Do efficacy results obtained from randomized controlled trials translate to effectiveness data from observational studies for relapsing-remitting multiple sclerosis?

BACKGROUND: Randomized controlled trials are considered the gold standard in regulatory decision making, as observational studies are known to have important methodological limitations. However, real-world evidence may be helpful in specific situations. This review investigates how the effect estimates obtained from randomized controlled trials compare to those obtained from observational studies, using drug therapy for relapsing-remitting multiple sclerosis as an example. STUDY DESIGN AND SETTING: A systematic review of randomized controlled trials and observational studies was conducted. The primary outcome was the annualized relapse rate. Using (network) meta-analysis together with posterior predictive distributions, the drug-specific rate ratios from the network of randomized controlled trials were compared with those from the network of observational studies. RESULTS: Effect estimates from 26 observational studies showed greater magnitudes and were less precise compared to estimates obtained from 21 randomized controlled trials. Twenty of the 28 treatment comparisons between designs had similar rate ratios. Seven inconsistencies in observed rate ratios could be attributed to two specific disease-modifying therapies. CONCLUSION: In this case study, estimates from observational studies predominantly agreed with estimates from randomized controlled trials given their posterior predictive distributions. Multiple observational studies together may therefore supplement additional pivotal randomized controlled trials in relapsing-remitting multiple sclerosis, for instance facilitating the extrapolation of trial results to the broader patient population.

Epsilon-poly-l-lysine microneedle patch loaded with amorphous doxycycline nanoparticles for synergistic treatment of skin infection.

The development of antibiotic-loaded microneedles has been hindered for years by limited excipient options, restricted drug-loading space, poor microneedle formability, and short-term drug retention. Therefore, this study proposes a dissolving microneedle fabricated from the host-defense peptide ε-poly-l-lysine (EPL) as an antibacterial adjuvant system for delivering antibiotics. EPL serves not only as a major matrix material for the microneedle tips, but also as a broad-spectrum antibacterial agent that facilitates the intracellular accumulation of the antibiotic doxycycline (DOX) by increasing bacterial cell membrane permeability. Furthermore, the formation of physically crosslinked networks of EPL affords microneedle tips with improved formability, good mechanical properties, and amorphous nanoparticles (approximately 7.2 nm) of encapsulated DOX. As a result, a high total loading content of both antimicrobials up to 2319.1 µg/patch is achieved for efficient transdermal drug delivery. In a Pseudomonas aeruginosa-induced deep cutaneous infection model, the EPL microneedles demonstrates potent and long-term effects by synergistically enhancing antibiotic activities and prolonging drug retention in infected lesions, resulting in remarkable therapeutic efficacy with 99.91 % (3.04 log) reduction in skin bacterial burden after a single administration. Overall, our study highlights the distinct advantages of EPL microneedles and their potential in clinical antibacterial practice when loaded with amorphous DOX nanoparticles.

Comparison of antipsychotic drug use in children and adolescents in the Netherlands before and during the COVID-19 pandemic.

This study aims to describe the patterns and trends in antipsychotic prescription among Dutch youth before and during the corona virus disease 2019 (COVID-19) pandemic (between 2017 and 2022). The study specifically aims to determine whether there has been an increase or decrease in antipsychotic prescription among this population, and whether there are any differences in prescription patterns among different age and sex groups. The study utilized the IADB database, which is a pharmacy prescription database containing dispensing data from approximately 120 community pharmacies in the Netherlands, to analyze the monthly prevalence and incidence rates of antipsychotic prescription among Dutch youth before and during the pandemic. The study also examined the prescribing patterns of the five most commonly used antipsychotics and conducted an autoregressive integrated moving average (ARIMA) analysis using data prior to the pandemic, to predict the expected prevalence rate during the pandemic. The prescription rate of antipsychotics for Dutch youth was slightly affected by the pandemic, with a monthly prevalence of 4.56 [4.50-4.62] per 1000 youths before COVID-19 pandemic and 4.64 [4.59-4.69] during the pandemic. A significant increase in prevalence was observed among adolescent girls aged 13-19 years. The monthly incidence rate remained stable overall, but rose for adolescent girls aged 13-19 years. Aripiprazole, and Quetiapine had higher monthly prevalence rates during the pandemic, while Risperidone and Pipamperon had lower rates. Similarly, the monthly incidence rates of Aripiprazole and Olanzapine went up, while Risperidone went down. Furthermore, the results from the ARIMA analysis revealed that despite the pandemic, the monthly prevalence rate of antipsychotic prescription was within expectation. The findings of this study suggest that there has been a moderate increase in antipsychotic prescription among Dutch youth during the COVID-19 pandemic, particularly in adolescent females aged 13-19 years. However, the study also suggests that factors beyond the pandemic may be contributing to the rise in antipsychotic prescription in Dutch youth.

Community Use of Repurposed Drugs Before and During COVID-19 Pandemic in the Netherlands: An Interrupted Time-Series Analysis.

Background: Repurposing registered drugs could reduce coronavirus disease (COVID-19) burden before novel drugs are authorized. Little is known about how the pandemic and imposed restrictions changed their dispensing. We aimed to investigate the impact of COVID-19 pandemic on repurposed drugs dispensing in the Netherlands. Methods: We performed interrupted time-series study using University of Groningen prescription database IADB.nl to evaluate dispensing trends of 24 repurposed drugs before (2017-February 2020) and after (March 2020-2021) the pandemic' start. Primary outcomes were monthly prevalence and incidence rates. An autoregressive integrated moving average model assessed the effect of pandemic and stringency index (measuring strictness of government's restriction policies). Results: Annual number of IADB.nl population ranged from 919,697 to 952,400. Generally, dispensing of common long-term-used drugs was not significantly affected by pandemic. The prevalence of antibacterials (-4.20 users per 1000 people), antivirals (-0.04), corticosteroids (-1.29), prednisolone (-1.32), calcium channel blocker (-0.41), and diuretics (-1.29) was lower than expected after the pandemic's start, while the prevalence of ivermectin (0.07), sulfonylureas (0.15), sodium-glucose co-transporter-2 (SGLT2) inhibitor (0.17), and anticoagulants (1.95) was higher than expected. The pandemic was associated with statistically significant decreases in the incidence of antibacterials (-1.21), corticosteroids (-0.60), prednisolone (-0.64) and anticoagulants (-0.02), and increases in ivermectin (0.02), aggregated antidiabetic drugs (0.13), and SGLT2 inhibitors (0.06). These trends were positively associated with pandemic and negatively associated with stringency index. Conclusion: Dispensing of most drugs was not significantly associated with pandemic and government's response. Despite some statistically significant disruptions, these were not necessarily clinically relevant due to small absolute differences observed.

Repurposed drug studies on the primary prevention of SARS-CoV-2 infection during the pandemic: systematic review and meta-analysis.

OBJECTIVE: Current evidence on the effectiveness of SARS-CoV-2 prophylaxis is inconclusive. We aimed to systematically evaluate published studies on repurposed drugs for the prevention of laboratory-confirmed SARS-CoV-2 infection and/or COVID-19 among healthy adults. DESIGN: Systematic review. ELIGIBILITY: Quantitative experimental and observational intervention studies that evaluated the effectiveness of repurposed drugs for the primary prevention of SARS-CoV-2 infection and/or COVID-19 disease. DATA SOURCE: PubMed and Embase (1 January 2020-28 September 2022). RISK OF BIAS: Cochrane Risk of Bias 2.0 and Risk of Bias in Non-Randomised Studies of Interventions tools were applied to assess the quality of studies. DATA ANALYSIS: Meta-analyses for each eligible drug were performed if ≥2 similar study designs were available. RESULTS: In all, 65 (25 trials, 40 observational) and 29 publications were eligible for review and meta-analyses, respectively. Most studies pertained to hydroxychloroquine (32), ACE inhibitor (ACEi) or angiotensin receptor blocker (ARB) (11), statin (8), and ivermectin (8). In trials, hydroxychloroquine prophylaxis reduced laboratory-confirmed SARS-CoV-2 infection (risk ratio: 0.82 (95% CI 0.74 to 0.90), I2=48%), a result largely driven by one clinical trial (weight: 60.5%). Such beneficial effects were not observed in observational studies, nor for prognostic clinical outcomes. Ivermectin did not significantly reduce the risk of SARS-CoV-2 infection (RR: 0.35 (95% CI 0.10 to 1.26), I2=96%) and findings for clinical outcomes were inconsistent. Neither ACEi or ARB were beneficial in reducing SARS-CoV-2 infection. Most of the evidence from clinical trials was of moderate quality and of lower quality in observational studies. CONCLUSIONS: Results from our analysis are insufficient to support an evidence-based repurposed drug policy for SARS-CoV-2 prophylaxis because of inconsistency. In the view of scarce supportive evidence on repurposing drugs for COVID-19, alternative strategies such as immunisation of vulnerable people are warranted to prevent the future waves of infection. PROSPERO REGISTRATION NUMBER: CRD42021292797.

The downregulation of HSP90-controlled CRALBP expression is associated with age-related vision attenuation.

The dysfunction of CRALBP, a key regulator of the visual cycle, is associated with retinitis punctata albescens characterized by night vision loss and retinal degeneration. In this paper, we find that the expression of CRALBP is regulated by heat shock protein 90 (HSP90). Inhibition of HSP90α or HSP90ß expression by using the CRISPR-Cas9 technology downregulates CRALBP's mRNA and protein expression in ARPE-19 cells by triggering the degradation of transcription factor SP1 in the ubiquitin-proteasome pathway. SP1 can bind to CRALBP's promoter, and inhibition of SP1 by its inhibitor plicamycin or siRNA downregulates CRALBP's mRNA expression. In the zebrafish, inhibition of HSP90 by the intraperitoneal injection of IPI504 reduces the thickness of the retinal outer nuclear layer and Rlbp1b mRNA expression. Interestingly, the expression of HSP90, SP1, and CRALBP is correlatedly downregulated in the senescent ARPE-19 and Pig primary RPE cells in vitro and in the aged zebrafish and mouse retinal tissues in vivo. The aged mice exhibit the low night adaption activity. Taken together, these data indicate that the HSP90-SP1 is a novel regulatory axis of CRALBP transcriptional expression in RPE cells. The age-mediated downregulation of the HSP90-SP1-CRALBP axis is a potential etiology for the night vision reduction in senior people.

Distinct Responses of Thitarodes xiaojinensis ß-1,3-Glucan Recognition Protein-1 and Immulectin-8 to Ophiocordyceps sinensis and Cordyceps militaris Infection.

Melanization and encapsulation are prominent defense responses against microbes detected by pattern recognition receptors of their host insects. In the ghost moth Thitarodes xiaojinensis, an activated immune system can melanize and encapsulate the fungus Cordyceps militaris However, these responses were hardly detected in the host hemolymph postinfection of another fungus Ophiocordyceps sinensis The immune interaction between O. sinensis and the host remains largely unknown, which hinders the artificial cultivation of Chinese cordyceps. We found that T. xiaojinensis ß-1,3-glucan recognition protein-1 (ßGRP1) was needed for prophenoloxidase activation induced by C. militaris Failure of ßGRP1 to recognize O. sinensis is a primary reason for the lack of melanization in the infected host. Lyticase or snailase treatment combined with binding and immunofluorescence detection showed the existence of a protective layer preventing the fungus from ßGRP1 recognition. Coimmunoprecipitation and mass spectrometry analysis indicated that ßGRP1 interacted with immulectin-8 (IML8) via binding to C. militaris IML8 promotes encapsulation. This study suggests the roles of T. xiaojinensis ßGRP1 and IML8 in modulating immune responses against C. militaris Most importantly, the data indicate that O. sinensis may evade melanization by preventing ßGRP1 recognition.

Economic evaluations of chronic obstructive pulmonary disease pharmacotherapy: how well are the real-world issues of medication adherence, comorbidities and adverse drug-reactions addressed?

INTRODUCTION: When estimating the cost-effectiveness or budget impact of chronic obstructive pulmonary disease (COPD) medication, it is common practice to use trial data for clinical inputs. However, such inputs do not always reflect the real-world situation. Previous reviews recognized the need for taking real-world data (medication adherence, comorbidity and adverse drug reactions [ADRs]) into account. Whether recent cost-effectiveness analyses of COPD medication implemented those recommendations is unknown. AREAS COVERED: The authors reviewed recent economic evaluations of COPD-maintenance treatments focusing on medication adherence, comorbidity and ADRs. EXPERT OPINION: In most registration trials of COPD treatment, strict inclusion and exclusion criteria are applied. During trials, patient monitoring is well controlled. As such, medication adherence is often higher than seen in less controlled, real-world environments with more heterogeneous characteristics. Additionally, safety data collected in trials may not be widely generalizable due to more comorbidity and polypharmacy in the real-world. Consequently, when merely relying on trial data, the impact of adherence, comorbidity and ADRs on the cost-effectiveness can be underestimated. To overcome these real-world data gaps, use of pragmatic trials and observational studies in addition to strictly controlled trial data is recommended. To catalyze implementation of these real-world issues, reporting checklists should be updated.

Changes in transcriptomic and metabolomic profiles of morphotypes of Ophiocordyceps sinensis within the hemocoel of its host larvae, Thitarodes xiaojinensis.

BACKGROUND: Ophiocordyceps sinensis (Berk.) is a well-known entomopathogenic and medicinal fungus. It parasitizes and mummifies the underground ghost moth larvae to produce a fruiting body named Chinese cordyceps. Specific for the fungus, O. sinensis experiences a biotrophic vegetative growth period spanning over 5 months. During this vegetative growth, it appears successively in the host hemocoel in three/four morphotypes, namely, the yeast-like blastospores (subdivided into proliferative (BP) and stationary phase (BS)), prehyphae (PreHy) and the hyphae (Hy). This peculiar morphogenesis has been elucidated through morphological and ultrastructural observations, but its molecular basis remains cryptic. In this study, transcriptome and metabolome profiling of BP, BS, PreHy and Hy stages were performed to characterize the key genes, metabolites, and signaling pathways that regulated the vegetative development of O. sinensis in Thitarodes xiaojinensis larva. RESULTS: The molecular events and metabolic pathways that regulated different intracellular processes at various stages were examined. Cluster analyses of differentially expressed genes across the four stages revealed the stage specifically enriched pathways. Analysis of metabolome profiles showed that carbon metabolism and several amino acids biosynthesis were significantly perturbed during the tested development stages of O. sinensis in the host hemocoel. Genes homologous to Saccharomyces cerevisiae MAPK cascade were significantly up-regulated during the transition from blastospore to hypha. The up-regulation of Sho1, a regulator protein, suggested nutrient starvation act a role in activation of MAPK pathway and filamentous growth. In addition, up-regulation of several fatty acid synthesis genes and their corresponding products accumulation in the samples of BS might explain more lipid droplets were observed in BS than in BP. Coupled with the up-regulation of fatty acid degradation during PreHy and Hy stages, it is presumed that lipid accumulation and mobilization play important roles in filamentous development. CONCLUSIONS: This is the first report comprehensively describing developmental transcriptomics and metabolomics of O. sinensis in vivo. Our findings provide new perspectives into the key pathways and hub genes involved in morphological changes of fungus developed in the hemocoel of its host, and are expected to guide future studies on morphogenesis and morphotype changes of entomopathogenic fungi in vivo.

Transcriptomic analysis of the orchestrated molecular mechanisms underlying fruiting body initiation in Chinese cordyceps.

Chinese cordyceps, the fruiting body of the Chinese caterpillar fungus (Ophiocordyceps sinensis, syn. Cordyceps sinensis), is among the most valuable traditional Chinese medicine fungi. Transcriptomic analysis of O. sinensis has revealed several aspects of its life cycle and ecological importance. However, the molecular mechanisms involved in fruiting body initiation remain unclear. The developmental transcriptomes were analyzed from three tissues at the fruiting body initiation stage, namely, the mycelium, sclerotium and primordium. Principal component analysis showed that in the three tissues, the gene expression patterns differed from each other. The functional analysis of differentially expressed genes showed that DNA synthesis and cell division were active in the primordium. In addition, the function of the mycelium was to absorb certain substances from the environment and the sclerotium was the metabolism center of O. sinensis. Genes participating in the mitogen-activated protein kinase (MAPK) signal pathway were involved in fruiting body initiation. Two environmental sensing genes, including a pheromone receptor gene (OSIN6252) and an amino acid sensing gene (OSIN6398), were highly expressed in the primordium, suggesting their important roles in initiation. These results provided insights into the orchestrated functions and gene profiles of different O. sinensis tissues at the key stage. These findings will aid in revealing the underlying mechanisms of fruiting body initiation, which will further benefit artificial cultivation.

A New High-Quality Draft Genome Assembly of the Chinese Cordyceps Ophiocordyceps sinensis.

Ophiocordyceps sinensis (Berk.) is an entomopathogenic fungus endemic to the Qinghai-Tibet Plateau. It parasitizes and mummifies the underground ghost moth larvae, then produces a fruiting body. The fungus-insect complex, called Chinese cordyceps or "DongChongXiaCao," is not only a valuable traditional Chinese medicine, but also a major source of income for numerous Himalayan residents. Here, taking advantage of rapid advances in single-molecule sequencing, we assembled a highly contiguous genome assembly of O. sinensis. The assembly of 23 contigs was ∼110.8 Mb with a N50 length of 18.2 Mb. We used RNA-seq and homologous protein sequences to identify 8,916 protein-coding genes in the IOZ07 assembly. Moreover, 63 secondary metabolite gene clusters were identified in the improved assembly. The improved assembly and genome features described in this study will further inform the evolutionary study and resource utilization of Chinese cordyceps.

Erratum: Wu, B.; et al. Metal-Organic Framework-Based Chemo-Photothermal Combinational System for Precise, Rapid, and Efficient Antibacterial Therapeutics. Pharmaceutics 2019, 11, 463.

The authors wish to make the following corrections to this paper [1]: the hematoxylin and eosin-stained images of kidney in the group of healthy tissue in Figure 8 of this work [1] inadvertently duplicated the kidney results of the PBS group.[...].

Vegetative development and host immune interaction of Ophiocordyceps sinensis within the hemocoel of the ghost moth larva, Thitarodes xiaojinensis.

Ophiocordyceps sinensis is an entomopathogenic fungus that infects ghost moth larva, forming the most valuable and rare traditional Chinese medicine, Chinese cordyceps. Our knowledge of the basic morphology and developmental biology of Chinese cordyceps is limited. In this study, morphological and ultrastructural observations of O. sinensis development in the hemocoel of Thitarodes xiaojinensis were obtained by multiple light and electron microscopy techniques, and the host immune reaction activities were determined. Our results indicated that fungal cells in the host hemocoel underwent morphotype transformations from blastospores to prehyphae to hyphae in sequence. The fusiform yeast-like blastospores were the initial cell type present in the host hemocoel and remained for 5 months or more; the encapsulation reaction and phenoloxidase activity of T. xiaojinensis hemolymph were inhibited during this period. When larvae entered the last instar, the blastospores switched to prehyphae and expanded throughout the host tissues, and then hyphae germinated from the prehyphae and mycelia formed, which finally led to host death. Considering the distinct differences between blastospores and hyphae, we identified prehyphae, which play important roles in fungal expansion, hyphae germination, and fusion formation among filaments. Notably, the elongation of prehyphae was strongly presumed to occur through fission but without separation of the two sister cells, in contrast to blastospore budding. During the morphotype transformation, the amount and composition of lipid droplets changed greatly, suggesting their important roles in these events. Overall, we provide a morphological and ultrastructural characterization of O. sinensis vegetative development within the hemocoel of T. xiaojinensis, identify and name the prehypha fungal cell type in entomopathogenic fungi for the first time, and conclude that O. sinensis infection causes sustained immunosuppression in T. xiaojinensis.

Metal-Organic Framework-Based Chemo-Photothermal Combinational System for Precise, Rapid, and Efficient Antibacterial Therapeutics.

Rapid increase of antimicrobial resistance has become an urgent threat to global public health. In this research, since photothermal therapy is a potential antibacterial strategy, which is less likely to cause resistance, a metal-organic framework-based chemo-photothermal combinational system was constructed. Zeolitic imidazolate frameworks-8 (ZIF-8), a porous carrier with unique features such as high loading and pH-sensitive degradation, was synthesized, and then encapsulated photothermal agent indocyanine green (ICG). First, ICG with improved stability in ZIF-8 (ZIF-8-ICG) can effectively produce heat in response to NIR laser irradiation for precise, rapid, and efficient photothermal bacterial ablation. Meanwhile, Zn2+ ions released from ZIF-8 can inhibit bacterial growth by increasing the permeability of bacterial cell membrane and further strengthen photothermal therapy efficacy by reducing the heat resistance of bacteria. Study showed that bacteria suffered from significant changes in morphology after treatment with ZIF-8-ICG under laser irradiation. The combinational chemo-hyperthermia therapy of ZIF-8-ICG could thoroughly ablate murine subcutaneous abscess induced by methicillin-resistant Staphylococcus aureus (MRSA), exhibiting a nearly 100% bactericidal ratio. Both in vitro and in vivo safety evaluation confirmed that ZIF-8-ICG was low toxic. Overall, our researches demonstrated that ZIF-8-ICG has great potential to be served as an alternative to antibiotics in combating multidrug-resistant bacterial pathogens.

Comparative analysis of C-type lectin domain proteins in the ghost moth, Thitarodes xiaojinensis (Lepidoptera: Hepialidae).

Insects have a large family of C-type lectins involved in cell adhesion, pathogen recognition and activation of immune responses. In this study, 32 transcripts encoding C-type lectin domain proteins (CTLDPs) were identified from the Thitarodes xiaojinensis transcriptome. According to their domain structures, six CTLDPs with one carbohydrate-recognition domain (CRD) were classified into the CTL-S subfamily. The other 23 CTLDPs with two CRDs were grouped into the immulectin (IML) subfamily. The remaining three with extra regulatory domains were sorted into the CTL-X subfamily. Phylogenetic analysis showed that CTL-S and CTL-X members from different insects could form orthologous groups. In contrast, no T. xiaojinensis IML orthologues were found in other insects. Remarkable lineage-specific expansion in this subfamily was observed reflecting that these CTLDPs, as important receptors, have evolved diversified members in response to a variety of microbes. Prediction of binding ligands revealed that T. xiaojinensis, a cold-adapted species, conserved the ability of CRDs to combine with Ca2+ to keep its receptors from freezing. Comparative analysis of induction of CTLDP genes after different immune challenges indicated that IMLs might play critical roles in immune defenses. This study examined T. xiaojinensis CTLDPs and provides a basis for further studies of their characteristics.

Metabolomics reveals the key role of oxygen metabolism in heat susceptibility of an alpine-dwelling ghost moth, Thitarodes xiaojinensis (Lepidoptera: Hepialidae).

Ghost moths inhabiting the alpine meadows of the Tibetan Plateau are cold-adapted stenothermal organisms that are susceptible to heat (dead within 7 days at 27 °C exposure). Exploring the metabolic basis of their heat susceptibility would extend our understanding of the thermal biology of alpine-dwelling invertebrates. Here, gas chromatography-mass spectrometry-based metabolomics was combined with physiological and transcriptional approaches to determine the metabolic mechanisms of heat susceptibility in Thitarodes xiaojinensis larvae. The metabolomics results showed that 27 °C heat stress impaired the Krebs cycle and lipolysis in T. xiaojinensis larvae, as demonstrated by the accumulation of intermediary metabolites. In addition, carbohydrate reserves were highly and exclusively consumed, and an anaerobic product, lactate, accumulated. This evidence suggested a strong reliance on glycolysis to anaerobically generate energy. The respiration rate and enzymatic activity test results indicated a deficiency in O2 metabolism; in addition, the Krebs cycle capacity was not decreased, and the metabolic flux through aerobic pathways was limited. These findings were further supported by the occurrence of hypoxia symptoms in midgut mitochondria (vacuolation and swelling) and increased transcription of hypoxia-induced factor 1-α. Overall, heat stress caused O2 limitation and depressed the overall intensity of aerobic metabolism in ghost moths, and less efficient anaerobic glycolysis was activated to sustain their energy supply. As carbohydrates were depleted, the energy supply became deficient. Our study presents a comprehensive metabolic explanation for the heat susceptibility of ghost moths and reveals the relationship between O2 metabolism and heat susceptibility in these larvae.

Metabolic insights into the cold survival strategy and overwintering of the common cutworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae).

The common cutworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), is a destructive pest in Asia. Although overwintering in the field has not been reported for this species, their larvae are capable of long-term survival in fluctuating temperatures, i.e., 5°C (12h) plus 13°C (12h), if food is available. With an increase in climate change due to global warming and the widespread use of greenhouses, further understanding of their cold survival strategy is needed to predict and control their population in the future. In this study, metabolomics was performed to analyze the metabolic features of S. litura larvae exposed to two typical low temperatures: 15°C and 4°C, at which the development, locomotion and feeding activities are maintained or halted, respectively. The results showed that the strategies that regulate lipid and amino acid metabolism were similar at 15°C and 4°C. Cold exposure induced a metabolic shift of energy from carbohydrate to lipid and decreased free amino acids level. Biosynthesis likely contributed to the decrease in amino acids levels even at 4°C, a non-feeding temperature, suggesting an insufficient suppression of anabolism. This explains why food and high temperature pulses are necessary for their long-term cold survival. Glycometabolism was different between 15°C and 4°C. Carbohydrates were used rapidly at 15°C, while trehalose accumulated at 4°C. Interestingly, abundant trehalose and serine are prominent features of Spodoptera exigua larvae, an overwintering species, when compared to S. litura larvae. Exposure to 4°C also induced up-regulation of carbohydrase and protease in the guts of S. litura. Therefore, it is likely that concurrence of food supplement and fluctuating temperatures could facilitate the cold survival of S. litura larvae. We also found that exposure to 4°C could activate the mevalonate pathway in S. litura larvae, which might be related to glycometabolism at 4°C. Overall, our study describes systematically the responses of a cold susceptible insect, S. litura, to low temperatures and explains how fluctuating temperatures facilitate their long-term cold survival indicating the possibility for overwintering of S. litura larvae with global warming and agricultural reforms.