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The smoky brown cockroach, Periplaneta fuliginosa , is a peridomestic pest inhabiting broad regions of the world from temperate to subtropical zones. In common with other related species such as the American cockroach, Periplaneta americana , female-emitted sex pheromone components, named periplanones, are known to be key volatiles that elicit long-range attraction and courtship rituals in males. How periplanones are processed in the nervous system has been entirely unexplored in P. fuliginosa . By using pheromone compounds, periplanones A, B, C, and D, as stimulants to the antenna, we identified four distinct types of interneurons (projection neurons) that relay pheromonal signals from a single olfactory glomerulus of the first-order olfactory center (antennal lobe) to higher-order centers in the ipsilateral hemibrain. All glomeruli innervated by pheromone-responsive projection neurons clustered near the antennal nerve entrance of the antennal lobe. The projection neuron with dendrites in the largest glomerulus was tuned specifically to periplanone-D, and adding other components to periplanone-D counteracted the excitation elicited by periplanone-D alone. Likewise, the projection neuron with dendrites in the second largest glomerulus and that with dendrites in a medium-sized glomerulus were tuned to periplanone-A and periplanone-B, respectively. Our results are, therefore, consistent with behavioral findings that periplanone-D alone acts as a primary sex attractant and that other components act as potential behavioral antagonists. Moreover, a comparison of the glomeruli in P. fuliginosa and P. americana suggested that there are differences in the sizes of homologous glomeruli, as well as in the ligands they process.

Evolution of resistance among insects to action of pesticides has led to the discovery of several insecticides (neonicotinoids and organophosphates) with new targets in insect nervous system. Present study evaluates the mode of inhibition of acetylchlonesterase (AChE), biochemical efficacy, and molecular docking of 2,3-dimethylmaleic anhydride, against Periplaneta americana and Sitophilus oryzae . The knockdown activity of 2,3-dimethylmaleic anhydride was associated with in vivo inhibition of AChE. At KD 99 dosage, the 2,3-dimethylmaleic anhydride showed more than 90% inhibition of AChE activity in test insects. A significant impairment in antioxidant system was observed, characterized by alteration in superoxide dismutase and catalase activities along with increase in reduced glutathione levels. Computational docking programs provided insights in to the possible interaction between 2,3-dimethylmaleic anhydride and AChE of P . americana . Our study reveals that 2,3-dimethylmaeic anhydride elicits toxicity in S . oryzae and P . americana primarily by AChE inhibition along with oxidative stress.

We present new records of four introduced cockroaches of medical importance for the state of Nuevo Leon, Mexico: the German cockroach (Blattella germanica; Linnaeus, 1767), of the family Blattellidae; the large brown cockroach (Periplaneta brunnea; Burmeister, 1838) and Turkestan cockroach (Periplaneta lateralis; Walker, 1868), of the family Blattidae; and the brown-banded cockroach (Supella longipalpa; Fabricius, 1798), of the family Pseudophyllodromiidae. We also record new locations in the state for the harlequin cockroach (Neostylopyga rhombifolia; Stoll, 1813), the American cockroach (Periplaneta americana; Linnaeus, 1758), and the Australian cockroach (Periplaneta australasiae; Fabricius, 1775). The present records increase the known diversity of cockroaches from the state of Nuevo Leon from 11 to 15 species. We present additional state records for N. rhombifolia for Ciudad de Mexico, Estado de Mexico, and Puebla; P. americana for Baja California, Chiapas, Guerrero, Michoacan, Oaxaca, Quintana Roo, and San Luis Potosi; P. australasiae for Campeche, Ciudad de Mexico, Hidalgo, Jalisco, Michoacan, San Luis Potosi, and Tabasco; and P. brunnea for Ciudad de Mexico and Guerrero. Presentamos nuevos registros de cuatro cucarachas introducidas y de importancia médica para el estado de Nuevo León, México: la cucaracha alemana Blattella germanica (Linnaeus, 1767) de la familia Blattellidae; la cucaracha café grande Periplaneta brunnea Burmeister, 1838 y la cucaracha de Turkestán Periplaneta lateralisWalker, 1868 de la familia Blattidae; y la cucaracha de bandas cafés Supella longipalpa (Fabricius, 1798) de la familia Pseudophyllodromiidae. También registramos nuevas localidades en el estado para la cucaracha arlequín Neostylopyga rhombifolia (Stoll, 1813), la cucaracha americana Periplaneta americana (Linnaeus, 1758) y la cucaracha australiana Periplaneta australasiae (Fabricius, 1775). Los registros actuales aumentan la diversidad conocida de cucarachas del estado de Nuevo León de 11 a 15 especies. Presentamos registros estatales adicionales de N. rhombifolia para Ciudad de México, Estado de México y Puebla; P. americana para Baja California, Chiapas, Guerrero, Michoacán, Oaxaca, Quintana Roo y San Luis Potosí; P. australasiae para Campeche, Ciudad de México, Hidalgo, Jalisco, Michoacán, San Luis Potosí y Tabasco; y P. brunnea de Ciudad de México y Guerrero.

Cockroaches are surrogate hosts for microbes that cause many human diseases. In spite of their generally destructive nature, cockroaches have recently been found to harbor potentially beneficial and medically useful substances such as drugs and allergens. However, genomic information for the American cockroach (Periplaneta americana) is currently unavailable; therefore, transcriptome and gene expression profiling is needed as an important resource to better understand the fundamental biological mechanisms of this species, which would be particularly useful for the selection of novel antimicrobial peptides. Thus, we performed de novo transcriptome analysis of P. americana that were or were not immunized with Escherichia coli. Using an Illumina HiSeq sequencer, we generated a total of 9.5 Gb of sequences, which were assembled into 85,984 contigs and functionally annotated using Basic Local Alignment Search Tool (BLAST), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) database terms. Finally, using an in silico antimicrobial peptide prediction method, 86 antimicrobial peptide candidates were predicted from the transcriptome, and 21 of these peptides were experimentally validated for their antimicrobial activity against yeast and gram positive and -negative bacteria by a radial diffusion assay. Notably, 11 peptides showed strong antimicrobial activities against these organisms and displayed little or no cytotoxic effects in the hemolysis and cell viability assay. This work provides prerequisite baseline data for the identification and development of novel antimicrobial peptides, which is expected to provide a better understanding of the phenomenon of innate immunity in similar species.

Although Periplaneta americana L. and its modern preparation, Kangfuxin liquid, have been extensively applied for ulcerative diseases in gastrointestinal tract (e.g., gastric ulcer (GU) and ulcerative colitis, the effective components and potential mechanisms) remain unclear. In accordance with the accumulating research evidences, the relieving/exacerbating of GU is noticeably correlated to focal tissue programmed cell death. Herein, gastro-protective effects of the effective Periplaneta americana L. extract (PAE) fraction were assessed in vitro and in vivo , involving in programmed cell death-related signaling channels. To screen the effective PAE fraction exerting gastroprotective effects, several PAE fractions were gained based on a wide range of ethanol solution concentration, and they were assessed on ethanol-induced ulcer mice. Based on HPLC investigation with the use of nucleosides, the chemical composition of screened effective PAE, extracted by 20% ethanol, was analyzed in terms of quality control. Based on CCK-8 assay, the protective effects on GES-1 cells, impaired by ethanol, of PAE were assessed. After 3 days pre-treatment with PAE (200, 400, 800 mg/kg), the gastric lesions were assessed by tissue morphology, and periodic acid-schiff (PAS) staining, as well as hematoxylin and eosin (H&E) based histopathology-related investigation. The levels for inflammation cytokines (IL1-β, TNF-α, IL-18, PGE2, and IL-6), antioxidant indices (SOD and MDA) were examined via ELISA. In the meantime, based on Western Blotting assay, the expression levels of some programmed cell death-related protein targets (NLRP3, caspase-1, NF-κB p65, MyD88, and TLR4) were analyzed. As revealed from the results, PAE is capable of alleviating gastric mucosa impairment, suppressing the inflammatory cytokines, and down-regulating the MyD88/NF-κB channels. Accordingly, 20% ethanol extract of Periplaneta americana L. would contribute its gastroprotective effects, thereby providing the evidence that its anti-GU mechanisms correlated with inhibiting programmed cell death channel.

Recurrent oral ulcers (ROUs) of oral mucosa disease are difficult to cure and relapse easily, and immune imLbalance or dysfunction is considered an essential factor in their occurrence and recurrence. Periplaneta americana extract (PAD), a raw material used in Kangfuxin Liquid and Yunnan Baiyao toothpaste, contains a variety of growth factors such as polypeptides and sticky sugar amino acids that promote tissue repair; this can encourage the growth of the granulation tissue and reduce inflammation on the wound surface. This study aimed to investigate the interventional potential of PAD on recurrent oral ulcers in rats and to elucidate the underlying mechanism of action involving the TLR4/NF-κB and Nrf2/HO-1 signaling pathways. A rat model of recurrent oral ulcer (ROU) was established using an oral antigen emulsifier. Rats in the ROU group were administered PAD by gavage for 7 days. To observe the effect of PDA on ROU mice. HE staining revealed that PAD restored the structure of the oral mucosal tissue and reduced inflammatory infiltration. FCM revealed that PAD upregulated CD3 + and CD4 + levels and the CD4 + /CD8 + ratio in peripheral blood T lymphocytes. ELISA revealed that PAD increased the content of IgA, IgG, IgM, VEGF, IL-2, and IL-10, while decreasing IL-6 and TNF-α content. Microplate analysis revealed that PAD significantly increased CAT content in the serum of ROU rats and reduced GSH, NO, SOD, and MDA levels. IHC staining, RT-qPCR, and Western blotting revealed that PAD downregulated Keap1 and IκBα expression, inhibited the TLR4/NF-κB signaling pathway, upregulated Nrf2 and HO-1 expression, and activated the Nrf2/HO-1 signaling pathway. These fndings suggest that PAD improved immune imbalance and oxidative stress in ROU rats by activating the Nrf2/HO-1 pathway and inhibiting the TLR4/NF-κB signaling pathway, thereby promoting the healing of oral ulcer wounds.

In “excitable” cells, like neurons and muscle cells, a difference in electrical potential is used to transmit signals across the cell membrane. This difference is regulated by opening or closing ion channels in the cell membrane. For example, mutations in human voltage-gated sodium (Na v ) channels are associated with disorders such as chronic pain, epilepsy, and cardiac arrhythmia. Pan et al. report the high-resolution structure of a human Na v channel, and Shen et al. report the structures of an insect Na v channel bound to the toxins that cause pufferfish and shellfish poisoning in humans. Together, the structures give insight into the molecular basis of sodium ion permeation and provide a path toward structure-based drug discovery. Science , this issue p. eaau2486 , p. eaau2596 Structures provide insight into how voltage-gated sodium channels function and how they can be inhibited. Animal toxins that modulate the activity of voltage-gated sodium (Na v ) channels are broadly divided into two categories—pore blockers and gating modifiers. The pore blockers tetrodotoxin (TTX) and saxitoxin (STX) are responsible for puffer fish and shellfish poisoning in humans, respectively. Here, we present structures of the insect Na v channel Na v PaS bound to a gating modifier toxin Dc1a at 2.8 angstrom-resolution and in the presence of TTX or STX at 2.6-Å and 3.2-Å resolution, respectively. Dc1a inserts into the cleft between VSD II and the pore of Na v PaS, making key contacts with both domains. The structures with bound TTX or STX reveal the molecular details for the specific blockade of Na + access to the selectivity filter from the extracellular side by these guanidinium toxins. The structures shed light on structure-based development of Na v channel drugs.

Fatigue is an increasingly prominent global health issue. Periplaneta americana glycoprotein (PAG) possesses multiple pharmacological activities including antioxidation, regulation of gut microbiota (GM) and immunity, which are highly consistent with the targets of anti-fatigue treatment. This study aimed to investigate the efficacy and mechanisms of PAG in anti-fatigue. Initially, the antioxidant activity of PAG was evaluated in vitro. Subsequently, a fatigue mouse model was established to evaluate its anti-fatigue effects in vivo. Finally, Spearman correlation analysis was conducted to explore correlations between gut microbiota shifts, short-chain fatty acid (SCFA) production, and fatigue indicators. The results showed that PAG possesses significant antioxidant activity. Furthermore, PAG alleviated fatigue through multiple pathways: it prolonged swimming time, ameliorated liver injury, increased the activities of liver glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), reduced liver malondialdehyde (MDA) levels, decreased serum blood urea nitrogen (BUN) and muscle lactic acid (LA) accumulation, inhibited serum lactate dehydrogenase (LDH) and creatine kinase (CK) activities, promoted glycogen storage in the liver and muscles of fatigued mice, altered the composition and structure of GM, and increased SCFA levels. In conclusion, these findings demonstrate that PAG alleviates fatigue by improving oxidative stress, regulating energy metabolism, and modulating the GM–SCFA axis.

The effects of starvation on cell death in the midgut of Periplaneta americana were studied histochemically and ultrastructurally. TUNEL assays showed that cell death began to increase in the columnar cells and nidi, the nests of stem cells and newborn cells from 2 weeks of starvation. A significant increase in cell death occurred in the nidi after 4 weeks of starvation. Cockroaches starved for 4 weeks showed active-caspase-3-like immuno-reactivity both in the columnar cells and nidi, whereas control cockroaches that were fed for 4 weeks showed this reactivity only in the apical cytoplasm of columnar cells. Electron microscopy revealed no chromatin condensation in the nucleus of columnar cells of cockroaches, whether fed or starved for 4 weeks. Starved cockroaches exhibited many small vacuoles in the cytoplasm of some columnar cells and “floating” organelles including nuclei in the lumen. A 4-week starvation induced the appearance of cytoplasmic fragmentation and secondary lysosomes in the nidi. Each fragment contained nuclear derivatives with condensed chromatin, i.e. apoptotic bodies. Mitotic cells were found in some, but not all nidi, even within the same starved sample. Fragmentation was not observed in the nidi of control cockroaches. Thus, starvation increases cell death not only in the columnar cells, but also in the nidi. The cell death in the nidi is presumably apoptosis executed by caspase 3.

Nitrogen acquisition and assimilation is a primary concern of insects feeding on diets largely composed of plant material. Reclaiming nitrogen from waste products provides a rich reserve for this limited resource, provided that recycling mechanisms are in place. Cockroaches, unlike most terrestrial insects, excrete waste nitrogen within their fat bodies as uric acids, postulated to be a supplement when dietary nitrogen is limited. The fat bodies of most cockroaches are inhabited by Blattabacterium, which are vertically transmitted, Gram-negative bacteria that have been hypothesized to participate in uric acid degradation, nitrogen assimilation, and nutrient provisioning. We have sequenced completely the Blattabacterium genome from Periplaneta americana. Genomic analysis confirms that Blattabacterium is a member of the Flavobacteriales (Bacteroidetes), with its closest known relative being the endosymbiont Sulcia muelleri, which is found in many sap-feeding insects. Metabolic reconstruction indicates that it lacks recognizable uricolytic enzymes, but it can recycle nitrogen from urea and ammonia, which are uric acid degradation products, into glutamate, using urease and glutamate dehydrogenase. Subsequently, Blattabacterium can produce all of the essential amino acids, various vitamins, and other required compounds from a limited palette of metabolic substrates. The ancient association with Blattabacterium has allowed cockroaches to subsist successfully on nitrogen-poor diets and to exploit nitrogenous wastes, capabilities that are critical to the ecological range and global distribution of cockroach species.