MiR827 positively regulates the resistance to chilli veinal mottle virus by affecting the expression of FBPase in Nicotiana benthamiana.

MicroRNA(miRNA) is a class of non-coding small RNA that plays an important role in plant growth, development, and response to environmental stresses. Unlike most miRNAs, which usually target homologous genes across a variety of species, miR827 targets different types of genes in different species. Research on miR827 mainly focuses on its role in regulating phosphate (Pi) homeostasis of plants, however, little is known about its function in plant response to virus infection. In the present study, miR827 was significantly upregulated in the recovery tissue of virus-infected Nicotiana tabacum. Overexpression of miR827 could improve plants resistance to the infection of chilli veinal mottle virus (ChiVMV) in Nicotiana benthamiana, whereas interference of miR827 increased the susceptibility of the virus-infected plants. Further experiments indicated that the antiviral defence regulated by miR827 was associated with the reactive oxygen species and salicylic acid signalling pathways. Then, fructose-1,6-bisphosphatase (FBPase) was identified to be a target of miR827, and virus infection could affect the expression of FBPase. Finally, transient expression of FBPase increased the susceptibility to ChiVMV-GFP infection in N. benthamiana. By contrast, silencing of FBPase increased plant resistance. Taken together, our results demonstrate that miR827 plays a positive role in tobacco response to virus infection, thus providing new insights into understanding the role of miR827 in plant-virus interaction.

Reclaiming Power or Reinforcing Inequities: Exploring Egg Freezing Debates on Social Media.

In China, unmarried women are prohibited from egg freezing despite high demand and declining fertility rates. Within such a context, this article aims to examine public attitudes toward reproduction and egg-freezing on social media, with particular attention paid to how these discussions reflect the multi-level determinants influencing decision-making regarding egg-freezing practices. Within the context of Chinese gender ideology, we conducted a critical discourse analysis of 1,437 Weibo posts discussing egg-freezing. Our analysis identified four significant themes: reconstructing romantic relationships and family structures, conspiracy theories and distrust surrounding assisted reproduction, exposing and challenging reproductive policies within a patriarchal framework, and interconnections and stratification among women. Accentuated by the egg-freezing discourse, we argue that current Chinese women's bodily autonomy is entangled with traditional norms and state control, underscoring the intricate interplay between individual choice and societal dynamics, as well as the ideological contradictions at the intersection of Western technological influence and Chinese societal structures. Furthermore, we illuminate the challenging landscape faced by online feminist movements within such a complex context. Our findings set the stage for shaping future initiatives focused on advancing reproductive justice and empowering fertility choices among Chinese women.

Integrating Network Pharmacology and In Vitro Experiments for Assessing the Anti-Tumor Effects of Phyllanthus Urinaria L Anti-neoplastic Decoction in Hepatocellular Carcinoma.

Background: In China, traditional Chinese medicine (TCM) is an important part of the comprehensive treatment of hepatocellular carcinoma (HCC), and Chinese herb formulas with the effect of "yiqi jianpi jiedu huayu" (replenishing qi, strengthening spleen, and removing toxicity and blood stasis) are the common and efficient treatments for HCC. However, the mechanism of these formulas in treating HCC remain unclear. Objective: In this paper, our goal is to explore the potential mechanism of Phyllanthus urinaria L anti-neoplastic decoction (PAD), the representative formula of "yiqi jianpi jiedu huayu", in treating HCC. Design: The research team performed the network pharmacology and in vitro experiment (preparation of PAD aqueous extract, cell cultures and MTT assay, cell apoptosis assay, wound healing assay, transwell assays, western blot). Setting: The study took place in the Department of Hepatology, the Fourth Clinical Medical College of Guangzhou University of Chinese Medicine (Shenzhen Traditional Chinese Medicine Hospital), China. Outcome Measures: The active components and targets of PAD and HCC targets were screened by five Chinese herbs and two disease databases respectively. The network pharmacology was utilized to construct the relationship network between PAD and HCC, and the mechanism was predicted by pathway enrichment analysis. The experiment was performed to verify the intervention effect of PAD on HCC and phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway. Results: The relationship network between PAD and HCC suggested that PAD mainly regulated the potential therapeutic targets of HCC by key active components such as quercetin, luteolin, calycosin, wogonin, and pinocembrin. Pathway analysis demonstrated PAD could play an anti-HCC effect via multiple pathways (e.g., PI3K/Akt). Results of the experiment showed that PAD could effectively inhibit the proliferation and migration of HCC cells, and promote HCC cells apoptosis in a concentration-dependent behavior. Additionally, PAD could decrease the protein expression of phosphorylated PI3K/Akt. Conclusion: PAD mainly exerts an anti-HCC effect through multiple active components represented by quercetin and multiple pathways represented by the PI3K/Akt pathway. This study provided an experimental basis for the clinical application of PAD.

Risk factors of delirium in a paediatric intensive care unit: A prospective case series study.

BACKGROUND: Delirium is one of the most common complications in critically ill children. Once delirium occurs, it will cause physical and psychological distress in children and increase the length of their ICU stay and hospitalization costs. Understanding the risk factors for delirium in critically ill children can help develop targeted nursing interventions to reduce the incidence of delirium. AIMS: To investigate the incidence and the risk factors of delirium in the paediatric intensive care unit (PICU). STUDY DESIGN: We performed a prospective observational study in critically ill patients in the PICU between February and July 2020. Delirium was diagnosed by the Cornell Assessment of Paediatric Delirium (CAPD) and the Richmond Agitation Sedation Scale and analysed via univariate analysis and multivariate logistic regression to determine the independent risk factors of delirium in critically ill children. RESULTS: The study enrolled 315 patients ranging in age from 1-202 (65.3-54.3) months, with 56.2% (n = 177) being male. The incidence of delirium was 29.2% (n = 92) according to CAPD criteria. Among them, 33 cases (35.9%) were of hyperactive delirium, 16 cases (17.4%) were of hypoactive delirium, and 43 cases (46.7%) were of mixed delirium. By using stepwise logistic regression, the independent risk factors of delirium included mechanical ventilation (odds ratio [OR], 11.470; 95% confidence interval [CI], 4.283-30.721), nervous system disease (OR, 5.596; 95%CI, 2.445 to 12.809), developmental delay (OR, 5.157; 95% CI, 1.990-13.363), benzodiazepine (OR, 3.359; 95% CI 1.278-8.832), number of catheters (OR, 1.918; 95% CI, 1.425 to 2.582), and age (OR, 0.985; 95% confidence interval CI, 0.976-0.993). CONCLUSIONS: Delirium is a common complication in the PICU. The independent risk factors include mechanical ventilation, nervous system disease, developmental delay, benzodiazepines, higher number of catheters, and younger age. This study may help develop intervention strategies to reduce the incidence of delirium in critically ill children by targeting modifiable risk factors. RELEVANCE TO CLINICAL PRACTICE: Recommendations for practice include paying attention to high-risk children in the ICU who are prone to delirium, removing influencing factors as soon as possible, and providing targeted nursing interventions.

Effects of Washed Microbiota Transplantation on Serum Uric Acid Levels, Symptoms, and Intestinal Barrier Function in Patients with Acute and Recurrent Gout: A Pilot Study.

INTRODUCTION: Gut dysbiosis has been reported to be closely associated with gout. Washed microbiota transplantation (WMT) is considered as an effective way to restore a healthy gut microbiota with less adverse events than the conventional fecal microbiota transplantation. In this study, we aimed to evaluate the effects of WMT on serum uric acid levels, symptoms, and the intestinal barrier function in patients with acute and recurrent gout. METHODS: We performed a pilot study of WMT for acute and recurrent gout. The primary outcome was the changes in the serum uric acid level and gout symptoms. The secondary outcomes included the changes in levels of diamine oxidase (DAO), D-lactic acid, and endotoxin. RESULTS: Eleven patients received WMT treatment. The averaged serum uric acid levels in patients with gout reduced after WMT (p = 0.031), accompanied with a decrease in the frequency and duration time of acute gout flares (p < 0.01). The levels of DAO, D-lactic acid, and endotoxin were higher in patients than in healthy donors (p < 0.05). After WMT treatment, the levels of DAO and endotoxin decreased (p < 0.05). CONCLUSIONS: WMT is effective for reducing serum uric acid levels and improving gout symptoms in patients with gout and contributes to improve their impaired intestinal barrier function.

The NLRP3 inflammasome: Multiple activation pathways and its role in primary cells during ventricular remodeling.

Inflammasomes are a group of multiprotein signaling complexes located in the cytoplasm. Several inflammasomes have been identified, including NLRP1, NLRP2, NLRP3, AIM2, and NLRC4. Among them, NLRP3 was investigated in most detail, and it was reported that it can be activated by many different stimuli. Increased NLRP3 protein expression and inflammasome assembly lead to caspase-1 mediated maturation and release of IL-1ß, which triggers inflammation and pyroptosis. The activation of the NLRP3 inflammasome has been widely reported in studies of tumors and neurological diseases, but relatively few studies on the cardiovascular system. Ventricular remodeling (VR) is an important factor contributing to heart failure (HF) after myocardial infarction (MI). Consequently, delaying VR is of great significance for improving heart function. Studies have shown that the NLRP3 inflammasome plays an essential role in the process of VR. Here, we reviewed the latest studies on the activation pathway of the NLRP3 inflammasome, focusing on the effects of the NLRP3 inflammasome in primary cells during VR, and finally discuss future research directions in this field.

A chloride channel in rat pancreatic acinar AR42J cells is sensitive to extracellular acidification and dependent on ROS.

Extracellular acidification, playing a promoting role in the process of acute pancreatitis, has been reported to activate Cl- channels in several types of cells. However, whether extracellular acidification aggravates acute pancreatitis via activating Cl- channels remains unclear. Here, we investigated the effects of extracellular acidification on Cl- channels in rat pancreatic acinar AR42J cells using whole-cell patch-clamp recordings. We found that extracellular acidification induced a moderately outward-rectified Cl- current, with a selectivity sequence of I- > Br- ≥ Cl- > gluconate-, while intracellular acidification failed to induce the currents. The acid-sensitive currents were inhibited by Cl- channel blockers, 4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate and 5-Nitro-2-(3-phenylpropylamino) benzoic acid. After ClC-3 was silenced by ClC-3 shRNA, the acid-sensitive Cl- currents were attenuated significantly, indicating that ClC-3 plays a vital role in the induction of acid-sensitive Cl- currents. Extracellular acid elevated the intracellular level of reactive oxygen species (ROS) significantly, prior to inducing Cl- currents. When ROS production was scavenged, the acid-sensitive Cl- currents were abolished. Whereas, the level of acid-induced ROS was unaffected with silence of ClC-3. Our findings above demonstrate that extracellular acidification induces a Cl- current in pancreatic acinar cells via promoting ROS generation, implying an underlying mechanism that extracellular acidification might aggravate acute pancreatitis through Cl- channels.

Starvation-induced autophagy is up-regulated via ROS-mediated ClC-3 chloride channel activation in the nasopharyngeal carcinoma cell line CNE-2Z.

Nutrient deficiency develops frequently in nasopharyngeal carcinoma cell (CNE-2Z) due to the characteristics of aggregation and uncontrolled proliferation. Therefore, starvation can induce autophagy in these cells. Chloride channel 3 (ClC-3), a member of the chloride channel family, is involved in various biological processes. However, whether ClC-3 plays an important role in starvation-induced autophagy is unclear. In this study, Earle's balanced salt solution (EBSS) was used to induce autophagy in CNE-2Z cells. We found that autophagy and the chloride current induced by EBSS were inhibited by chloride channel blockers. ClC-3 knockdown inhibited the degradation of LC3-II and P62. Furthermore, when reactive oxygen species (ROS) generation was suppressed by antioxidant N-acetyl-l-cysteine (L-NAC) pretreatment, EBSS-induced autophagy was inhibited, and the chloride current was unable to be activated. Nevertheless, ClC-3 knockdown had little effect on ROS levels, indicating that ROS acted upstream of ClC-3 and that both ROS and ClC-3 participated in EBSS-induced autophagy regulation in CNE-2Z.

The apoptotic effect of Zoledronic acid on the nasopharyngeal carcinoma cells via ROS mediated chloride channel activation.

Zoledronic acid (ZA), a third-generation bisphosphonate, has been applied for treatment of bone metastases caused by malignant tumors. Recent studies have found its anti-cancer effects on various tumor cells. One of the mechanisms of anti-cancer effects of ZA is induction of apoptosis. However, the mechanisms of ZA-induced apoptosis in tumor cells have not been clarified clearly. In this study, we investigated the roles of chloride channels in ZA-induced apoptosis in nasopharyngeal carcinoma CNE-2Z cells. Apoptosis and chloride current were induced by ZA and suppressed by chloride channel blockers. After the knockdown of ClC-3 expression by ClC-3 siRNA, ZA-induced chloride current and apoptosis were significantly suppressed, indicating that the chloride channel participated in ZA-induced apoptosis may be ClC-3. When reactive oxygen species (ROS) generation was inhibited by the antioxidant N-acetyl-L-cysteine (L-NAC), ZA-induced apoptosis and chloride current were blocked accordingly, suggesting that ZA induces apoptosis through promoting ROS production and subsequently activating chloride channel.

Estradiol activates chloride channels via estrogen receptor-α in the cell membranes of osteoblasts.

Estrogen plays important roles in regulation of bone formation. Cl- channels in the ClC family are expressed in osteoblasts and are associated with bone physiology and pathology, but the relationship between Cl- channels and estrogen is not clear. In this study the action of estrogen on Cl- channels was investigated in the MC3T3-E1 osteoblast cell line. Our results show that 17ß-estradiol could activate a current that reversed at a potential close to the Cl- equilibrium potential, with a sequence of anion selectivity of I- > Br- > Cl- > gluconate, and was inhibited by the Cl- channel blockers 5-nitro-2-(3-phenylpropylamino)-benzoate and 4,4'-diisothiocyano-2,2'-stilbene disulfonic acid. Knockdown of ClC-3 Cl- channel expression by a specific small interfering RNA to ClC-3 attenuated activation of the 17ß-estradiol-induced Cl- current. Extracellular application of membrane-impermeable 17ß-estradiol-albumin conjugates activated a similar current. The estrogen-activated Cl- current could be inhibited by the estrogen receptor (ER) antagonist fulvestrant (ICI 182780). The selective ERα agonist, but not ERß agonist, activated a Cl- current similar to that induced by 17ß-estradiol. Silencing ERα expression prevented activation of estrogen-induced currents. Immunofluorescence and coimmunoprecipitation experiments demonstrated that ClC-3 Cl- channels and ERα were colocalized and closely related in cells. Estrogen promoted translocation of ClC-3 and ERα to the cell membrane from the nucleus. In conclusion, our findings show that Cl- channels can be activated by estrogen via ERα on the cell membrane and suggest that the ClC-3 Cl- channel may be one of the targets of estrogen in the regulation of osteoblast activity.

Cisplatin activates volume-sensitive like chloride channels via purinergic receptor pathways in nasopharyngeal carcinoma cells.

Cisplatin-based concomitant chemoradiotherapy is considered as the standard treatment for locally advanced nasopharyngeal carcinoma patients. However, the curative efficacy of cisplatin-based chemotherapy is limited because of the occurrence of cisplatin resistance. Some researches indicate that activating the volume-sensitive Cl(-) channel might be a new strategy for the reduction of cisplatin resistance. However, little is known about the activation pathway of the Cl(-) channels activated by cisplatin. In this study, the cisplatin-activated chloride current was investigated using the whole cell patch-clamp technique in the poorly differentiated nasopharyngeal carcinoma cells (CNE-2Z cells), and the activation pathway of the current was also discussed. The results showed that extracellular application of cisplatin activated a Cl(-) current, showing the properties of significant outward rectification, intracellular ATP dependency, and a selectivity sequence of I(-) > Br(-) > Cl(-) > gluconate, and being inhibited by the Cl(-) channel inhibitors tamoxifen and extracellular ATP. These characteristics are similar to those of the volume-sensitive Cl(-) current in CNE-2Z cells, indicating that cisplatin induces the Cl(-) current by activating the volume-sensitive like chloride channel. The cisplatin-activated current was blocked by suramin (a wide-spectrum purinergic antagonist) and RB2 (a relatively selective P2Y antagonist). In addition, the current was depressed by extracellular application of apyrase. The apoptotic volume decrease induced by cisplatin was also attenuated by RB2. P2Y receptors were expressed in CNE-2Z cells. These results suggest that cisplatin can induce a Cl(-) current by activating volume-sensitive like Cl(-) channels through the P2Y purinoceptor pathway.

Sunlight-driven reduction of silver ion to silver nanoparticle by organic matter mitigates the acute toxicity of silver to Daphnia magna.

Due to the unique antibacterial activities, silver nanoparticles (AgNPs) have been extensively used in commercial products. Anthropogenic activities have released considerable AgNPs as well as highly toxic silver ion (Ag(+)) into the aquatic environment. Our recent study revealed that ubiquitous natural organic matter (NOM) could reduce Ag(+) to AgNP under natural sunlight. However, the toxic effect of this process is not well understood. In this work, we prepared mixture solution of Ag(+) and AgNPs with varied Ag(+)% through the sunlight-driven reduction of Ag(+) by NOM and investigated the acute toxicity of the solutions on Daphnia magna. Formation of AgNPs was demonstrated and characterized by comprehensive techniques and the fraction of unconverted Ag(+) was determined by ultrafiltration-inductively coupled plasma mass spectrometry determination. The formation of AgNPs enhanced significantly with the increasing of solution pH and cumulative photosynthetically active radiation of sunlight. The toxicity of the resulting solution was further investigated by using freshwater crustacean D. magna as a model and an 8hr-median lethal concentration (LC50) demonstrated that the reduction of Ag(+) by NOM to AgNPs significantly mitigated the acute toxicity of silver. These results highlight the importance of sunlight and NOM in the fate, transformation and toxicity of Ag(+) and AgNPs, and further indicate that the acute toxicity of AgNPs should be mainly ascribed to the dissolved Ag(+) from AgNPs.

Water chemistry controlled aggregation and photo-transformation of silver nanoparticles in environmental waters.

The inevitable release of engineered silver nanoparticles (AgNPs) into aquatic environments has drawn great concerns about its environmental toxicity and safety. Although aggregation and transformation play crucial roles in the transport and toxicity of AgNPs, how the water chemistry of environmental waters influences the aggregation and transformation of engineered AgNPs is still not well understood. In this study, the aggregation of polyvinylpyrrolidone (PVP) coated AgNPs was investigated in eight typical environmental water samples (with different ionic strengths, hardness, and dissolved organic matter (DOM) concentrations) by using UV-visible spectroscopy and dynamic light scattering. Raman spectroscopy was applied to probe the interaction of DOM with the surface of AgNPs. Further, the photo-transformation and morphology changes of AgNPs in environmental waters were studied by UV-visible spectroscopy, inductively coupled plasma mass spectrometry, and transmission electron microscopy. The results suggested that both electrolytes (especially Ca(2+) and Mg(2+)) and DOM in the surface waters are key parameters for AgNP aggregation, and sunlight could accelerate the morphology change, aggregation, and further sedimentation of AgNPs. This water chemistry controlled aggregation and photo-transformation should have significant environmental impacts on the transport and toxicity of AgNPs in the aquatic environments.

Human umbilical cord mesenchymal stem cells promote carcinoma growth and lymph node metastasis when co-injected with esophageal carcinoma cells in nude mice.

BACKGROUND: Human umbilical cord blood derived-mesenchymal stem cells (hUCMSCs) offer an attractive alternative to bone marrow-derived MSCs (BMMSCs) for cell-based therapy as it is a less invasive source of biological material. However, limited studies have been conducted with hUCMSCs as compared to BMMSCs. The present study was conducted to evaluate the effects of hUCMSCs in esophageal carcinoma (EC). METHODS: hUCMSCs together with EC cells were transplanted subcutaneously into BALB/c nude mice to observe the effects of hUCMSCs on tumor establishment. hUCMSCs injected through the caudal vein to the mice with pre-established EC to observe the effects of hUCMSCs on tumor outgrowth. In order to elucidate the underlying mechanisms, we also performed in vitro experiments including directly co-culture, transwell assay, proliferation assay and western blotting analysis. RESULTS: hUCMSCs promoted EC formation in nude mice. In the in vivo model of pre-established EC, intravenously injected hUCMSCs potently promoted tumor growth. When in vitro co-cultured with hUCMSCs, EC cells proliferation increased. After co-cultured with hUCMSCs through transwell system, EC cells showed increased proliferation. Through transwell assay, we also observed that EC cells recruited MSCs, and MSCs promoted EC cells migration and invasion. Western blotting data showed that the expressions of proliferation related proteins Bcl-2, survivin and metastasis related proteins MMP-2 and MMP-9 were up-regulated in the EC cells transwell co-cultured with hUCMSCs. CONCLUSIONS: Our results indicated that hUCMSCs could favor tumor growth in vivo and in vitro. Thus, the exploitation of hUCMSCs in new therapeutic strategies should be cautious under the malignant conditions.

Effect of lidocaine pumped through hepatic artery to relieve pain of hepatic artery infusion chemotherapy.

Background: This study aims to explore the analgesic effect of lidocaine administered through the hepatic artery during hepatic artery infusion chemotherapy (HAIC) for hepatocellular carcinoma (HCC). Methods: A total of 45 HCC patients were randomly divided into a study group and a control group. Both groups received oxaliplatin (OXA) based FOLFOX protocol via electronic infusion pump. The study group was continuously infused with 100 mg of lidocaine during HAIC, while 5% glucose solution was infused in the same way as described above. Changes in vital signs, visual analogue score (VAS) and general comfort score (GCQ scale) were recorded before surgery (Time point 0), at the end of infusion (Time point 01), 1 h after HAIC (Time point 02), 3 h after HAIC (Time point 03) and 6 h after HAIC (Time point 04). Results: At each point of time from Time point 0 through Time point 04, the differences in MAP, RR and SPO2 between the two groups were not statistically significant (P > 0.05). At each point of time from Time point 01 through Time point 04, the mean VAS scores in the study group were smaller and GCQ scores were higher than those in the control group, and the differences were both statistically significant (P < 0.05). Conclusions: Lidocaine infusion through the hepatic artery during HAIC effectively reduces intraoperative and postoperative pain and improves patient satisfaction with pain management, making it a valuable technique for clinical practice.

Nursing Care of a Child With Delirium Receiving Venoarterial Extracorporeal Membrane Oxygenation: A Case Report.

INTRODUCTION: Children receiving extracorporeal membrane oxygenation are prone to delirium. This case report describes the nursing care of a child with delirium who received venoarterial extracorporeal membrane oxygenation. Relevant interventions and precautions are also discussed. CLINICAL FINDINGS: A 6-year-old girl was admitted to the pediatric intensive care unit with a 2-day history of vomiting and fever. The child underwent cannulation for venoarterial extracorporeal membrane oxygenation. DIAGNOSIS: The child was diagnosed with acute fulminant myocarditis, cardiac shock, and ventricular arrhythmia. INTERVENTIONS: On the third day of extracorporeal membrane oxygenation, bedside nurses began using the Cornell Assessment of Pediatric Delirium to assess the child for delirium symptoms. The team of physicians and nurses incorporated a nonpharmacologic delirium management bundle into pediatric daily care. Delirium screening, analgesia and sedation management, sleep promotion, and family participation were implemented. OUTCOMES: During the 18 days of pediatric intensive care unit hospitalization, the child had 6 days of delirium: 1.5 days of hypoactive delirium, 1.5 days of hyperactive delirium, and 3 days of mixed delirium. The child was successfully discharged home on hospital day 22. CONCLUSION: Caring for a child with delirium receiving venoarterial extracorporeal membrane oxygenation required multidimensional nursing capabilities to prevent and reduce delirium while ensuring safe extracorporeal membrane oxygenation. This report may assist critical care nurses caring for children under similar circumstances.

Enteral nutrition promotes the remission of colitis by gut bacteria-mediated histidine biosynthesis.

BACKGROUND: Exclusive enteral nutrition (EEN) is an important alternative strategy for patients with Crohn's disease (CD), and during this process, microbiota alterations have been observed. However, the underlying mechanisms by which EEN reduces intestinal inflammation are currently unclear. METHODS: The therapeutic potential of enteral nutrition (EN) was assessed using various mouse models. Fecal full-length 16S rDNA sequencing analysis and several CD metagenome datasets were used to identify the candidate therapeutic bacteria Faecalibaculum rodentium (F. rodentium). Whole genome sequencing of F. rodentium and widely-targeted metabolome analysis of the supernatant showed that EN-induced F. rodentium accumulation protected against colitis via histidine biosynthesis. FINDINGS: The therapeutic potential of EN therapy was observed in both dextran sulfate sodium (DSS)-induced colitis and Il10-/- spontaneous colitis mouse models. Accumulation of F. rodentium after EN therapy was determined using full-length 16S rDNA sequencing and verified with several metagenome datasets from patients with CD. Colonization of an isolated F. rodentium could reduce colitis in Il10-/- mice. Significant histidine enrichment was observed in the F. rodentium culture supernatant, and a series of histidine biosynthesis genes were observed in the F. rodentium genome. Engineered Escherichia coli Nissle 1917 (EcN), encoding the heterologous hisG of F. rodentium (EcN-hisG), which was a key driver of histidine biosynthesis in F. rodentium, was found to protect against colitis. INTERPRETATION: This study suggests that EN-induced F. rodentium accumulation protects against colitis in mice via gut bacteria-mediated histidine biosynthesis. FUNDING: A full list of funding bodies can be found in the Acknowledgements section.

Dynamic and balanced regulation of the thrABC operon gene for efficient synthesis of L-threonine.

L-threonine is an essential amino acid used widely in food, cosmetics, animal feed and medicine. The thrABC operon plays an important role in regulating the biosynthesis of L-theronine. In this work, we systematically analyzed the effects of separating thrAB and thrC in different proportions on strain growth and L-threonine production in Escherichia coli firstly. The results showed that higher expression of thrC than thrAB enhanced cell growth and L-threonine production; however, L-threonine production decreased when the thrC proportion was too high. The highest L-threonine production was achieved when the expression intensity ratio of thrAB to thrC was 3:5. Secondly, a stationary phase promoter was also used to dynamically regulate the expression of engineered thrABC. This strategy improved cell growth and shortened the fermentation period from 36 h to 24 h. Finally, the acetate metabolic overflow was reduced by deleting the ptsG gene, leading to a further increase in L-threonine production. With these efforts, the final strain P 2.1 -2901ΔptsG reached 40.06 g/L at 60 h fermentation, which was 96.85% higher than the initial control strain TH and the highest reported titer in shake flasks. The maximum L-threonine yield and productivity was obtained in reported fed-batch fermentation, and L-threonine production is close to the highest titer (127.30 g/L). In this work, the expression ratio of genes in the thrABC operon in E. coli was studied systematically, which provided a new approach to improve L-threonine production and its downstream products.

A synthetic population-level oscillator in non-microfluidic environments.

Synthetic oscillators have become a research hotspot because of their complexity and importance. The construction and stable operation of oscillators in large-scale environments are important and challenging. Here, we introduce a synthetic population-level oscillator in Escherichia coli that operates stably during continuous culture in non-microfluidic environments without the addition of inducers or frequent dilution. Specifically, quorum-sensing components and protease regulating elements are employed, which form delayed negative feedback to trigger oscillation and accomplish the reset of signals through transcriptional and post-translational regulation. We test the circuit in devices with 1 mL, 50 mL, 400 mL of medium, and demonstrate that the circuit could maintain stable population-level oscillations. Finally, we explore potential applications of the circuit in regulating cellular morphology and metabolism. Our work contributes to the design and testing of synthetic biological clocks that function in large populations.

Reduced type 3 innate lymphoid cells related to worsening kidney function in renal dysfunction.

Intestinal mucosa barrier injury and immunity imbalance contribute to chronic kidney disease (CKD) progression. Type 3 innate lymphoid cells (ILC3s) are essential for normal intestinal homeostasis. Nevertheless, the relationship between ILC3s and CKD remains largely unknown. The aim of this study was to investigate the relationship linking ILC3s to clinical indicators among patients with renal dysfunction. The levels of circulating ILC3s and dendritic cells, as well as their subsets, in patients with renal dysfunction and healthy controls were determined through flow cytometry. The levels of human plasma granulocyte-macrophage colony-stimulating factor (GM-CSF) were measured using enzyme-linked immunosorbent assay. Renal function was evaluated by measuring the estimated glomerular filtration rate (eGFR), as well as the levels of serum creatinine, blood urea nitrogen (BUN), and uric acid. The results revealed that the proportion of peripheral ILC3s was significantly decreased in patients with renal dysfunction. This reduction was positively associated with the levels of eGFR, and inversely associated with the levels of BUN and uric acid. Similarly, the percentage of circulating C-C motif chemokine receptor 6-positive (CCR6 +) ILC3s was also obviously reduced, and demonstrated positive and negative associations with the levels of eGFR and BUN, respectively. Furthermore, the levels of CCR6 + ILC3s correlated positively with those of GM-CSF, as well as type 1 conventional dendritic cells (cDC1s), which also decreased in parallel with kidney function. Thus, the reduction of ILC3s, particularly CCR6 + ILC3s, was related to worsening kidney function in patients with renal dysfunction. This effect may delay renal function impairment by regulating cDC1s via the secretion of GM-CSF, indicating that CCR6 + ILC3s may serve as efficient biomarkers for evaluating kidney function.