Drosophila eIF3f1 mediates host immune defense by targeting dTak1.

Eukaryotic translation initiation factors have long been recognized for their critical roles in governing the translation of coding RNAs into peptides/proteins. However, whether they harbor functional activities at the post-translational level remains poorly understood. Here, we demonstrate that eIF3f1 (eukaryotic translation initiation factor 3 subunit f1), which encodes an archetypal deubiquitinase, is essential for the antimicrobial innate immune defense of Drosophila melanogaster. Our in vitro and in vivo evidence indicate that the immunological function of eIF3f1 is dependent on the N-terminal JAMM (JAB1/MPN/Mov34 metalloenzymes) domain. Mechanistically, eIF3f1 physically associates with dTak1 (Drosophila TGF-beta activating kinase 1), a key regulator of the IMD (immune deficiency) signaling pathway, and mediates the turnover of dTak1 by specifically restricting its K48-linked ubiquitination. Collectively, these results provide compelling insight into a noncanonical molecular function of a translation initiation factor that controls the post-translational modification of a target protein.

E3 ligase Cul2 mediates Drosophila early germ cell differentiation through targeting Bam.

Drosophila ovary has been one of the most mature and excellent systems for studying the in vivo regulatory mechanisms of stem cell fate determination. It has been well-known that the bone morphogenetic protein (BMP) signaling released by the niche cells promotes the maintenance of germline stem cells (GSCs) through inhibiting the transcription of the bag-of-marbles (bam) gene, which encodes a key factor for GSC differentiation. However, whether Bam is regulated at the post-translational level remains largely unknown. Here we show that the E3 ligase Cullin-2 (Cul2) is involved in modulating Bam ubiquitination, which occurs probably at multiple lysine residues of Bam's C-terminal region. Genetic evidence further supports the notion that Cul2-mediated Bam ubiquitination and turnover are essential for GSC maintenance and proper germline development. Collectively, our data not only uncovers a novel regulatory mechanism by which Bam is controlled at the post-translational level, but also provides new insights into how Cullin family protein determines the differentiation fate of early germ cells.

Explore the effects of Shidan granules on chronic atrophic gastritis using LC-MS based plasma metabolomics study.

Shidan granule (SDG), a traditional Chinese medicine in-hospital preparation, has been demonstrated to exert good effects on chronic atrophic gastritis (CAG) in clinics. However, the underlying mechanism of SDG against CAG is still unclear. This study utilized an untargeted plasma metabolomics approach to explore the potential mechanism of SDG in CAG rats using LC-MS and pattern recognition analysis. The results indicated that SDG could effectively improve the biochemical indexes and pathology features of CAG rats. Nineteen potential biomarkers (variable importance in projection > 1 and P < 0.05) contributing to CAG progress were identified. After SDG intervention, 17 biomarkers were obviously restored to normal levels. Further metabolic pathway analysis showed that aspartate and glutamate metabolism, arachidonic acid metabolism, arginine and proline metabolism, and TCA cycle were the most related pathways for SDG treatment. Based on these findings, the main mechanisms of SDG against CAG might be attributed to the regulatory effects of energy balance, inflammatory suppression, and improvement in disturbed amino acid and lipid metabolism. This study provided information for the mechanism research of SDG against CAG and would promote its clinical application.

Juglone triggers apoptosis of non-small cell lung cancer through the reactive oxygen species -mediated PI3K/Akt pathway.

Non-small cell lung cancer (NSCLC) is one of the most common malignancies worldwide, and oxidative stress plays a crucial role in its development. Juglone, a naturally occurring naphthoquinone in J. mandshurica, exhibits significant cytotoxic activity against various cancer cell lines. However, whether the anticancer activity of juglone is associated with oxidative stress remains unexplored. In this study, mouse Lewis lung cancer (LLC) and human non-small cell lung cancer A549 cells were used to explore the anticancer mechanisms of juglone. Juglone inhibited LLC and A549 cells viability, with IC50 values of 10.78 µM and 9.47 µM, respectively, for 24 h, and substantially suppressed the migration and invasion of these two lung cancer cells. Additionally, juglone arrested the cell cycle, induced apoptosis, increased the cleavage of caspase 3 and the protein expression of Bax and Cyt c, and decreased the protein expression of Bcl-2 and caspase-3. Furthermore, juglone treatment considerably increased intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels, but suppressed glutathione peroxidase 4 (GPX4) and superoxide dismutase (SOD) activities. It also inhibited the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway, which was attenuated by 1,3-diCQA (an activator of PI3K/Akt). Moreover, N-acetylcysteine (a ROS scavenger) partially reversed the positive effects of juglone in terms of migration, invasion, ROS production, apoptosis, and PI3K/Akt pathway-associated protein expression. Finally, in tumor-bearing nude mouse models, juglone inhibited tumor growth without any apparent toxicity and significantly induced apoptosis in NSCLC cells. Collectively, our findings suggest that juglone triggers apoptosis via the ROS-mediated PI3K/Akt pathway. Therefore, juglone may serve as a potential therapeutic agent for the treatment of NSCLC.

Combination of fenchone and sodium hyaluronate ameliorated constipation-predominant irritable bowel syndrome and underlying mechanisms.

We sought to explore the protective effect of the combination of fenchone (FE) and sodium hyaluronate (SH) on ice water-induced IBS-C rats and the potential mechanism. The neurotransmitter levels, including substance P (SP), motilin (MTL), 5-hydroxytryptamine (5-HT), and vasoactive intestinal peptide (VIP), were determined by ELISA methods. The stem cell factors (SCF)/c-Kit signaling pathway-related protein and mRNA levels were determined by western blot and reverse transcription quantitative polymerase chain reaction (RT-qPCR) analyses, respectively. The expressions of tight ZO-1, Occludin, and Claudin-1 were also measured by western blot assay and immunofluorescence staining. The 16S rRNA gene sequence was used to measure the composition of gut microbiota. The co-administration of FE and SH improved the body weight, number of fecal pellets, fecal moisture, abdominal with drawal reflex score, and gastrointestinal transit rate in IBS-C rats. The unique efficacy of combination depended on the regulation of balance between excitatory and inhibitory neurotransmitters, enhancement of intestinal barrier function, and activation of SCF/c-Kit pathway. The gut microbiota structure was also restored. The ability of FE combined with SH to regulate SCF/c-Kit signaling pathway, enhance intestinal barrier function, and modulate gut microbiota contributes to their efficacy in managing IBS-C in rats.

Astragalus mongholicus Bunge and Curcuma aromatica Salisb. modulate gut microbiome and bile acid metabolism to inhibit colon cancer progression.

Introduction: Alterations in the gut microbiome and bile acid metabolism are known to play a role in the development and progression of colon cancer. Medicinal plants like Astragalus mongholicus Bunge and Curcuma aromatica Salisb. (AC) have shown preferable therapeutic effect on cancer therapy, especially digestive tract tumors like colon cancer. However, the precise mechanisms of AC inhibiting colon cancer, particularly in relation to the gut microbiome and bile acid dynamics, are not fully understood. Methods: Our research aimed to investigate the anti-tumor properties of AC in mice with CT26 colon cancer and further investigate its underlying mechanism via intestinal microbiota. The size and pathological changes of solid tumors in colon cancer are used to evaluate the inhibitory effect of AC on colon cancer. Metagenomics and 16s rRNA gene sequencing were employed to clarify the dysbiosis in the gut microbiome of colon cancer and its impact on colon cancer. The levels of bile acids (BAs) in the feces of mice from each group were measured using UPLC-Qtrap-MS/MS. Results: AC effectively suppressed the growth of colon cancer and reduced histological damage. Notably, AC treatment led to changes in the gut microbiome composition, with a decrease in pathogenic species like Citrobacter and Candidatus_Arthromitus, and an increase in beneficial microbial populations including Adlercreutzia, Lachnospiraceae_UCG-001, and Parvibacter. Additionally, AC altered bile acid profiles, resulting in a significant decrease in pro-carcinogenic bile acids such as deoxycholic acid (DCA) and lithocholic acid (LCA), while increasing the concentration of the cancer-inhibitory bile acid, ursodeoxycholic acid (UDCA). Tracking and analyzing the data, AC may mainly upregulate FabG and baiA genes by increasing the relative abundance of Adlercreutzia and Parvibacter bacteria, which promoting the metabolism of pro-carcinogenic LCA. Discussion: These findings provide strong evidence supporting the role of AC in regulating gut microbiome-mediated bile acid metabolism, which is crucial in impeding the progression of colon cancer.

Dual-Mode Coupled Triboelectric Nanogenerator for Harvesting Random Vibration Energy.

As a new energy harvesting technology, triboelectric nanogenerators are widely used for vibration mechanical energy harvesting. However, the current schemes ignore the composite characteristics of vibration, with problems such as utilization and low collection efficiency. In this paper, a random resonance cantilever beam triboelectric nanogenerator (RCB-TENG) with dual-mode coupled is presented, the working mode is a coupling form of in-plane sliding and vertical contact-separation that can effectively collect complex vibration energy in transverse and longitudinal directions. The influences of the structural parameters of the RCB-TENG and different dielectric materials on the output performance are systematically investigated. The single vibration module achieved a power density of 463.56 mW/m2 and a transfer charge of 10.7 µC at a vibration frequency of 46 Hz, an increase in power density, and a transfer charge of 4.94 and 3.82 times, respectively, compared to the conventional contact-separation mode. Finally, the RCB-TENG was tested in practice, and it was observed that nine 1 W commercial LED bulbs and 500 5 mm diameter LED lamps were successfully lit. This work offers new ideas for distributed energy harvesting technologies and holds broad promise in the field of energy harvesting from wind, water, wave, and random vibrations caused by mechanical energy.

CG4968 positively regulates the immune deficiency pathway by targeting Imd protein in Drosophila.

Drosophila melanogaster relies solely on innate immunity to defend against various microbial pathogens. Although it is well-known that the adaptor protein Imd undergoes K63-linked ubiquitination to activate the downstream signaling cascades, its involvement with K48-linked ubiquitination and what is responsible for controlling this modification remain largely unknown. In this study, we explored the immunological function of CG4968, which encodes a typical ovarian tumour-associated protease (OTU)-type deubiquitinase (Dub) in flies. Our in vitro and vivo evidence demonstrated that CG4968 plays a positive role in governing the immune deficiency (IMD), but not the Toll innate immune response in an OTU domain-dependent manner. Mechanistically, we found that CG4968 is associated with Imd to restrict its K48-linked ubiquitination, thereby contributing to its turnover. Collectively, our study uncovered a novel regulatory mechanism involving the K48-linked ubiquitination of Imd in Drosophila innate immunity.

Ubiquitin C-Terminal Hydrolase L5 Plays an Essential Role in the Fly Innate Immune Defense against Bacterial Infection.

BACKGROUND: Drosophila ubiquitin carboxy-terminal hydrolase L5 (Uch-L5) functions as a critical component of the 26S proteasome to mediate degradation of polyubiquitinated proteins. It was recently shown to modulate tissue/organ development by targeting the Smoothened protein in the hedgehog pathway. However, whether it plays a role in controlling organismal immune response remains largely unknown. METHODS: Reverse transcription plus quantitative polymerase chain reaction (RT-qPCR), dual-luciferase, and Western blot assays were used to explore the potential function of Uch-L5 in the innate immune regulation in cultured Drosophila S2 cells. Further genetic manipulations and bacterial infections were conducted to confirm the findings in vivo. RESULTS: Silencing of Uch-L5 antagonizes the immune deficiency (IMD) but not the Toll innate immune signaling both in vitro and in vivo. Moreover, Uch-L5 positively contributes to the Drosophila innate immune response via its N-terminal Uch domain, which is the catalytical triad executing its deubiquitinase activity. CONCLUSIONS: Our studies shed light on a novel function of the deubiquitinase Uch-L5 in governing the anti-microbial defense in Drosophila.

A conserved role of bam in maintaining metabolic homeostasis via regulating intestinal microbiota in Drosophila.

Background: Previous studies have proven that bag-of-marbles (bam) plays a pivotal role in promoting early germ cell differentiation in Drosophila ovary. However, whether it functions in regulating the metabolic state of the host remains largely unknown. Methods: We utilized GC-MS, qPCR, and some classical kits to examine various metabolic profiles and gut microbial composition in bam loss-of-function mutants and age-paired controls. We performed genetic manipulations to explore the tissue/organ-specific role of bam in regulating energy metabolism in Drosophila. The DSS-induced mouse colitis was generated to identify the role of Gm114, the mammalian homolog of bam, in modulating intestinal homeostasis. Results: We show that loss of bam leads to an increased storage of energy in Drosophila. Silence of bam in intestines results in commensal microbial dysbiosis and metabolic dysfunction of the host. Moreover, recovery of bam expression in guts almost rescues the obese phenotype in bam loss-of-function mutants. Further examinations of mammalian Gm114 imply a similar biological function in regulating the intestinal homeostasis and energy storage with its Drosophila homolog bam. Conclusion: Our studies uncover a novel biological function of bam/Gm114 in regulating the host lipid homeostasis.

Effects of oral administration and intravenous injection of polygalacturonic acid on the immunomodulation and gut microbiota in UC mice.

This study aimed to compare the differences between oral administration and intravenous injection of polygalacturonic acid (PGA) in the regulation of immune and intestinal microflora in ulcerative colitis (UC) mice. PGA was administered orally or intravenously. PGA in the high-dose ig group was the most effective in treating UC by increasing colon length and downregulating disease activity index, histopathological score and proinflammatory cytokine levels. In spleen, the efficacy of PGA on restoring Th17/Treg balance in the high-dose iv group was better than that in the high-dose ig group, the opposite was observed in the lamina propria. The level of colonic IL-17A in the high-dose ig group was lower than that in the high-dose iv group, the opposite was observed for that of colonic IL-10. Western blot and immunohistochemistry analysis revealed that PGA in the high-dose ig group decreased the protein expression of RORγt, and increased that of FOXP3. Furthermore, PGA in the high-dose ig group was more effective than that in the high-dose iv group in improving the intestinal microflora structure. Our results suggest that in immune regulation, oral PGA is more effective in the lamina propria and gut microbiota while intravenous PGA is more effective in the spleen.

Exploring the mechanism of action of Sanzi formula in intervening colorectal adenoma by targeting intestinal flora and intestinal metabolism.

Background: Sanzi formula (SZF) is a kind of Chinese herbal compound that has a certain effect on the prevention and treatment of colorectal adenoma (CRA), which can prevent and control the process of CRA-cancer transformation. In this study, we explored the mechanism of action of SZF in anti-CRA using 16S rRNA sequencing and metabolomics technology. Methods: Mice were randomly divided into three groups: Control group, Apcmin/+ model group, and SZF treatment group. Except for the Control group, which used C57BL/6 J mice, the remaining two groups used Apcmin/+ mice. The Control group and Apcmin/+ model group were treated with ultrapure water by gavage, while the SZF treatment group was treated with SZF for 12 weeks. During this period, the physical changes of mice in each group were observed. The gut microbiota was determined by high-throughput sequencing of the 16S rRNA gene, and LC-ESI-MS/MS was used for colorectal metabolomics analysis. Results: Sequencing of the 16S rRNA gut flora yielded 10,256 operational taxonomic units and metabolomic analysis obtained a total of 366 differential metabolites. The intestinal flora analysis showed that SZF could improve intestinal flora disorders in Apcmin/+ mice. For instance, beneficial bacteria such as Gastranaerophilales significantly increased and harmful bacteria such as Angelakisella, Dubosiella, Muribaculum, and Erysipelotrichaceae UCG-003 substantially decreased after the SZF intervention. In addition, metabolomic data analysis demonstrated that SZF also improved the colorectal metabolic profile of Apcmin/+ mice. In Apcmin/+ mice, metabolites such as Anserine and Ectoine were typically increased after SZF intervention; in contrast, metabolites such as Taurocholic acid, Taurochenodesoxycholic acid, Hyocholic acid, Cholic acid, and Tauro-alpha-muricholic acid showed noteworthy reductions. Metabolic flora association analysis indicated that 13 differential flora and 11 differential metabolites were associated. Conclusion: SZF affects the abundance of specific intestinal flora and regulates intestinal flora disorders, improves colorectal-specific metabolites, and ameliorates intestinal metabolic disorders to prevent and treat CRA. Furthermore, the application of intestinal flora and colorectal metabolomics association analysis offers new strategies to reveal the mechanism of action of herbal medicines for the treatment of intestinal diseases.

A Toll-dependent Bre1/Rad6-cact feedback loop in controlling host innate immune response.

The Toll signaling pathway was initially identified for its involvement in the control of early embryogenesis. It was later shown to be also part of a major innate immune pathway controlling the expression of anti-microbial peptides in many eukaryotes including humans; cactus, the essential negative regulator of this pathway in flies, was found to be induced in parallel to the Toll-dependent activation process during immune defenses. We were interested in the mechanisms of this dual effect and provide here evidence that upon pathogenic stimuli, dorsal, one of the transcription factors of the fly Toll pathway, can induce the expression of the E3 ligase Bre1. We further show that Bre1 complexes with the E2 Rad6 to mono-ubiquitinate histone H2B and to promote the transcription of cactus to achieve homeostasis of the Toll immune response. Our studies characterize a Toll signal-dependent regulatory machinery in governing the Toll pathway in Drosophila.

A Feedback Regulatory Loop Involving dTrbd/dTak1 in Controlling IMD Signaling in Drosophila Melanogaster.

Negative regulators of the inflammatory responses are essential for the maintenance of immune homeostasis and organismal fitness. In Drosophila, the deubiquitinase (Dub) dTrbd selectively restricts the K63-linked ubiquitination modification of dTak1, a pivotal kinase of the IMD signaling pathway, to regulate the IMD innate immune response. However, which domain and how it functions to enable dTrbd's activity remain unexplored. Here, we provide compelling evidence showing that the NZF domain of dTrbd is essential for its association with dTak1. Meanwhile, the Linker region of dTrbd is involved in modulating its condensation, a functional state representing the Dub enzymatical activity of dTrbd. Of interest, the activated IMD signals following bacterial stimuli enhance the dTrbd/dTak1 interaction, as well as the condensate assembly and Dub enzymatical activity of dTrbd. Collectively, our studies shed light on the dual mechanisms by which the IMD signaling-mediated feedback loop of dTrbd/dTak1 precisely regulates the innate immune response in Drosophila.

Corrigendum: A feedback regulatory loop involving dTrbd/dTak1 in controlling IMD signaling in Drosophila Melanogaster.

[This corrects the article DOI: 10.3389/fimmu.2022.932268.].

Aspirin Positively Contributes to Drosophila Intestinal Homeostasis and Delays Aging through Targeting Imd.

The intestine, a high-turnover tissue, plays a critical role in regulating aging and health in both vertebrates and invertebrates. Maintaining the epithelial barrier function of the intestine by preserving innate immune homeostasis significantly delays aging and prevents mortality. In an effort to explore effective chemicals and materials that can improve intestinal integrity, we performed a nonbiased screen utilizing Drosophila as an animal model. We showed that long-term uptake of aspirin markedly prevented age-onset gut leakage, the over-proliferation of intestinal stem cells, and the dysbiosis of commensal microbiota in fruit flies. Mechanistically, aspirin efficiently downregulated chronic activation of intestinal immune deficiency signaling during aging. Furthermore, our in vivo and in vitro biochemical analyses indicated that aspirin is a negative modulator in control of the K63-linked ubiquitination of Imd. Our findings uncover a novel regulatory mechanism by which aspirin positively modulates intestinal homeostasis, thus delaying aging, in Drosophila.

Juglone regulates gut microbiota and Th17/Treg balance in DSS-induced ulcerative colitis.

Juglone, mainly isolates from the green walnut husks of Juglans mandshurica, exhibits anti-cancer and anti-inflammaroty activities. But its protection on ulcerative colitis (UC) has never been explored. In this study, we first evaluated whether juglone ameliorated UC, and investigated its effects on gut microbiota and Th17/Treg balance in DSS-induced UC mice model. The model was established by administrating 2.7% DSS for seven days. Juglone was given daily by gavage for ten days, once a day. The disease activity index (DAI) decrease and pathological characteristics improvement demonstrated that the UC in mice was alleviated by juglone. Juglone treatment significantly inhibited the protein levels of IL-6, TNF-α and IL-1ß, improved the protein expression of IL-10. In addition, juglone altered microbial diversity and gut microbiota composition, including the enhancement of the ratio of Firmicutes to Bacteroidota and the abundance of Actinobacteriota, and decrease of the abundance of Verrucomicrobiota. Juglone treatment also inhibited the protein expressions of IL-6, STAT3 and RORγt, meanwhile improved the protein level of FOXP3. Furthermore, juglone inhibited Th17 development and increased Treg generation, beneficial to Th17/Treg balance. Together, we herein provided the first evidence to support that juglone, especially the high dose, possibly protected mice against UC by modulating gut microbiota and restoring Th17/Treg homeostasis.