosis or treatment.

Sublethal doses of chlorantraniliprole (CAP) disrupt spinning disorder in the silkworm Bombyx mori (B. mori) and cause reduced cocoon production. In the present study, we investigated the effects of trace amounts of CAP on morphology and gene expression of the B. mori silk gland, found the posterior silk gland cells were possessed of disintegrated Endoplasmic reticulum (ER), unevenly distributed chromatin after exposure to CAP (0.01 mg/L). Gene expression analysis revealed that IRE1 and ATF6 ER stress-signaling pathways were inhibited, the PERK/CncC pathway was activated. Digital gene expression (DGE) analysis showed that detoxification-related genes, antioxidant genes and genes involved in ER protein processing pathway were expressed differentially in CAP-treated silkworm larvae. Notably, the transcript levels of the detoxification-related genes (CYP4M5, CYP6AB4, GSTD3 and GSTS1) and the antioxidant genes (CAT, TPX and SOD) were significantly increased, and the expression of ER protein processing-related genes (Sec61β, Sec61γ, Sec23α and ERGIC-53) was significantly decreased after CAP exposure. The results showed that sublethal doses of CAP exposure caused ER stress, oxidative damage to the silk gland and the perturbation of protein processing in ER, thereby probably leading to abnormal growth of the silk gland and triggering the spinning failure in silkworm.

Silkworm (Bombyx mori) is an economically important insect. However, the survival of silkworms has been significantly affected by the assault of chemical pesticides on mulberry trees through aerial application and water currents. Phoxim is a broad-spectrum organophosphorus insecticide widely used in China. Currently, very little is known about the non-neuronal effects of sublethal exposure to phoxim. The purpose of this study was to investigate the non-neuronal effects of sublethal phoxim exposure in the silkworm midgut, with a focus on nutrient metabolism. After phoxim treatment, lipase activity in the silkworm was shown to be up-regulated at 24 h before a decreasing trend was seen. Meanwhile, α-amylase activity showed the opposite trend. The expression levels of mitochondrial respiratory chain-related genes were all up-regulated at 24 h before falling continuously. To ensure that the effects of phoxim on nutrient metabolism were not simply a consequence of a decrease in mulberry consumption, the silkworms were treated with a reduced-food diet before the digestive enzyme activities and the transcription levels of mitochondrial respiratory chain-related genes were analyzed. Our results showed that the patterns in the reduced-diet and phoxim-exposed silkworm were markedly different, suggesting the alterations in the phoxim-exposed silkworm cannot readily be explained by nutrient deprivation

Acetamiprid is widely used for agricultural pest control. However, it remains poorly understood whether the environmental residues of acetamiprid have the potential effects on economic insect. In this study, we evaluated the effects of acetamiprid on silkworm growth and development. The exposure to trace amounts of acetamiprid significantly decreased body weight, viability, and spinning ability. In addition, the activity of trypsin in the midgut was decreased after exposure. DGE and KEGG pathway enrichment analysis revealed that the significantly differentially expressed genes were mainly involved in nutrient metabolism, stress responses, and inflammation pathways. These results, in combination with hematoxylin-eosin staining and transmission electron microscopy, indicated that acetamiprid could cause oxidative damage to midgut, lead to inflammatory responses, and affect the activities of midgut digestive enzymes, thus resulting in abnormal growth and development. Our findings greatly contributed to the evaluation of the effects of acetamiprid residues on other nontarget beneficial insect.

The plant extract “total glucosides of peony” (TGP) constitutes a mixture of glycosides that is isolated from the roots of the well-known traditional Chinese herb Paeonia lactiflora Pall. Paeoniflorin (Pae) is the most abundant component and the main biologically active ingredient of TGP. Pharmacologically, Pae exhibits powerful anti-inflammatory and immune regulatory effects in some animal models of autoimmune diseases including Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE). Recently, we modified Pae with an addition of benzene sulfonate to achieve better bioavailability and higher anti-inflammatory immune regulatory effects. This review summarizes the pharmacological activities of Pae and the novel anti-inflammatory and immunomodulatory agent Paeoniflorin-6′-O-benzenesulfonate (CP-25) in various chronic inflammatory and autoimmune disorders. The regulatory effects of Pae and CP-25 make them promising agents for other related diseases, which require extensive investigation in the future.

The global warming has affected the growth, development and reproduction of insects. However, the molecular mechanism of high temperature stress-mediated metamorphosis regulation of lepidopteran insect has not been elucidated. In this study, the relationship between the insect developmental process and endogenous hormone level was investigated under high temperature (36 ° C) stress inBombyx mori(B. mori). The results showed that the duration of 5thinstar larvae were shortened by 28 ± 2 h, and the content of 20E was up-regulated significantly after 72 h of high temperature treatment, while the transcription levels of 20E response genesE93, Br-C, USP, E75were up-regulated 1.35, 1.25, 1.28, and 1.27-fold, respectively. The high temperature treatment promoted the phosphorylation level of Akt and the downstream BmCncC/keap1 pathway was activated, the transcription levels of 20E synthesis-related genescyp302a1, cyp306a1, cyp314a1andcyp315a1were up-regulated by 1.12, 1.51, 2.17 and 1.23-fold, respectively. After treatment with double stranded RNA of BmCncC (dsBmCncC) in BmN cells, the transcription levels ofcyp302a1andcyp306a1were significantly decreased, whereas up-regulated by 2.15 and 1.31-fold, respectively, after treatment with CncC activator Curcumin. These results suggested that BmCncC/keap1-mediated P450 genes (cyp302a1, cyp306a1) expression resulted in the changes of endogenous hormone level, which played an important role in the regulation of metamorphosis under high temperature stress. Studies provide novel clues for understanding the CncC/keap1 pathway-mediated metamorphosis regulation mechanism in insects.Author SummaryMammalian nuclear transcription factor Nrf2 (NF-E2-related factor 2) plays an important role in the stress response of cells. CncC is a homolog of mammalian Nrf2 in insect, regulating the genes expression of insect antioxidant enzymes and cytochrome P450 detoxification enzyme. Evidence suggests that the CncC/Keap1 pathway also plays an important role in regulating insect development. Here, we investigated the regulatory mechanism between the CncC/Keap1 pathway and metabolism of silkworm hormones in Lepidoptera. We found that high temperature induction accelerated the development of silkworm, the ecdysone content and related metabolic genes in hemolymph were significantly up-regulated, the CncC/Keap1 pathway was activated, and the expression ofBmCncCwas significantly increased, indicating that the Cncc/Keap1 pathway plays an important role in this process. The expression ofcyp302a1andcyp306a1was significantly decreased by RNA interference withBmCncC, which indicated that CncC in silkworm had a regulatory relationship with downstream 20E synthetic gene. In summary, the results indicate that the CncC/Keap1 pathway plays an important role in regulating hormone metabolism in silkworm, providing a basis for further study of the relationship between CncC/Keap1 pathway and development in insects.

Organophosphate pesticides are widely applied worldwide for agricultural purposes, and their exposures often result in adverse effects on Bombyx mori. The insect gut is a complicated ecosystem inhabited by a large number of microbes that play important roles in insect physiology and behavior. Recent studies have reported that alteration of their microbiota due to stressful conditions or environmental changes has been linked to a compromised health status and a susceptibility to diseases. In the present study, we aimed to assess the effects of phoxim exposure on intestinal microbes in silkworms. The results showed that phoxim exposure increased the bacterial community evenness and altered the structure of gut microbiota in silkworm larvae. The abundances of several genera, such as Methylobacterium and Aurantimonadaceae, in phoxim-treated larval guts were significantly reduced compared with the H2O-treated group, whereas the abundances of non-dominant bacteria, such as Staphylococcus, were significantly increased. Moreover, phoxim inhibited the expressions of antimicrobial peptides (AMPs) at the mRNA level and enhanced the pathogenesis of Enterobacter cloacae (E. cloacae) against silkworm larvae, suggesting that the immune system was inhibited after phoxim exposure. Therefore, the gut microbial community shifts were apparent after phoxim exposure. The compositional and structural changes of intestinal microbes caused by phoxim exposure might affect the normal function of the intestinal tract of silkworm. These results highlighted the importance of the gut bacterial community when investigating the mechanisms of midgut injury after pesticide exposure in Bombyx mori.

The widespread use of nanomaterials has raised concerns about the potential impact of nanoparticles on human health and the natural environment. Although high doses of TiO2 nanoparticles (NPs) are toxic to animals, low doses of TiO2 NPs have been shown to benefit their growth and immune functions. Intestinal microorganisms are critical in maintaining the normal life activities and ensuring the health of their host. The intestinal microorganisms of lepidopteran insects can promote growth and development, foster insecticide resistance, and improve resilience against diseases. However, to date, there is no report on the effects of TiO2 NPs on the intestinal microbiota of lepidopteran insects. In this work, we examined the effects of a low dose of TiO2 NPs (5 mg/L) on the intestinal microbiota of silkworm (Bombyx mori). The results showed that the exposure to TiO2 NPs did not alter the dominant species of intestinal microbiota significantly, but changed the abundance of individual species of intestinal microorganisms. Specifically, exposure to TiO2 NPs increased the uniformity of intestinal microorganisms. The abundance of Lachnospiraceae_NK4A136_group, involved in the metabolism of nutrients, as well as the abundance of Pseudomonas and Sphingomonas, both involved in detoxification and disease resistance, was increased. Meanwhile, among the non-dominant species, the conditional pathogenic bacteria Serratia exhibited decreased abundance. In addition, exposure to TiO2 NPs also increased the abundance of norank_f_Bacteroidales_S24-7_group, which could help relieve inflammation and regulate immune functions. The current study is the first to report the effects of TiO2 NPs on the intestinal microbiota of lepidopteran insects. The results demonstrated that TiO2 NPs could alter the composition of the intestinal microbiota of B. mori, and thus promote its growth and development, regulate its immune functions, and enhance its resistance to insecticide.

Fresh leachate from municipal solid waste (MSW) incineration plant in China always contains extremely high concentration of calcium which would reduce the bioactivity of microorganisms and lead to calcium precipitation in granules. This paper investigated the effect of high concentration of calcium on anaerobic granular sludge without calcium precipitation by static tests for 72 h, and on anaerobic bio-treatment process for treating fresh leachate in a laboratory-scale expanded granular sludge bed (EGSB) reactor with calcium precipitation for 132 d. The results showed that, suppression thresholds of calcium concentration for anaerobic granular sludge were 5000 mg/L from both static tests and EGSB reactor operation. Calcium precipitation in anaerobic granules was a gradual formation process, mainly in the form of calcium carbonate calcite. Compared with calcium precipitation, high calcium concentration was mainly responsible for the decrease of COD removal efficiency in treatment process. Only a few microorganisms survived when calcium concentration increased over 5000 mg/L, which was mainly concentrated in Clostridium of bacteria and Methanosaeta of archaea.