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1.
Angew Chem Int Ed Engl ; : e202404244, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38639067

ABSTRACT

Ratiometric afterglow luminescent (AGL) probes are attractive for in vivo imaging due to their high sensitivity and signal self-calibration function. However, there are currently few ratiometric AGL probes available for imaging enzymatic activity in living organisms. Here, we present an energy diversion (ED) strategy that enables the design of an enzyme-activated ratiometric AGL probe (RAG-RGD) for in vivo afterglow imaging. The ED process provides RAG-RGD with a radiative transition for an 'always on' 520-nm AGL signal (AGL520) and a cascade three-step energy transfer (ET) process for an 'off-on' 710-nm AGL signal (AGL710) in response to a specific enzyme. Using matrix metalloproteinase-2 (MMP-2) as an example, RAG-RGD shows a significant ~11-fold increase in AGL710/AGL520 toward MMP-2. This can sensitively detect U87MG brain tumors through ratiometric afterglow imaging of MMP-2 activity, with a high signal-to-background ratio and deep imaging depth. Furthermore, by utilizing the self-calibration effect of ratiometric imaging, RAG-RGD demonstrated a strong negative correlation between the AGL710/AGL520 value and the size of orthotopic U87MG tumor, enabling accurate monitoring of orthotopic glioma growth in vivo. This ED process may be applied for the design of other enzyme-activated ratiometric afterglow probes for sensitive afterglow imaging.

3.
Cancer Med ; 13(3): e7016, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38400675

ABSTRACT

PURPOSE: The study aimed to retrospectively identify the prognostic factors of surgically treated primary tongue squamous cell carcinoma (TSCC) cases and assess the benefits of surgical neck lymph node dissection (LND) in early-stage cancer. METHODS: Patients with primary TSCC with pT1-2N0-1M0 stage without distant metastasis who were treated with surgery during 2014-2016 at Xiangya Hospital, Central South University were included. Univariate and multivariate Cox models were constructed to explore prognostic factors of overall survival (OS), disease-free survival (DFS), and local recurrence-free survival (LRFS). Sub-group analysis was used to assess the effect of adjuvant therapy and the prognostic value of LND for the early-stage patients. RESULTS: In total, 440 patients met the inclusion criteria. During the follow-up period, the 5-year OS, DFS, were 84.4% and 70.0%, respectively. Univariate analysis showed that TNM stage, lymphovascular invasion (LVI), and/or perineural invasion (PNI), pathological differentiation, etc. were significant predictors of OS and DFS. Multivariate analysis showed that TNM stage and the degree of pathological differentiation were independent prognostic factors for all outcomes. Besides, the number of cervical LND could independently predict both DFS and LRFS while LVI/PNI were associated with DFS. And high-quality neck LND (≥30) significantly improved DFS and LRFS for patients of pT1cN0M0 or stage I as compared to those without LND. CONCLUSIONS: TNM stage and pathological differentiation were crucial prognostic factors for postoperative patients with TSCC. Notably, high-quality cervical LND was beneficial for the improvement of DFS and LRFS for patients of pT1cN0M0 or stage I.


Subject(s)
Carcinoma, Squamous Cell , Tongue Neoplasms , Humans , Carcinoma, Squamous Cell/surgery , Carcinoma, Squamous Cell/pathology , Prognosis , Tongue Neoplasms/surgery , Tongue Neoplasms/pathology , Retrospective Studies , Neoplasm Staging , Tongue
4.
Pest Manag Sci ; 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38358092

ABSTRACT

BACKGROUND: Detoxifying enzymes are likely involved in lignin feeding and immune defense mechanisms within termites, rendering them potential targets for biological control. However, investigations into the dual functionality of termite detoxification enzymes in vivo have not been documented. RESULTS: In this study, the complete cDNA of the catalase gene (Cfcat) derived from Coptotermes formosanus Shiraki was amplified. CFCAT comprises an open reading frame spanning 1527 bp, encoding a 508-amino acid sequence. The highest expression was observed in the epidermal tissues (including the fat body and hemolymph) followed by the foregut/salivary gland. Furthermore, we confirmed the catalase activity of the recombinant Cfcat protein. Using RNA interference (RNAi) technology, the importance of Cfcat in the lignin-feeding of C. formosanus was demonstrated, and the role of Cfcat in innate immunity was investigated. Survival assays showed that Cfcat RNAi significantly increased the susceptibility of C. formosanus to Metarhizium anisopliae. Irrespective of the infection status, Cfcat inhibition had a significant impact on multiple factors of humoral and intestinal immunity in C. formosanus. Notably, Cfcat RNAi exhibited a more pronounced immunosuppressive effect on humoral immunity than on intestinal immunity. CONCLUSION: Cfcat plays an important role in the regulation of innate immunity and lignin feeding in C. formosanus. Cfcat RNAi can weaken the immune response of termites against M. anisopliae, which may aid the biocontrol efficiency of M. anisopliae against C. formosanus. This study provides a theoretical basis and technical reference for the development of a novel biocontrol strategy targeting detoxifying enzymes of termites. © 2024 Society of Chemical Industry.

6.
Angew Chem Int Ed Engl ; 63(4): e202314039, 2024 Jan 22.
Article in English | MEDLINE | ID: mdl-38055211

ABSTRACT

We report here a tumor-pretargted theranostic approach for multimodality imaging-guided synergistic cancer PDT by cascade alkaline phosphatase (ALP)-mediated in situ self-assembly and bioorthogonal inverse electron demand Diels-Alder (IEDDA) reaction. Using the enzymatic catalysis of ALP that continuously catalyses the dephosphorylation and self-assembly of trans-cyclooctene (TCO)-bearing P-FFGd-TCO, a high density of fluorescent and magnetic TCO-containing nanoparticles (FMNPs-TCO) can be synthesized and retained on the membrane of tumor cells. They can act as 'artificial antigens' amenable to concurrently capture lately administrated tetrazine (Tz)-decorated PS (775NP-Tz) and carbonic anhydrase (CA) inhibitor (SA-Tz) via the fast IEDDA reaction. This two-step pretargeting process can further induce FMNPs-TCO regrowth into microparticles (FMNPs-775/SA) directly on tumor cell membranes, which is analyzed by bio-SEM and fluorescence imaging. Thus, efficient enrichment of both SA-Tz and 775NP-Tz in tumors can be achieved, allowing to alleviate hypoxia by continuously inhibiting CA activity and improving PDT of tumors. Findings show that subcutaneous HeLa tumors could be completely eradicated and no tumor recurred after irradiation with an 808 nm laser (0.33 W cm-2 , 10 min). This pretargeted approach may be applied to enrich other therapeutic agents in tumors to improve targeted therapy.


Subject(s)
Neoplasms , Photosensitizing Agents , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Carbonic Anhydrase Inhibitors/pharmacology , Radiopharmaceuticals , Precision Medicine , Cell Line, Tumor , Cycloaddition Reaction , Cyclooctanes , Neoplasms/diagnostic imaging , Neoplasms/drug therapy
7.
J Am Chem Soc ; 145(50): 27838-27849, 2023 12 20.
Article in English | MEDLINE | ID: mdl-38059465

ABSTRACT

Hydrogen sulfide (H2S) has shown promise for gas therapy. However, it is still controversial whether H2S can remodel the tumor microenvironment (TME) and induce robust antitumor immunity. Here, a tumor-targeting and TME-responsive "smart" lipid nanoparticle (1-JK-PS-FA) is presented, which is capable of delivering and releasing H2S specifically in tumor tissues for on-demand H2S gas and photodynamic immunotherapy. 1-JK-PS-FA enables a burst release of H2S in the acidic TME, which promptly reduces the embedded organic electrochromic materials and consequently switches on near-infrared fluorescence and photodynamic activity. Furthermore, we found that high levels of H2S can reprogram the TME by reducing tumor interstitial fluid pressure, promoting angiogenesis, increasing vascular permeability, ameliorating hypoxia, and reducing immunosuppressive conditions. This leads to increased tumor uptake of 1-JK-PS-FA, thereby enhancing PDT efficacy and eliciting strong immunogenic cell death during 808 nm laser irradiation. Therefore, 1-JK-PS-FA permits synergistic H2S gas and photodynamic immunotherapy, effectively eradicating orthotopic breast tumors and preventing tumor metastasis and recurrence. This work showcases the capacity of H2S to reprogram the TME to enhance H2S gas and immunotherapy.


Subject(s)
Mammary Neoplasms, Animal , Nanoparticles , Neoplasms , Photochemotherapy , Animals , Tumor Microenvironment , Immunotherapy , Biological Transport , Cell Line, Tumor
8.
Pak J Med Sci ; 39(6): 1774-1778, 2023.
Article in English | MEDLINE | ID: mdl-37936771

ABSTRACT

Objective: To investigate the analgesic effect of thoracic paravertebral block (TPVB) in patients undergoing thoracoscopic lobectomy under general anesthesia (GA). Methods: Clinical records of 82 patients who underwent thoracoscopic lobectomy under GA from October 2021 to October 2022 in the General Hospital of Southern Theater Command were retrospectively analyzed. The patients were divided into two groups according to the method of anesthesia used: general anesthesia group (Group-G, n=37), and TPVB plus GA group (Group-T, n=45). The analgesic effect, mean arterial pressure (MAP), heart rate (HR) and the rate of adverse events in both groups were compared. Results: Visual analogue scale (VAS) scores of patients in Group-T at 12h, 24h and 48h after the operation were significantly lower compared to Group-G (P<0.05). MAP and HR the time of tracheal intubation induction (T1), single lung ventilation (T2), skin incision (T3), operation completion (T4), and 20 minutes after the extubation (T5) were lower in both groups compared to T0, and were significantly higher in Group-T compared to Group-G (P<0.05). The rate of adverse events in Group-T was 6.67%, significantly lower compared to Group-G (24.32%) (P<0.05). Conclusions: TPVB combined with GA can improve the analgesic effect, improve MAP and HR during the operation, and reduce the incidence of adverse events in patients undergoing thoracoscopic lobectomy.

9.
Pestic Biochem Physiol ; 196: 105621, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37945257

ABSTRACT

Biocontrol of subterranean termites is largely impeded by their social immune responses. Studies on biocontrol agents combined with natural insecticides and their possible effects on the immune defense mechanisms of termites are limited. In this study, we investigated the effects of a combined biocontrol strategy using a plant-derived insect ATPase inhibitor, α-terpineol, with the entomopathogenic nematodes (EPNs) Steinernema carpocapsae against the subterranean termite Coptotermes formosanus Shiraki. Survival assays showed that even a low lethal concentration of α-terpineol significantly increased the EPNs-induced virulence in C. formosanus. α-terpineol treatment majorly inhibited the activity of Na+- K+- ATPase, which disturbed the EPNs-induced enhancement of locomotor activity and grooming behavior in termites treated with the combined strategy. Furthermore, the combination treatment had a synergistic inhibitory effect on innate immune responses in C. formosanus, which were measured as changes in the expression of immune-related genes and activities of immune system enzymes. In conclusion, α-terpineol can weaken the immune defense of termites against EPNs at low lethal concentrations, and is a suitable non-synthetic insecticide to prove the biocontrol efficiency of EPNs on C. formosanus. This study provides a theoretical basis and technical reference for a novel biocontrol strategy that promises to overcome the problems of host immune defense in termites.


Subject(s)
Insecticides , Isoptera , Nematoda , Animals , Isoptera/physiology , Virulence , Insecticides/pharmacology , Adenosine Triphosphatases
10.
Int Immunopharmacol ; 123: 110727, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37597402

ABSTRACT

OBJECTIVE: Acute lung injury (ALI) is featured as excessive inflammatory response and oxidative damage, and results in high death rate of septic patients. This research intends to determine the function of multiple EGF like domains 6 (MEGF6) in sepsis-induced ALI. METHODS: Mice were intratracheally treated with adenovirus to knock down or overexpress MEGF6 in lung tissues, and then were subjected to cecum ligation and puncture (CLP) operation to induce ALI. Primary peritoneal macrophages were isolated, and were knocked down or overexpressed with MEGF6, and then, were stimulated with lipopolysaccharide (LPS) to confirm its role in vitro. RESULTS: Serum and lung MEGF6 levels were significantly elevated in septic mice. MEGF6 knockdown exacerbated, while MEGF6 overexpression prevented inflammation, oxidative damage and ALI in CLP mice. Meanwhile, LPS-elicited inflammatory response and oxidative damage in primary macrophages were reduced by MEGF6 overexpression, but were further aggravated by MEGF6 knockdown. Mechanistic studies revealed that MEGF6 reduced cluster of differentiation 38 (CD38) expression and subsequently elevated intracellular nicotinamide adenine dinucleotide levels, thereby activating sirtuin 1 (SIRT1) without affecting the protein expression. SIRT1 suppression or CD38 overexpression with either genetic or pharmacologic methods remarkably blunted the lung protective effects of MEGF6 in CLP mice. CONCLUSION: MEGF6 prevents CLP-induced ALI through CD38/SIRT1 pathway, and it might be a valuable therapeutic candidate for the management of sepsis-induced ALI.


Subject(s)
Acute Lung Injury , Sepsis , Animals , Humans , Mice , Acute Lung Injury/drug therapy , Acute Lung Injury/etiology , ADP-ribosyl Cyclase 1 , Lipopolysaccharides , Sepsis/complications , Sirtuin 1
11.
Gene ; 877: 147569, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-37330022

ABSTRACT

In recent years, the use of microbes to control termites has attracted increasing attention. It was found that pathogenic bacteria, nematodes, and fungi effectively control termites under laboratory conditions. However, their effects have not been replicated in the field, and one reason for this is the complex immune defense mechanisms of termites, which are mainly regulated by immune genes. Therefore, altering the expression of immune genes may have a positive influence on the biocontrol efficacy of termites. Coptotermes formosanus Shiraki is one of the most economically important termite pests worldwide. Currently, the large-scale identification of immune genes in C. formosanus is primarily based on cDNA library or transcriptome data rather than at the genomic level. In this study, we identified the immune genes of C. formosanus according to genome-wide analysis. In addition, our transcriptome analysis showed that immune genes were significantly downregulated when C. formosanus was exposed to the fungus Metarhizium anisopliae or nematodes. Finally, we found that injecting dsRNA to inhibit three immune genes (CfPGRP-SC1, CfSCRB3, and CfHemocytin), which recognize infectious microbes, significantly increased the lethal effect of M. anisopliae on termites. These immune genes show great potential for C. formosanus management based on RNAi. These results also increase the number of known immune genes in C. formosanus which will provide a more comprehensive insight into the molecular basis of immunity in termites.


Subject(s)
Isoptera , Metarhizium , Animals , Isoptera/genetics , Isoptera/microbiology , Metarhizium/genetics , Gene Expression Profiling
12.
Pest Manag Sci ; 79(7): 2299-2310, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36775842

ABSTRACT

BACKGROUND: RNA interference (RNAi) technology is an environmentally friendly strategy for controlling insect pests. Lipopolysaccharide-binding protein (LBP) recognizes lipopolysaccharides, which are a major outer membrane constituent of Gram-negative bacteria. We propose that the LBP gene is a potential target for termite management; however, to date, no studies have examined this gene in termites. RESULTS: In this study, we cloned the LBP gene of Coptotermes formosanus (Cf) and found that the mortality rate of termite workers significantly increased, and the repellence of these workers to Gram-negative bacteria was suppressed after knockdown of CfLBP using double-stranded RNA (dsRNA) injection and feeding. Moreover, the mortality rate of termite workers fed with CfLBP dsRNA and three Gram-negative bacteria (provided separately) was over 50%, which was much higher than that of termites treated with either CfLBP dsRNA or Gram-negative bacteria. Finally, we found that CfLBP impacts the IMD pathway to regulate the immune response of C. formosanus to Gram-negative bacteria. CONCLUSION: CfLBP plays a important role in the immune defense of termites against Gram-negative bacteria. It can be used as an immunosuppressant for RNAi-based termite management and is an ideal target for termite control based on the combined use of RNAi and pathogenic bacteria. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Subject(s)
Isoptera , Animals , Isoptera/genetics , RNA, Double-Stranded/genetics , Pest Control , Gram-Negative Bacteria
13.
Angew Chem Int Ed Engl ; 62(10): e202217055, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36602292

ABSTRACT

Tumor-targeted and stimuli-activatable nanosensitizers are highly desirable for cancer theranostics. However, designing smart nanosensitizers with multiple imaging signals and synergistic therapeutic activities switched on is challenging. Herein, we report tumor-targeted and redox-activatable nanosensitizers (1-NPs) for sono-photodynamic immunotherapy of tumors by molecular co-assembly and redox-controlled disassembly. 1-NPs show a high longitudinal relaxivity (r1 =18.7±0.3 mM-1 s-1 ), but "off" dual fluorescence (FL) emission (at 547 and 672 nm), "off" sono-photodynamic therapy and indoleamine 2,3-dioxygenase 1 (IDO1) inhibition activities. Upon reduction by glutathione (GSH), 1-NPs rapidly disassemble and remotely release small molecules 2-Gd, Zn-PPA-SH and NLG919, concurrently switching on (1) dual FL emission, (2) sono-photodynamic therapy and (3) IDO1 inhibition activities. After systemic injection, 1-NPs are effective for bimodal FL and magnetic resonance (MR) imaging-guided sono-photodynamic immunotherapy of orthotropic breast and brain tumors in mice under combined ultrasound (US) and 671-nm laser irradiation.


Subject(s)
Nanoparticles , Neoplasms , Photochemotherapy , Animals , Mice , Photochemotherapy/methods , Neoplasms/drug therapy , Fluorescence , Oxidation-Reduction , Immunotherapy , Cell Line, Tumor , Photosensitizing Agents/therapeutic use
14.
Nat Biomed Eng ; 7(3): 197-198, 2023 03.
Article in English | MEDLINE | ID: mdl-36550301
15.
Insect Sci ; 30(1): 185-196, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35567495

ABSTRACT

Termites have physiological and behavioral immunities that make them highly resistant to pathogen infections, which complicates biocontrol efforts. However, the stimuli that trigger the pathogen-avoidance behaviors of termites are still unclear. Our study shows that workers of Coptotermes formosanus exposed to the conidia of Metarhizium anisopliae exhibited a significantly higher frequency and longer duration of allogrooming behaviors compared with untreated termites. Volatile compounds in the cuticle of control termites and termites previously exposed to a suspension of M. anisopliae conidia were analyzed and compared using a gas chromatography-mass spectrometer (GC-MS). Our results showed that the amount of ergosterol differed between the fungus-exposed and control termites. Choice tests showed that termites significantly preferred to stay on filter paper treated with ergosterol (0.05, 0.1, or 1.0 mg/mL) compared with control filter paper. In addition, termites exposed to ergosterol followed by M. anisopliae conidia were allogroomed at a significantly higher frequency and for a longer duration than termites exposed to alcohol (the solvent used with the ergosterol in the ergosterol trials) alone followed by M. anisopliae conidia. These results showed that ergosterol may enhance the allogrooming behavior of termites in the presence of entomopathogenic fungi.


Subject(s)
Isoptera , Metarhizium , Animals , Metarhizium/physiology , Isoptera/physiology , Behavior, Animal , Spores, Fungal
16.
Ann Transl Med ; 10(21): 1153, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36467357

ABSTRACT

Background: Diffuse pulmonary vein stenosis (PVS) is an intractable congenital heart disease for which the underlying mechanism remains unclear. In this study, we investigated the effect of losartan and the role of the Hippo pathway in PVS. Methods: A total of 19 neonatal piglets were divided into 3 groups: a sham group (n=7), a banded group (n=6) with the left upper pulmonary vein and common trunk of both lower pulmonary veins banded, and a losartan group (n=6) with losartan treatment (1 mg/kg/d) after the banding operation. After 8 weeks, the piglets underwent hemodynamic measurement and harvesting. The upstream pulmonary veins were collected for histological staining and molecular biological analysis. Losartan and/or angiotensin II (stepwise concentrations from 0.1 to 100 µmol/L) were added to a human umbilical vein endothelial cell culture to investigate the potential mechanism in vitro. Results: The modified model demonstrated the main characteristics of patients with PVS, including pulmonary hypertension and intimal hyperplasia in the upstream veins. Upregulation of yes-associated protein (YAP) and angiotensin II type 1 receptor was observed in the neointima (P<0.01). Losartan treatment improved the pathological changes in piglets and decreased YAP expression in the neointima (P<0.01). In vitro, losartan suppressed angiotensin II-induced cell proliferation by inhibiting dephosphorylation and nuclear translocation of YAP in human umbilical vein endothelial cells (P<0.05). Conclusions: Losartan treatment ameliorates intimal hyperplasia and inhibits YAP activation. The activation of the Hippo-YAP pathway is involved in the vasculopathy of progressive PVS. These findings may contribute to the development of new approaches for treating PVS.

17.
Chemistry ; 28(70): e202202457, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-36109342

ABSTRACT

10,11-Bis[bis(4-dimethylaminophenyl)methylene]dibenzo[bf]thiepin (1) and -oxepin (2) were prepared as stable yellow crystalline compounds, which are the cyclic analogues of electron-donating hexaarylbutadienes. Upon two-electron oxidation, they are reversibly transformed into the title dications (12+ and 22+ ) exhibiting near-infrared (NIR) absorptions, which were also isolated as stable salts. These redox pairs can serve as new entries into less well-explored organic NIR-electrochromic systems, and the separation of redox peaks (electrochemical bistability) was attained for 1/12+ and 2/22+ , thanks to drastic geometrical changes between neutral and dicationic states, as revealed by a series of X-ray analyses. Thiepin-S,S-dioxide analogue (3/32+ ) exhibits quite similar dynamic redox behavior due to nonaromatic nature of the dibenzothiepin and -oxepin unit in 12+ and 22+ , whereas the thiepin-S-oxide derivative (4/42+ ) does not exhibit bistability due to the smaller change in geometry upon electron transfer, showing that a subtle change of a bridging atom in the central seven-membered ring can modify the redox properties.

18.
Angew Chem Int Ed Engl ; 61(37): e202209248, 2022 09 12.
Article in English | MEDLINE | ID: mdl-35851521

ABSTRACT

Reversible imaging probes that allow for the dynamic visualization of the redox cycle between hydroxyl radical (⋅OH) and hydrogen sulfide (H2 S) are vital to probe the redox imbalance-involved pathological process in vivo. Herein, we report a reversible ratiometric photoacoustic (PA) imaging nanoprobe (1-PAIN) for the real-time imaging of ⋅OH/H2 S redox cycle in vivo. 1-PAIN displays a low PA ratio between 690 and 825 nm (PA690 /PA825 ), which significantly increases by ≈5-fold upon oxidation by ⋅OH, and is switched back to the initially low PA690 /PA825 value upon reduction by H2 S. 1-PAIN could dynamically report on the hepatic ⋅OH production in mice during the lipopolysaccharide (LPS)-induced liver inflammation process, and visualize hepatic H2 S generation during the N-acetyl cysteine (NAC)-induced anti-inflammation process. 1-PAIN can act as a useful tool to probe the redox state in living biology, beneficial for the study of redox imbalance-related diseases.


Subject(s)
Hydrogen Sulfide , Photoacoustic Techniques , Animals , Fluorescent Dyes , Hydroxyl Radical , Liver/diagnostic imaging , Mice , Oxidation-Reduction , Photoacoustic Techniques/methods , Spectrum Analysis
19.
Front Physiol ; 13: 906235, 2022.
Article in English | MEDLINE | ID: mdl-35733990

ABSTRACT

Termites possess a mighty social immune system, serving as one of the key obstacles to controlling them biologically. However, the dynamic mechanism coordinating the social immunologic defense and caste distribution of the termites remains elusive. This study used the Coptotermes formosanus Shiraki and an entomopathogenic fungus as a host-pathogen system and experimentally manipulated a series of groups with different caste compositions of workers and soldiers. Then, the impact of demography on the behavior and innate immunity of termites was explored by analyzing the fungus susceptibility of the respective caste, efficiencies, and caste preferences of sanitary care, as well as the expression of the immune genes and phenoloxidase activity. Overall, to ensure the general health and survival of a group, the infected workers were found to sacrifice their survivorship for maintaining the soldier proportion of the group. If soldier proportion was limited within a threshold, both the survivorship of the workers and soldiers were not significantly affected by the infection. Correspondingly, the infected group with a higher proportion of soldiers stimulated the higher efficiency of a non-caste-biased sanitary care of the workers to the nestmate workers and soldiers. Moreover, the innate immunities of the infected workers were found to be more intensely upregulated in the group with higher soldier proportions. This suggested that the adjustable non-caste-biased sanitary care and innate immunity of the workers would contribute to the flexibility of the worker-soldier caste ratio in C. formosanus. This study, therefore, enhanced our understanding of the functional adaptation mechanism between pathogen-driven social immunity and the demography of the termites.

20.
BMC Ecol Evol ; 22(1): 80, 2022 06 21.
Article in English | MEDLINE | ID: mdl-35729504

ABSTRACT

BACKGROUND: The ecology and evolution of phoretic mites and termites have not been well studied. In particular, it is unknown whether the specific relationship between mites and termites is commensal or parasitic. High phoretic mite densities have often been found to occur in weak termite colonies, suggesting that the relationship is closer to that of parasitism than commensalism. RESULTS: To examine this, Coptotermes formosanus was used as a carrier, and Acarus farris as the phoretic mite. We used video recordings to observe termite social immunity behaviors and bioassay to examine termite fitness. Our results showed that the attachment of the mite on the termite can enhance termite social immunity behaviors like alarm vibration and grooming frequency while decreasing the duration of individual grooming episodes in phoretic mites. Further, A. farris phoresy led to a 22.91% reduction in termite abdomen volume and a 3.31-fold increase in termite mortality. CONCLUSIONS: When termites groom more frequently, the consequence is short duration of grooming bouts. This may be indicative of a trade-off which provides suggestive evidence that frequent social behaviors may cost termites energy. And this caused phoretic behavior hastened termites' death, and helped propagate the population of mites feeding on dead termites. So, it provides a case for phoresy being a precursor to parasitism, and the specific relationship between A. farris and C. formosanus is closer to parasitism than to commensalism.


Subject(s)
Isoptera , Mites , Animals , Grooming , Social Behavior , Symbiosis
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