Neuropeptides are crucial in regulation of a rich variety of developmental,physiological,and behavioral functions throughout the life cycle of insects.Using an integrated approach of multiomics,we identified neuropeptide precursors in the greater wax moth Galleria mellonella,which is a harmful pest of honeybee hives with a worldwide distribution.Here,a total of 63 and 67 neuropeptide precursors were predicted and annotated in the G.mellonella genome and transcriptome,in which 40 neuropeptide precursors were confirmed in the G.mellonella peptidome.Interestingly,we identified 12 neuropeptide precursor genes present in G.mellonella but absent in honeybees,which may be potential novel pesticide target sites.Honeybee hives were contaminated with heavy metals such as lead,enabling its bioaccumulation in G.mellonella bodies through the food chain,we performed transcriptome sequencing to analyze the effects of Pb stress on the mRNA expression level of G.mellonella neuropeptide precursors.After treatment by Pb,the expression of neuropeptide F1 was found to be significantly downregulated,implying that this neuropeptide might be associated with responding to the heavy metal stress in G.mellonella.This study comprehensively identified neuropeptide precursors in G.mellonella,and discussed the effects of heavy metals on insect neuropeptides,with the example of G.mellonella.The results are valuable for future elucidation of how neuropeptides regulate physiological functions in G.mellonella and contribute to our understanding of the insect's environmental plasticity and identify potential new biomarkers to assess heavy metal toxicity in insects.
Pheretima,also called“earthworms”,is a well-known animal-derived traditional Chinese medicine that is extensively used in over 50 Chinese patent medicines(CPMs)in Chinese Pharmacopoeia(2020 edition).However,its zoological origin is unclear,both in the herbal market and CPMs.In this study,a strategy for integrating in-house annotated protein databases constructed from close evolutionary relationship-sourced RNA sequencing data from public archival resources and various sequencing algorithms(restricted search,open search,and de novo)was developed to characterize the phenotype of natural peptides of three major commercial species of Pheretima,including Pheretima aspergillum(PA),Pheretima vulgaris(PV),and Metaphire magna(MM).We identified 10,477 natural peptides in the PA,7,451 in PV,and 5,896 in MM samples.Five specific signature peptides were screened and then validated using synthetic peptides;these demonstrated robust specificity for the authentication of PA,PV,and MM.Finally,all marker peptides were successfully applied to identify the zoological origins of Brain Heart capsules and Xiaohuoluo pills,revealing the inconsistent Pheretima species used in these CPMs.In conclusion,our integrated strategy could be used for the in-depth characterization of natural peptides of other animal-derived traditional Chinese medicines,especially non-model species with poorly annotated protein databases.
Extensive effort has been devoted to the discovery,development,and validation of biomarkers for early disease diagnosis and prognosis as well as rapid evaluation of the response to therapeutic interventions.Genomic and transcriptomic profiling are well-established means to identify disease-associated biomarkers.However,analysis of disease-associated peptidomes can also identify novel peptide biomarkers or signatures that provide sensitive and specific diagnostic and prognostic information for specific malignant,chronic,and infectious diseases.Growing evidence also suggests that peptidomic changes in liquid biopsies may more effectively detect changes in disease pathophysiology than other molecular methods.Knowledge gained from peptide-based diagnostic,therapeutic,and imaging approaches has led to promising new theranostic applications that can increase their bioavailability in target tissues at reduced doses to decrease side effects and improve treatment responses.However,despite major advances,multiple factors can still affect the utility of peptidomic data.This review summarizes several remaining challenges that affect peptide biomarker discovery and their use as diagnostics,with a focus on technological advances that can improve the detection,identification,and monitoring of peptide biomarkers for personalized medicine.
