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1.
Pestic Biochem Physiol ; 200: 105836, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38582598

ABSTRACT

The striped stem borer, Chilo suppressalis (Walker), a notorious pest infesting rice, has evolved a high level of resistance to many commonly used insecticides. In this study, we investigate whether tyrosine hydroxylase (TH), which is required for larval development and cuticle tanning in many insects, could be a potential target for the control of C. suppressalis. We identified and characterized the full-length cDNA (CsTH) of C. suppressalis. The complete open reading frame of CsTH (MW690914) was 1683 bp in length, encoding a protein of 560 amino acids. Within the first to the sixth larval instars, CsTH was high in the first day just after molting, and lower in the ensuing days. From the wandering stage to the adult stage, levels of CSTH began to rise and reached a peak at the pupal stage. These patterns suggested a role for the gene in larval development and larval-pupal cuticle tanning. When we injected dsCsTH or 3-iodotyrosine (3-IT) as a TH inhibitor or fed a larva diet supplemented with 3-IT, there were significant impairments in larval development and larval-pupal cuticle tanning. Adult emergence was severely impaired, and most adults died. These results suggest that CsTH might play a critical role in larval development as well as larval-pupal tanning and immunity in C. suppressalis, and this gene could form a potential novel target for pest control.


Subject(s)
Insecticides , Moths , Oryza , Animals , Larva/genetics , Tyrosine 3-Monooxygenase/genetics , Tyrosine 3-Monooxygenase/metabolism , Pupa , Moths/metabolism , Oryza/metabolism
2.
Front Pharmacol ; 15: 1286422, 2024.
Article in English | MEDLINE | ID: mdl-38420195

ABSTRACT

Objective: To compare the efficacy of a steroid-free regimen with steroid-based treatment in managing primary membranous nephropathy (PMN) and investigate the potential benefits of steroid-free regimens in PMN therapy. Methods: This was a single-centre prospective cohort study. A total of 81 patients were divided into two groups according to their medication regimen: a rituximab (RTX)/tacrolimus (TAC) group (low-dose RTX combined with low-dose TAC group, without steroids, n = 31) and a prednisone (P)/TAC group (P combined with TAC group, n = 61). The changes in 24-h urine protein quantification, levels of blood albumin, blood creatinine, total cholesterol, triglyceride and fasting blood glucose as well as anti-phospholipase A2 receptor antibody titres were observed in both groups before treatment and after 1, 3, 6 and 12 months of treatment. Clinical remission (complete and partial remission), serological remission and recurrence were assessed in both groups after treatment, and the occurrence of adverse reactions was observed. Results: 1) Before treatment, there was no significant difference in baseline values between the two groups (p > 0.05). 2) After 12 months of treatment, the 24-h proteinuria and total cholesterol levels in the RTX/TAC group were significantly lower than those in the P/TAC group (p < 0.05). 3) After 6 months of treatment, the clinical remission rate of the RTX/TAC group was significantly higher than that of the P/TAC group (p < 0.05). After 12 months of treatment, the clinical remission rate of the RTX/TAC group was significantly higher than that of the P/TAC group (p < 0.05). (4) After 3, 6 and 12 months of treatment, serological remission rates in the RTX/TAC group were significantly higher than those in the P/TAC group (p < 0.05). During treatment, the anti-PLA2R antibody titres in the RTX/TAC group remained lower than those in the P/TAC group (p < 0.05). Conclusion: The low-dose RTX combined with low-dose TAC steroid-free regimen induces serological remission in patients with PMN earlier than the classic regimen of P combined with TAC, and there was no significant difference in adverse effects between the two groups. Besides, the long-term clinical remission effect of low-dose RTX combined with low-dose TAC is better than that of P combined with TAC.

3.
J Cancer Res Clin Oncol ; 149(10): 7053-7067, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36862159

ABSTRACT

BACKGROUND: Tumor-associated macrophages (TAMs) constitute the main infiltrating immune cells in the solid tumor microenvironment. Amounting studies have analyzed the antitumor effect on immune response induced by Toll-like receptor (TLR) agonists, such as lipopolysaccharide (LPS), γ-interferon (γ-IFN), and palmitic Acid (PA). However, their combined treatment for gastric cancer (GC) has not been illuminated. METHODS: We investigated the relevance of macrophage polarization and the effect of PA and γ-IFN in GC in vitro and in vivo. M1 and M2 macrophage-associated markers were measured by real-time quantitative PCR and flow cytometry, and the activation level of the TLR4 signaling pathways was evaluated by western blot analysis. The effect of PA and γ-IFN on the proliferation, migration, and invasion of GC cells (GCCs) was evaluated by Cell-Counting Kit-8, transwell assays, and wound-healing assays. In vivo animal models were used to verify the effect of PA and γ-IFN on tumor progression, and the M1 and M2 macrophage markers, CD8 + T lymphocytes, regulatory T cells (Treg) cells, and the myeloid-derived suppressor cells (MDSCs) in tumor tissues were analyzed by flow cytometry and immunohistochemical (IHC). RESULTS: The results showed that this combination strategy enhanced M1-like macrophages and diminished M2-like macrophages through the TLR4 signaling pathway in vitro. In addition, the combination strategy impairs the proliferative and migratory activity of GCC in vitro and in vivo. While, the antitumor effect was abolished using the TAK-424 (a specific TLR-4 signaling pathway inhibitor) in vitro. CONCLUSIONS: The combined treatment of PA and γ-IFN inhibited GC progression by modulating macrophages polarization via the TLR4 pathway.


Subject(s)
Interferon-gamma , Stomach Neoplasms , Animals , Interferon-gamma/metabolism , Stomach Neoplasms/drug therapy , Toll-Like Receptor 4/metabolism , Palmitic Acid/pharmacology , Tumor-Associated Macrophages/metabolism , Cell Line, Tumor , Tumor Microenvironment
4.
Clin Nephrol ; 96(3): 155-164, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33993908

ABSTRACT

OBJECTIVE: To investigate the changes in Treg and Th17 cells and explore the significance of Treg/Th17 balance in adult primary membranous nephropathy (PMN) patients. MATERIALS AND METHODS: A total of 60 PMN patients and 50 healthy adults from June 2013 to October 2016 were enrolled in this study. The levels of Treg, Th17, and related cytokines were assessed. Pearson correlation was used for conducting correlation analysis. RESULTS: There was a significant increase in Th17 frequencies and IL-17 (Th17-related cytokines) in the peripheral blood mononuclear cells (PBMCs), as well as a significant decrease in Treg frequencies and IL-10 (Treg-related cytokines). The IL-17 concentrations in the peripheral blood of PMN patients were positively correlated with urinary protein, while IL-10 levels were negatively correlated with urinary protein. Protein expression of Treg transcription factor (Foxp3) was significantly low in the renal tissues of PMN patients, while the expression of IL-17 was much higher. Th17/Treg imbalance was reversed to normal after effective treatment with tacrolimus in 15 PMN patients. CONCLUSION: These results suggested the existence of Treg/Th17 imbalance in PMN patients, showing the importance of Treg/Th17 imbalance in PMN pathogenesis.


Subject(s)
Glomerulonephritis, Membranous , Th17 Cells , Adult , Cytokines , Forkhead Transcription Factors , Glomerulonephritis, Membranous/diagnosis , Glomerulonephritis, Membranous/drug therapy , Humans , Leukocytes, Mononuclear , T-Lymphocytes, Regulatory
5.
Front Physiol ; 11: 593962, 2020.
Article in English | MEDLINE | ID: mdl-33335488

ABSTRACT

Insect ecdysis triggering hormone (ETH) receptors (ETHRs) are rhodopsin-like G protein-coupled receptors. Upon binding its ligand ETH, ETHR initiates a precisely programed ecdysis behavior series and physiological events. In Drosophila melanogaster, the ethr gene produces two functionally distinct splicing isoforms, ethra and ethrb. ETH/ETHRA activates eclosion hormone (EH), kinin, crustacean cardioactive peptide (CCAP), and bursicon (burs and pburs) neurons, among others, in a rigid order, to elicit the behavioral sequences and physiological actions for ecdysis at all developmental stages, whereas ETH/ETHRB is required at both pupal and adult ecdysis. However, the role of ETHRB in regulation of molting has not been clarified in any non-drosophila insects. In the present paper, we found that 20-hydroxyecdysone (20E) signaling triggers the expression of both ethra and ethrb in a Coleopteran insect pest, the Colorado potato beetle Leptinotarsa decemlineata. RNA interference (RNAi) was performed using double-stranded RNAs (dsRNAs) targeting the common (dsethr) or isoform-specific (dsethra, dsethrb) regions of ethr. RNAi of dsethr, dsethra, or dsethrb by the final-instar larvae arrested larva development. The arrest was not rescued by feeding 20E. All the ethra depleted larvae stopped development at prepupae stage; the body cavity was expanded by a large amount of liquid. Comparably, more than 80% of the ethrb RNAi larvae developmentally halted at the prepupae stage. The remaining Ldethrb hypomorphs became pupae, with blackened wings and highly-expressed burs, pburs and four melanin biosynthesis genes. Therefore, ETHRA and ETHRB play isoform-specific roles in regulation of ecdysis during larva-pupa transition in L. decemlineata.

6.
Gene ; 751: 144779, 2020 Aug 15.
Article in English | MEDLINE | ID: mdl-32428697

ABSTRACT

In insects, nuclear receptors (NRs) including EcR (NR1H1), USP (NR2B4), E75 (NR1D3), HR3 (NR1F), HR4 (NR6) and FTZ-F1 (NR5A3) mediate the 20-hydroxyecdysone (20E) signaling cascade to play a critical role during larval metamorphosis. In this present paper, we focused on hormone receptor 38 (HR38) in Leptinotarsa decemlineata, the only insect homolog of the NR4A subclass. RNA interference (RNAi) of LdHR38 in the penultimate (third) instar larvae reduced the expression of an ecdysteroidogenesis gene and declined the titer of 20E. Knockdown of LdHR38 intensified the expression of LdUSP, LdE75, LdE74, LdE93, LdBroad and LdHR3, whereas repressed the transcription of LdFTZ-F1. Disruption of 20E signaling inhibited chitin biosynthesis in the larval cuticle. Approximately 25% of the LdHR38 RNAi larvae died, around 40% of the resultant larvae remained as prepupae or become deformed pupae. The body surface of the HR38 depleted abnormal prepupae and pupae looked wet, just like the cuticle being covered with a layer of liquid. Moreover, the increase of larval mortality, and the impairment of pupation and emergence exhibited dose-dependent manners. Furthermore, silencing LdHR38 at the final (fourth) instar caused similar but less severe impairment of pupation. Dietary supplement with 20E for the third instar larvae did not rescue the high larval death and only slightly alleviated the low pupation rate in the LdHR38 RNAi hypomorphs. Accordingly, we propose that HR38 is necessary for tune of ecdysteroidogenesis and for mediation of 20E signaling during metamorphosis in L. decemlineata.


Subject(s)
Coleoptera/growth & development , Insect Proteins/physiology , Metamorphosis, Biological , Receptors, Cytoplasmic and Nuclear/physiology , Animals , Chitin/biosynthesis , Coleoptera/genetics , Coleoptera/metabolism , Ecdysterone/physiology , Insect Proteins/antagonists & inhibitors , Insect Proteins/genetics , Larva/genetics , Larva/growth & development , Larva/metabolism , Pupa/genetics , Pupa/growth & development , Pupa/metabolism , RNA Interference , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Receptors, Cytoplasmic and Nuclear/genetics , Signal Transduction
7.
Chin Med J (Engl) ; (6): 699-715, 2020 Mar 20.
Article in English | MEDLINE | ID: mdl-32044818

ABSTRACT

Epigenetic regulation includes changes of DNA methylation and modifications of histone proteins and is essential for normal physiologic functions, especially for controlling gene expression. Epigenetic dysregulation plays a key role in disease pathogenesis and progression of some malignancies, including acute myeloid leukemia (AML). Epigenetic therapies, including hypomethylating agents (HMAs) and histone deacetylase (HDAC) inhibitors, were developed to reprogram the epigenetic abnormalities in AML. However, the molecular mechanisms and therapeutic effects of the two agents alone or their combination remain unknown. An overview of these epigenetic therapies is given here. A literature search was conducted through PubMed database, looking for important biological or clinical studies related to the epigenetic regimens in the treatment of AML until October 15th, 2019. Various types of articles, including original research and reviews, were assessed, identified, and eventually summarized as a collection of data pertaining the mechanisms and clinical effects of HMAs and HDAC inhibitors in AML patients. We provided here an overview of the current understanding of the mechanisms and clinical therapeutic effects involved in the treatment with HMAs and HDAC inhibitors alone, the combination of epigenetic therapies with intensive chemotherapy, and the combination of both types of epigenetic therapies. Relevant clinical trials were also discussed. Generally speaking, the large number of studies and their varied outcomes demonstrate that effects of epigenetic therapies are heterogeneous, and that HMAs combination regimens probably contribute to significant response rates. However, more research is needed to explore therapeutic effects of HDAC inhibitors and various combinations of HMAs and HDAC inhibitors.


Subject(s)
Epigenesis, Genetic/genetics , Histone Deacetylase Inhibitors/therapeutic use , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , DNA Methylation/drug effects , DNA Methylation/genetics , Epigenesis, Genetic/drug effects , Humans
8.
Nat Prod Res ; 34(14): 2080-2085, 2020 Jul.
Article in English | MEDLINE | ID: mdl-30822138

ABSTRACT

A new O-cinnamoyl threonine derivative, O-(2-(3-methyloxiranyl) cinnamoyl) threonine (1), was isolated from the gene adpA overexpression strain Streptomyces sp. HS-NF-1222A. The structure of 1 was determined based on HRESIMS and extensive NMR analysis.


Subject(s)
Bacterial Proteins/genetics , Streptomyces/genetics , Threonine/analogs & derivatives , Trans-Activators/genetics , Gene Expression , Molecular Structure , Spectrum Analysis , Streptomyces/chemistry
9.
Insect Sci ; 27(3): 487-499, 2020 Jun.
Article in English | MEDLINE | ID: mdl-30688001

ABSTRACT

A heterodimer of two nuclear receptors, ecdysone receptor (EcR) and ultraspiracle, mediates 20-hydroxyecdysone (20E) signaling to modulate many aspects in insect life, such as molting and metamorphosis, reproduction, diapause and innate immunity. In the present paper, we intended to determine the isoform-specific roles of EcR during larval-pupal-adult transition in the Colorado potato beetle. Double-stranded RNAs (dsRNAs) were prepared using the common (dsEcR) or isoform-specific (dsEcRA, dsEcRB1) regions of EcR as templates. Ingestion of either dsEcR or dsEcRA, rather than dsEcRB1, by the penultimate (3rd) and final (4th) instar larvae caused failure of larval-pupal and pupal-adult ecdysis. The RNA interference (RNAi) larvae remained as prepupae, or became deformed pupae and adults. Determination of messenger RNA (mRNA) levels of EcR isoforms found that LdEcRA regulates the expression of LdEcRB1. Moreover, silencing the two EcR transcripts, LdEcRA or LdEcRB1 reduced the mRNA levels of Ldspo and Ldsad, and lowered 20E titer. In contrast, the expression levels of HR3, HR4, E74 and E75 were significantly decreased in the LdEcR or LdEcRA RNAi larvae, but not in LdEcRB1 depleted specimens. Dietary supplement with 20E did not restore the expression of five 20E signaling genes (USP, HR3, HR4, E74 and E75), and only partially alleviated the pupation defects in dsEcR- or dsEcRA-fed beetles. These data suggest that EcR plays isoform-specific roles in the regulation of ecdysteroidogenesis and the transduction of 20E signal in L. decemlineata.


Subject(s)
Ecdysterone/metabolism , Metamorphosis, Biological/genetics , Metamorphosis, Biological/physiology , Protein Isoforms/metabolism , Receptors, Steroid/genetics , Animals , Coleoptera/embryology , Insect Proteins/genetics , Insect Proteins/metabolism , Larva/metabolism , Molting/genetics , Protein Isoforms/genetics , Pupa/metabolism , RNA Interference , Receptors, Steroid/metabolism
10.
Pestic Biochem Physiol ; 160: 30-39, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31519255

ABSTRACT

An exploration of novel control strategies for Leptinotarsa decemlineata is becoming more pressing given rapid evolution of insecticide resistance and rise of production loss of potato. Dietary delivery of bacterially expressed double-stranded RNA (dsRNA) is a promising alternative for management. An important first step is to uncover possible RNA-interference (RNAi)-target genes effective against both young and old larvae. Taiman (Tai) is a basic-helix-loop-helix/Per-Arnt-Sim transcription factor that is involved in the mediation of both juvenile hormone (JH) and 20-hydroxyecdysone (20E) signaling. In the present paper, we found that continuous ingestion of dsTai for three days by third (penultimate)-instar larvae caused approximately 20% larval mortality and 80% pupation failure. The larval lethality resulted from failed cuticle and tracheae shedding, which subsequently reduced foliage consumption and nutrient absorption, and depleted lipid stores. In contrast, pupation failure derived from disturbed JH and 20E signals, and disordered nutrient homeostasis including, among others, inhibition of trehalose metabolism and reduction of chitin content. Knockdown of LdTai caused similar larval lethality and pupation impairment in second and fourth (final) larval instars. Therefore, LdTai is among the most attractive candidate genes for RNAi to control L. decemlineata larvae.


Subject(s)
Coleoptera/growth & development , Gene Silencing , Insect Proteins/genetics , Larva/growth & development , Animals , Ecdysterone/metabolism , Gene Knockdown Techniques , Juvenile Hormones/metabolism , RNA Interference
11.
Front Physiol ; 10: 724, 2019.
Article in English | MEDLINE | ID: mdl-31263425

ABSTRACT

Insect Taiman (Tai) binds to methoprene-tolerant to form a heterodimeric complex, mediating juvenile hormone (JH) signaling to regulate larval development and to prevent premature metamorphosis. Tai also acts as a steroid receptor coactivator of 20-hydroxyecdysone (20E) receptor heterodimer, ecdysone receptor (EcR) and Ultraspiracle (USP), to control the differentiation of early germline cells and the migration of specific follicle cells and border cells in ovaries in several insect species. In holometabolous insects, however, whether Tai functions as the coactivator of EcR/USP to transduce 20E message during larval-pupal transition is unknown. In the present paper, we found that the LdTai mRNA levels were positively correlated with circulating JH and 20E titers in Leptinotarsa decemlineata; and ingestion of either JH or 20E stimulated the transcription of LdTai. Moreover, RNA interference (RNAi)-aided knockdown of LdTai at the fourth (final) instar stage repressed both JH and 20E signals, inhibited larval growth and shortened larval developing period. The knockdown caused 100% larval lethality due to failure of larval-pupal ecdysis. Under the apolysed larval cuticle, the LdTai RNAi prepupae possessed pupal thorax. In contrast, the process of tracheal ecdysis was uncompleted. Neither JH nor 20E rescued the aforementioned defectives in LdTai RNAi larvae. It appears that Tai mediates both JH and 20E signaling. Our results uncover a link between JH and 20E pathways during metamorphosis in L. decemlineata.

12.
PLoS Genet ; 15(1): e1007423, 2019 01.
Article in English | MEDLINE | ID: mdl-30615614

ABSTRACT

Many animals exploit several niches sequentially during their life cycles, a fitness referred to as ontogenetic niche shift (ONS). To successfully accomplish ONS, transition between development stages is often coupled with changes in one or more primitive, instinctive behaviors. Yet, the underlining molecular mechanisms remain elusive. We show here that Leptinotarsa decemlineata larvae finish their ONS at the wandering stage by leaving the plant and pupating in soil. At middle wandering phase, larvae also switch their phototactic behavior, from photophilic at foraging period to photophobic. We find that enhancement of juvenile hormone (JH) signal delays the phototactic switch, and vise verse. Moreover, RNA interference (RNAi)-aided knockdown of LdPTTH (prothoracicotropic hormone gene) or LdTorso (PTTH receptor gene) impairs avoidance response to light, a phenotype nonrescuable by 20-hydroxyecdysone. Consequently, the RNAi beetles pupate at the soil surface or in shallow layer of soil, with most of them failing to construct pupation chambers. Furthermore, a combination of depletion of LdPTTH/LdTorso and disturbance of JH signal causes no additive effects on light avoidance response and pupation site selection. Finally, we establish that TrpA1 (transient receptor potential (TRP) cation channel) is necessary for light avoidance behavior, acting downstream of PTTH. We conclude that JH/PTTH cascade concomitantly regulates metamorphosis and the phototaxis switch, to drive ONS of the wandering beetles from plant into soil to start the immobile pupal stage.


Subject(s)
Insect Hormones/genetics , Juvenile Hormones/genetics , Metamorphosis, Biological/genetics , Phototaxis , Animals , Coleoptera/genetics , Coleoptera/growth & development , Ecdysterone/metabolism , Genetic Fitness/genetics , Insect Proteins/genetics , Larva/genetics , Larva/growth & development , Pupa/genetics , Pupa/growth & development , RNA Interference , Signal Transduction
13.
Insect Biochem Mol Biol ; 103: 1-11, 2018 12.
Article in English | MEDLINE | ID: mdl-30296480

ABSTRACT

It is noted that insect insulin/insulin-like growth factor/target of rapamycin signaling is critical for the regulation of metamorphosis in holometabolous insects. However, the molecular mechanism remains undetermined. Our previous findings reveal that RNA interference (RNAi)-mediated knockdown of an insulin gene (LdILP2) in Leptinotarsa decemlineata disturbs both 20-hydroxyecdysone (20E) and juvenile hormone (JH) signaling, and impairs pupation. In the present paper, we further observed that the expression of the insulin receptor substrate gene chico (Ldchico) and the phosphoinositide-3-kinase gene pi3k (Ldpi3k92E) was repressed in LdILP2 depleted larvae. Moreover, RNAi of Ldchico or Ldpi3k92E decreased food consumption, affected absorption and metabolism of amino acids and sugars, and reduced expression of several 20E (LdEcR, LdHR3 and LdE75) and JH (LdJHAMT, LdKr-h1 and LdHairy) signaling genes. As a result, larval development was postponed and larval growth was inhibited. Intriguingly, knockdown of Ldchico, rather than Ldpi3k92E, impaired larval-pupal and pupal-adult ecdysis, and specifically repressed transcription of another 20E signaling gene LdUSP. Ingestion of 20E rescued the expression of LdEcR, LdHR3 and LdE75, whereas 20E feeding restored neither the decreased LdUSP mRNA level, nor the reduced pupation and adult emergence rates in Ldchico RNAi larvae. Therefore, Chico is critical for the regulation of larval-pupal-adult transition by a PI3K-independent pathway, perhaps through activation of USP in L. decemlineata.


Subject(s)
Coleoptera/growth & development , Coleoptera/genetics , Receptor, Insulin/genetics , Animals , Coleoptera/metabolism , Ecdysterone/genetics , Insect Proteins/genetics , Juvenile Hormones/genetics , Larva/genetics , Larva/growth & development , Metamorphosis, Biological/genetics , Phosphatidylinositol 3-Kinase/genetics , RNA Interference
14.
Insect Biochem Mol Biol ; 97: 1-9, 2018 06.
Article in English | MEDLINE | ID: mdl-29680288

ABSTRACT

In the tobacco hornworm Manduca sexta, juvenile hormone (JH) is critical for the control of species-specific size. However, whether the basic helix-loop-helix/Per-Arnt-Sim domain receptor methoprene-tolerant (Met) is involved remains unconfirmed. In the present paper, we found that RNA interference (RNAi)-aided knockdown of Met gene (LdMet) lowered the larval and pupal fresh weights and shortened the larval development period in the Colorado potato beetle Leptinotarsa decemlineata. Dietary introduction of JH into the LdMet RNAi larvae rescued neither the decreased weights nor the reduced development phase, even though JH ingestion by control larvae extended developmental time and caused large pupae. Moreover, the transcript levels of five genes involved in prothoracicotropic hormone and cap 'n' collar isoform C/Kelch-like ECH associated protein 1 pathways were upregulated in the LdMet silenced larvae. Ecdysteroidogenesis was thereby activated; 20-hydroxyecdysone (20E) titer was increased; and 20E signaling pathway was elicited in the LdMet RNAi larvae. Therefore, JH, acting through its receptor Met, inhibits PTTH production and release before the attainment of critical weight. Once the critical weight is reached, JH production and release are averted; and the hemolymph JH is removed. The elimination of JH allows the brain to release PTTH. PTTH subsequently stimulates ecdysteroid biosynthesis and release to start larval-pupal transition in L. decemlineata.


Subject(s)
Body Size/drug effects , Coleoptera/growth & development , Drug Resistance , Ecdysteroids/biosynthesis , Methoprene/pharmacology , Animals , Larva/growth & development
15.
Insect Biochem Mol Biol ; 94: 50-60, 2018 03.
Article in English | MEDLINE | ID: mdl-28951206

ABSTRACT

Hormone receptor 4 (HR4) is involved in the regulation of 20-hydroxyecdysone (20E) biosynthesis and the mediation of 20E signaling during larval-pupal transition in a holometabolan Drosophila melanogaster, whereas it acts as a repressor in 20E-responsive transcriptional cascade in a hemimetabolan, Blattella germanica. Here we characterized two HR4 splicing variants, LdHR4X1 and LdHR4X2, in a coleopteran Leptinotarsa decemlineata. LdHR4X1 was highly expressed in the prothoracic gland and epidermis while LdHR4X2 was abundantly transcribed in the nervous system. In vivo results showed that both prothoracicotropic hormone and 20E pathways transcriptionally regulated LdHR4, in an isoform-dependent pattern. RNA interference of LdHR4 at the final (fourth) larval instar, in contrast to the second- and third-instar periods, enhanced the expression of two ecdysteroidogenesis genes, increased 20E titer, upregulated transcription of five 20E-response genes, and reduced the mRNA level of Fushi tarazu-factor 1 (FTZ-F1). As a result, the fourth-instar LdHR4 RNAi larvae exhibited accelerated development and reduced body weight. Moreover, knockdown of LdHR4 at the fourth instar resulted in larval lethality and impaired pupation. Feeding of pyriproxyfen (a mimic of juvenile hormone) or silencing of a juvenile hormone degrading enzyme gene restored the normal course of ecdysteroidogenesis, duration of larval development, and body weight in fourth-instar LdHR4 RNAi larvae. The treatment partially suppressed the larval mortality but not the failure to pupate. The dual role of HR4 during larval-pupal metamorphosis appears to be evolutionarily conserved among holometabolans.


Subject(s)
Coleoptera/genetics , Ecdysterone/metabolism , Insect Proteins/metabolism , Metamorphosis, Biological/genetics , Animals , Coleoptera/growth & development , Coleoptera/metabolism , Female , Insect Proteins/genetics , Larva/genetics , Larva/growth & development , Larva/metabolism , Male , Molting , Protein Isoforms/genetics , Protein Isoforms/metabolism , Pupa/genetics , Pupa/growth & development , Pupa/metabolism , Sequence Analysis, DNA , Signal Transduction
16.
Pestic Biochem Physiol ; 143: 173-180, 2017 Nov.
Article in English | MEDLINE | ID: mdl-29183589

ABSTRACT

To accomplish consistent, long-term, integrated management (IPM) of the Colorado potato beetle, Leptinotarsa decemlineata (Say), research assessing the potential of novel, IPM-compatible insecticides is essential. Novaluron is a potent benzoylurea insecticide. In the present paper, we found that novaluron ingestion by the fourth-instar larvae inhibited foliage consumption, reduced larval fresh weight, and delayed development period, in a dose dependent manner. Most of the resulting larvae fail to pupate, and died at prepupae stage, with larvicidal activity comparable with those of cyhalothrin and spinosad but lower than those of fipronil and abamectin. Moreover, many surviving pupae that fed novaluron failed to emerge as adults, in a dose dependent pattern. Furthermore, feeding of novaluron significantly decreased chitin contents in body carcass (without midgut) and integument specimen, whereas the chitin concentration in the midgut peritrophic matrix was not affected. Furthermore, uridine diphosphate-N-acetylglucosamine-pyrophosphorylase gene (LdUAP1) and chitin synthase Aa (LdChSAa), which were mainly responsible for chitin biosynthesis in ectodermally-derived tissues, were surpressed and activated respectively after novaluron ingestion. Therefore, novaluron is an effective benzoylurea insecticide to L. decemlineata fourth-instar larvae. It inhibited chitin biosynthesis in ectodermally-derived tissues, disrupted ecdysis, impaired pupation and adult emergence, and led to death in juvenile life stages.


Subject(s)
Chitin/biosynthesis , Coleoptera/drug effects , Insecticides/toxicity , Phenylurea Compounds/toxicity , Animals , Chitin Synthase/metabolism , Coleoptera/metabolism , Eating , Larva/drug effects , Larva/metabolism
17.
Insect Biochem Mol Biol ; 85: 1-10, 2017 06.
Article in English | MEDLINE | ID: mdl-28408149

ABSTRACT

Drosophila cap 'n' collar isoform C (CncC) and Kelch-like ECH associated protein 1 (Keap1) regulate metamorphosis by transcriptional control of a subset of genes involved in ecdysteroidogenesis, 20-hydroxyecdysone (20E) signaling, and juvenile hormone (JH) degradation. In the present paper, we found that prothoracicotropic hormone signal was required for the activation of LdCncC and LdKeap1 in Leptinotarsa decemlineata. Moreover, RNA interference of LdCncC or LdKeap1 in the fourth-instar larvae delayed development. As a result, the treated larvae obtained heavier larval and pupal fresh weights and had larger body sizes than the controls. Furthermore, knockdown of LdCncC or LdKeap1 significantly reduced the mRNA levels of four ecdysone biosynthetic genes (Ldspo, Ldphm, Lddib and Ldsad), lowered 20E titer and decreased the transcript levels of five 20E response genes (LdEcR, LdUSP, LdE75, LdHR3 and LdFTZ-F1). However, the expression of two JH epoxide hydrolase genes and JH contents were not affected in the LdCncC and LdKeap1 RNAi larvae. Dietary supplementation with 20E shortened the developmental period to normal length, rescued the larval and pupal body mass rises, and recovered or even overcompensated the expression levels of the five 20E response genes in either LdCncC or LdKeap1 RNAi hypomorphs. Therefore, LdCncC/LdKeap1 signaling regulates several ecdysteroidogenesis genes, and consequently 20E pulse, to modulate the onset of metamorphosis in L. decemlineata.


Subject(s)
Coleoptera/growth & development , Coleoptera/metabolism , Ecdysteroids/metabolism , Kelch-Like ECH-Associated Protein 1/metabolism , Metamorphosis, Biological , Animals , Coleoptera/genetics , Drosophila Proteins , Ecdysterone/metabolism , Female , Gene Knockdown Techniques , Juvenile Hormones/metabolism , Kelch-Like ECH-Associated Protein 1/genetics , Larva/metabolism , Male , RNA Interference , Repressor Proteins
18.
Insect Biochem Mol Biol ; 77: 52-68, 2016 10.
Article in English | MEDLINE | ID: mdl-27524277

ABSTRACT

Trehalose is proposed to serve multiple physiological roles in insects. However, its importance remains largely unconfirmed. In the present paper, we knocked down either a trehalose biosynthesis gene (trehalose-6-phosphate synthase, LdTPS) or each of three degradation genes (soluble trehalases LdTRE1a, LdTRE1b or membrane-bound LdTRE2) in Leptinotarsa decemlineata by RNA interference (RNAi). Knockdown of LdTPS decreased trehalose content and caused larval and pupal lethality. The LdTPS RNAi survivors consumed a greater amount of foliage, obtained a heavier body mass, accumulated more glycogen, lipid and proline, and had a smaller amount of chitin compared with the controls. Ingestion of trehalose but not glucose rescued the food consumption increase and larval mass rise, increased survivorship, and recovered glycogen, lipid and chitin to the normal levels. In contrast, silencing of LdTRE1a increased trehalose content and resulted in larval and pupal lethality. The surviving LdTRE1a RNAi hypomorphs fed a smaller quantity of food, had a lighter body weight, depleted lipid and several glucogenic amino acids, and contained a smaller amount of chitin. Neither trehalose nor glucose ingestion rescued these LdTRE1a RNAi defects. Silencing of LdTRE1b caused little effects. Knockdown of LdTRE2 caused larval death, increased trehalose contents in several tissues and diminished glycogen in the brain-corpora cardiaca-corpora allata complex (BCC). Feeding glucose but not trehalose partially rescued the high mortality rate and recovered glycogen content in the BCC. It seems that trehalose is involved in feeding regulation, sugar absorption, brain energy supply and chitin biosynthesis in L. decemlineata larvae.


Subject(s)
Coleoptera/genetics , Glucosyltransferases/genetics , RNA Interference , Trehalase/genetics , Trehalose/genetics , Animals , Coleoptera/growth & development , Coleoptera/metabolism , Female , Glucosyltransferases/metabolism , Larva/genetics , Larva/growth & development , Larva/metabolism , Male , Pupa/genetics , Pupa/growth & development , Pupa/metabolism , Trehalase/metabolism , Trehalose/metabolism
19.
J Ethnopharmacol ; 161: 214-23, 2015 Feb 23.
Article in English | MEDLINE | ID: mdl-25523372

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Fresh Portulaca oleracea L. (family: Portulacaceae; POL) has been used as a folk medicine for the treatment of diabetes mellitus for a long time. More bioactive components with higher activity could be retained in fresh medicinal herbs compared to the dried ones. The present study was conducted to compare different antidiabetic activity between fresh and dried POL, including hypoglycemic and antioxidant activities both in vivo and in vitro. Furthermore, in order to explore which components were responsible for the antidiabetic activity, the difference on chemical components between fresh and dried POL was analyzed and compared. MATERIALS AND METHODS: Insulin-resistant HepG2 cells induced by insulin were used to evaluate the promoting effect of the fresh and dried POL on glucose utilization in vitro. Streptozotocin (STZ)-induced C57BL/6J diabetic mice were used to compare the differences on hypoglycemic and antioxidant activities of fresh and dried POL, including the fasting blood glucose, glucose tolerance, serum insulin level, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in vivo. UPLC/Q-TOF-MS method was performed to analyze the difference of antidiabetic components between fresh and dried POL. RESULTS: Compared with the dried POL extract, the fresh POL extract significantly increased the consumption of extracellular glucose in insulin-resistant HepG2 cells (P<0.05). In STZ-induced C57BL/6J diabetic mice, both fresh and dried extracts decreased markedly the fasting blood glucose (FBG) levels, and improved significantly oral glucose tolerance test (OGTT), as well as enhanced significantly insulin secretion and antioxidative activities (P<0.05; P<0.01). Furthermore, the fresh extract showed stronger antidiabetic activity (P<0.05). The UPLC/Q-TOF-MS analysis results also revealed that the relative contents of polyphenols and alkaloids in the fresh herbs were more abundant than those in the dried POL. CONCLUSION: Our results indicated that both fresh and dried POL possessed antidiabetic activities, besides stronger activity was observed in the fresh herb. These findings provided evidence for the application and development of fresh POL in the treatment of diabetes mellitus.


Subject(s)
Antioxidants/therapeutic use , Diabetes Mellitus, Experimental/drug therapy , Hypoglycemic Agents/therapeutic use , Phytotherapy , Plant Extracts/therapeutic use , Portulaca , Animals , Antioxidants/pharmacology , Blood Glucose/analysis , Cell Survival/drug effects , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/metabolism , Hep G2 Cells , Humans , Hypoglycemic Agents/pharmacology , Insulin/blood , Insulin Resistance , Liver/drug effects , Liver/metabolism , Male , Malondialdehyde/metabolism , Mice, Inbred C57BL , Plant Extracts/pharmacology , Superoxide Dismutase/metabolism
20.
Curr Ther Res Clin Exp ; 74: 22-5, 2013 Jun.
Article in English | MEDLINE | ID: mdl-24384611

ABSTRACT

OBJECTIVE: To survey the clinical epidemiology and correlations between pathology and clinical features of major groups of kidney diseases in a rural area of China. METHODS: From January 1996 to December 2010, histologic diagnosis of renal disease was made on samples collected from 919 patients from a single center in the midland rural area of China. Demographic data were obtained from all patients, and clinical profiles were analyzed in 917 patients. RESULTS: The mean age of the whole group was 33.13 (14.13) years (range 16-72 years). Men accounted for 55.28% (n = 508) and women made up 45.72% (n = 408). Patients aged 16 to 50 years comprised 83.75% of the sample (n = 770). Lupus nephritis was the predominant diagnosis in women; renal diseases were predominant in men. In patients with nephrotic syndrome, mesangial proliferative glomerulonephritis was the most frequent pathologic pattern (39.46%), followed by IgA nephropathy (18.39%), whereas in patients with nephritic syndrome, IgA nephropathy (39.64%) was the most frequent pathologic pattern, followed by mesangial proliferative glomerulonephritis (32.38%). The most common pathologic pattern in patients with secondary glomerulonephritis was Henoch-Schoˇnlein purpura nephritis, followed by lupus nephritis. CONCLUSIONS: Mesangial proliferative glomerulonephritis was the most common renal pathologic pattern. Male adolescents were predominant in this group of patients. The most common clinical syndrome was nephrotic syndrome.

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