Structural and functional insights into transcription activation of the essential LysR-type transcriptional regulators.

The enormous LysR-type transcriptional regulators (LTTRs), which are diversely distributed amongst prokaryotes, play crucial roles in transcription regulation of genes involved in basic metabolic pathways, virulence and stress resistance. However, the precise transcription activation mechanism of these genes by LTTRs remains to be explored. Here, we determine the cryo-EM structure of a LTTR-dependent transcription activation complex comprising of Escherichia coli RNA polymerase (RNAP), an essential LTTR protein GcvA and its cognate promoter DNA. Structural analysis shows two N-terminal DNA binding domains of GcvA (GcvA_DBD) dimerize and engage the GcvA activation binding sites, presenting the -35 element for specific recognition with the conserved σ70R4. In particular, the versatile C-terminal domain of α subunit of RNAP directly interconnects with GcvA_DBD, σ70R4 and promoter DNA, providing more interfaces for stabilizing the complex. Moreover, molecular docking supports glycine as one potential inducer of GcvA, and single molecule photobleaching experiments kinetically visualize the occurrence of tetrameric GcvA-engaged transcription activation complex as suggested for the other LTTR homologs. Thus, a general model for tetrameric LTTR-dependent transcription activation is proposed. These findings will provide new structural and functional insights into transcription activation of the essential LTTRs.

Evaluation of the feeding safety of Moringa (Moringa oleifera L.) in the Sprague Dawley rat.

This study aimed to evaluate the safety of Moringa by comparing the effects of different gavage doses of Moringa. The general behavior, body weight, food intake, blood indexes, serum biochemical indexes, and histopathology of rats were used to determine the safety threshold and to provide a reference for the further development and use of Moringa as animal feed. 40 Sprague Dawley rats were selected and given transoral gavage for 28 consecutive days. The T1, T2 and T3 groups were observed for general behavior, body weight, and food intake. Blood and serum biochemical indices were quantified, and histopathology was performed to evaluate the effect and safety of Moringa. The results of the toxicological test showed that (1) Only T1 groups experienced diarrhea. (2) The body weight and food intake of rats in each group were normal compared with the control group. (3) The hematological and serum biochemical indices of rats in the T1 group were significantly different from those of CK but were in the normal range; (4) The results of microscopic examination of the heart, liver, spleen, lung, and kidney of rats in each group were normal, but inflammation occurred in stomach and jejunum of rats in the T1 group, but not in the ileum. The gastrointestinal tract of rats in the T2 and T3 groups were normal. (5) No abnormal death occurred in any of the treatment groups.The results of this study revealed that gavage of Moringa homogenate at a dose of 6 g/kg BW can cause diarrhea in rats. Although there is no pathological effect on weight, food intake, blood and serum biochemical indicators in rats, there are pathological textures in the gastrointestinal tissue caused by diarrhea. Therefore, the safety threshold of Moringa homogenate should be ≤ 3 g/kg BW.

Molecular characteristics and phylogenetic analysis of pigeon paramyxovirus type 1 isolates from pigeon meat farms in Shanghai (2009-2012).

The majority of pigeon paramyxovirus type 1 (PPMV-1) strains are generally non-pathogenic to chickens; however, they can induce severe illness and high mortality rates in pigeons, leading to substantial economic repercussions. The genomes of 11 PPMV-1 isolates from deceased pigeons on meat pigeon farms during passive monitoring from 2009 to 2012 were sequenced and analyzed using polymerase chain reaction and phylogenetic analysis. The complete genome lengths of 11 isolates were approximately 15,192 nucleotides, displaying a consistent gene order of 3'-NP-P-M-F-HN-L-5'. ALL isolates exhibited the characteristic motif of 112RRQKRF117 at the fusion protein cleavage site, which is characteristic of velogenic Newcastle disease virus. Moreover, multiple mutations have been identified within the functional domains of the F and HN proteins, encompassing the fusion peptide, heptad repeat region, transmembrane domains, and neutralizing epitopes. Phylogenetic analysis based on sequences of the F gene unveiled that all isolates clustered within genotype VI in class II. Further classification identified at least two distinct sub-genotypes, with seven isolates classified as sub-genotype VI.2.1.1.2.2, whereas the others were classified as sub-genotype VI.2.1.1.2.1. This study suggests that both sub-genotypes were implicated in severe disease manifestation among meat pigeons, with sub-genotype VI.2.1.1.2.2 displaying an increasing prevalence among Shanghai's meat pigeon population since 2011. These results emphasize the value of developing pigeon-specific vaccines and molecular diagnostic tools for monitoring and proactively managing potential PPMV-1 outbreaks.

Identification of UDP-glucuronosyltransferase (UGT) isoforms involved in the metabolism of Chlorophenols (CPs).

Chlorophenols (CPs) are a group of pollutants that pose a great threat to the environment, they are widely used in industrial and agricultural wastes, pesticides, herbicides, textiles, pharmaceuticals and plastics. Among CPs, pentachlorophenol was listed as one of the persistent organic pollutants (POPs) by the Stockholm convention. This study aims to identify the UDP-glucosyltransferase (UGT) isoforms involved in the metabolic elimination of CPs. CPs' mono-glucuronide was detected in the human liver microsomes (HLMs) incubation mixture with co-factor uridine-diphosphate glucuronic acid (UDPGA). HLMs-catalyzed glucuronidation metabolism reaction equations followed Michaelis-Menten or substrate inhibition type. Recombinant enzymes and chemical reagents inhibition experiments were utilized to phenotype the main UGT isoforms involved in the glucuronidation of CPs. UGT1A6 might be the major enzyme in the glucuronidation of mono-chlorophenol isomer. UGT1A1, UGT1A6, UGT1A9, UGT2B4 and UGT2B7 were the most important five UGT isoforms for metabolizing the di-chlorophenol and tri-chlorophenol isomers. UGT1A1 and UGT1A3 were the most important UGT isoforms in the catalysis of tetra-chlorophenol and pentachlorophenol isomers. Species differences were investigated using rat liver microsomes (RLMs), pig liver microsomes (PLMs), dog liver microsomes (DLMs), and monkey liver microsomes (MyLMs). All these results were helpful for elucidating the metabolic elimination and toxicity of CPs.

High-performance deep spiking neural networks via at-most-two-spike exponential coding.

Spiking neural networks (SNNs) provide necessary models and algorithms for neuromorphic computing. A popular way of building high-performance deep SNNs is to convert ANNs to SNNs, taking advantage of advanced and well-trained ANNs. Here we propose an ANN to SNN conversion methodology that uses a time-based coding scheme, named At-most-two-spike Exponential Coding (AEC), and a corresponding AEC spiking neuron model for ANN-SNN conversion. AEC neurons employ quantization-compensating spikes to improve coding accuracy and capacity, with each neuron generating up to two spikes within the time window. Two exponential decay functions with tunable parameters are proposed to represent the dynamic encoding thresholds, based on which pixel intensities are encoded into spike times and spike times are decoded into pixel intensities. The hyper-parameters of AEC neurons are fine-tuned based on the loss function of SNN-decoded values and ANN-activation values. In addition, we design two regularization terms for the number of spikes, providing the possibility to achieve the best trade-off between accuracy, latency and power consumption. The experimental results show that, compared to other similar methods, the proposed scheme not only obtains deep SNNs with higher accuracy, but also has more significant advantages in terms of energy efficiency and inference latency. More details can be found at https://github.com/RPDS2020/AEC.git.

LncRNA FOXD2-AS1 promotes the growth, invasion and migration of OSCC cells by regulating the MiR-185-5p/PLOD1/Akt/mTOR pathway.

Although lncRNAs are recognized to contribute to the development of oral squamous-cell carcinoma (OSCC), their exact function in invasion and cell migration is not clear. In this research, we explored the molecular and cellular mechanisms of FOXD2-AS1 in OSCC. Prognostic and bioinformatics analyses were used to test for the differential expression of FOXD2-AS1-PLOD1. Following FOXD2-AS1 suppression or overexpression, changes in cell viability were measured using the CCK-8 test; changes in cell migration and invasion abilities were measured using the migration and the Transwell assay. The expression of associated genes and proteins was found using Western blot and RT-qPCR. Analysis of luciferase reporter genes was done to look for regulatory connections between various molecules. The FOXD2-AS1-PLOD1 pair, which was highly expressed in OSCC, was analyzed and experimentally verified to be closely related to the prognosis of OSCC, and a nomogram model and correction curve were constructed. The inhibition of FOXD2-AS1 resulted in the reduction of cell activity, migration, invasion ability and changes in genes related to invasion and migration. In vivo validation showed that inhibition of FOXD2-AS1 expression slowed tumor growth, and related proteins changed accordingly. The experiments verified that FOXD2-AS1 negatively regulated miR-185-5 p and that miR-185-5 p negatively regulated PLOD1. In addition, it was found that the expression of PLOD1, p-Akt and p-mTOR proteins in OSCC cells was reduced by the inhibition of FOXD2-AS1, and FOXD2-AS1 and PLOD1 were closely related to the Akt/mTOR pathway. Increased expression of FOXD2-AS1 promotes OSCC growth, invasion and migration, which is important in part by targeting miR-185-5 p/PLOD1/Akt/mTOR pathway activity.

Resonant exchange of Chiral Majorana Fermions modulated by two parallel quantum dots.

Resonant exchange of the chiral Majorana fermions (MFs) that is coupled to two parallel Majorana zero modes (MZMs) or two parallel quantum dots (QDs) is investigated. We find that, in the two QDs coupling case, the resonant exchange for the chiral MFs is analogous to that in the MZM coupling case. We further propose a circuit based on topological superconductor (TSC), which is formed by the proximity coupling of a quantum anomalous Hall insulator (QAHI) and a s-wave superconductor, to observe the resonant exchange of chiral MFs pairs. The numerical calculations show that the resonant transmission of the chiral MFs can be adjusted by varying the coupling parameters. It is particularly noteworthy that, by only modulating the coupling strength between the two QDs, the resonant exchange may be switched on or off. By adding another MZM, the non-Abelian braidinglike operation can be realized. Therefore, our design scheme may provide another way for non-Abelian braiding operation of MFs and the findings may have potential application value in the realization of topological quantum computers.

Traditional, complementary and integrative medicine for fatigue post COVID-19 infection: A systematic review of randomized controlled trials.

Background: Chronic fatigue is a predominant symptom of post COVID-19 condition, or long COVID. We aimed to evaluate the efficacy and safety of Traditional, Complementary and Integrative Medicine (TCIM) for fatigue post COVID-19 infection. Methods: Ten English and Chinese language databases and grey literature were searched up to 12 April 2023 for randomized controlled trials (RCTs). Cochrane "Risk of bias" (RoB) tool was applied. Evidence certainty was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Effect estimates were presented as risk ratio (RR) or mean difference (MD) with 95% confidence interval (CI). Results: Thirteen RCTs with 1632 participants were included. One RCT showed that Bufei Huoxue herbal capsules reduced fatigue (n=129, MD -14.90, 95%CI -24.53 to -5.27), one RCT reported that Ludangshen herbal liquid lowered fatigue (n=184, MD -1.90, 95%CI -2.38 to -1.42), and the other one RCT shown that fatigue disappearance rate was higher with Ludangshen herbal liquid (n=184, RR 4.19, 95%CI 2.06 to 8.53). Compared to traditional Chinese medicine rehabilitation (TCM-rahab) alone, one RCT showed that fatigue symptoms were lower following Qingjin Yiqi granules plus TCM-rehab (n=388, MD -0.48, 95%CI -0.50 to -0.46). Due to concerns with RoB and/or imprecision, the certainty in this evidence was low to very low. No serious adverse events was reported. Conclusions: Limited evidence suggests that various TCIM interventions might reduce post COVID-19 fatigue. Larger, high quality RCTs of longer duration are required to confirm these preliminary findings. Study Registration: The protocol of this review has been registered at PROSPERO: CRD42022384136.

Nonadiabatic Field with Triangle Window Functions on Quantum Phase Space.

Recent progress on the constraint coordinate-momentum phase space (CPS) formulation of finite-state quantum systems has revealed that the triangle window function approach is an isomorphic representation of the exact population-population correlation function of the two-state system. We use the triangle window (TW) function and the CPS mapping kernel element to formulate a novel useful representation of discrete electronic degrees of freedom (DOFs). When it is employed with nonadiabatic field (NaF) dynamics, a new variant of the NaF approach (i.e., NaF-TW) is proposed. The NaF-TW expression of the population of any adiabatic state is always positive semidefinite. Extensive benchmark tests of model systems in both the condensed phase and gas phase demonstrate that the NaF-TW approach is able to faithfully capture the dynamical interplay between electronic and nuclear DOFs in a broad region, including where the states remain coupled all the time, as well as where the bifurcation characteristic of nuclear motion is important.

Association between household size and risk of incident dementia in the UK Biobank study.

Currently, the relationship between household size and incident dementia, along with the underlying neurobiological mechanisms, remains unclear. This prospective cohort study was based on UK Biobank participants aged ≥ 50 years without a history of dementia. The linear and non-linear longitudinal association was assessed using Cox proportional hazards regression and restricted cubic spline models. Additionally, the potential mechanisms driven by brain structures were investigated by linear regression models. We included 275,629 participants (mean age at baseline 60.45 years [SD 5.39]). Over a mean follow-up of 9.5 years, 6031 individuals developed all-cause dementia. Multivariable analyses revealed that smaller household size was associated with an increased risk of all-cause dementia (HR, 1.06; 95% CI 1.02-1.09), vascular dementia (HR, 1.08; 95% CI 1.01-1.15), and non-Alzheimer's disease non-vascular dementia (HR, 1.09; 95% CI 1.03-1.14). No significant association was observed for Alzheimer's disease. Restricted cubic splines demonstrated a reversed J-shaped relationship between household size and all-cause and cause-specific dementia. Additionally, substantial associations existed between household size and brain structures. Our findings suggest that small household size is a risk factor for dementia. Additionally, brain structural differences related to household size support these associations. Household size may thus be a potential modifiable risk factor for dementia.

Anti-inflammatory properties and characterization of water extracts obtained from Callicarpa kwangtungensis Chun using in vitro and in vivo rat models.

Callicarpa kwangtungensis Chun (CK) is a common remedy exhibits anti-inflammatory properties and has been used in Chinese herbal formulations, such as KangGongYan tablets. It is the main component of KangGongYan tablets, which has been used to treat chronic cervicitis caused by damp heat, red and white bands, cervical erosion, and bleeding. However, the anti-inflammatory effects of CK water extract remains unknown. This study assessed the anti-inflammatory effects of CK in vivo and in vitro, characterized its main components in the serum of rats and verified the anti-inflammatory effects of serum containing CK. Nitric oxide (NO), tumour necrosis factor α (TNF-α) and interleukin-6 (IL-6) release by RAW264.7 cells was examined by ELISA and Griess reagents. Inflammation-related protein expression in LPS-stimulated RAW264.7 cells was measured by western blotting. Furthermore, rat model of foot swelling induced by λ-carrageenan and a collagen-induced arthritis (CIA) rat model were used to explore the anti-inflammatory effects of CK. The components of CK were characterized by LC-MS, and the effects of CK-containing serum on proinflammatory factors levels and the expression of inflammation-related proteins were examined by ELISA, Griess reagents and Western blotting. CK suppressed IL-6, TNF-α, and NO production, and iNOS protein expression in LPS-stimulated RAW264.7 cells. Mechanistic studies showed that CK inhibited the phosphorylation of ERK, P38 and JNK in the MAPK signaling pathway, promoted the expression of IκBα in the NF-κB signaling pathway, and subsequently inhibited the expression of iNOS, thereby exerting anti-inflammatory effects. Moreover, CK reduced the swelling rates with λ-carrageenan induced foot swelling, and reduced the arthritis score and incidence in the collagen-induced arthritis (CIA) rat model. A total of 68 compounds in CK water extract and 31 components in rat serum after intragastric administration of CK were characterized. Serum pharmacological analysis showed that CK-containing serum suppressed iNOS protein expression and NO, TNF-α, and IL-6 release. CK may be an anti-inflammatory agent with therapeutic potential for acute and chronic inflammatory diseases, especially inflammatory diseases associated with MAPK activation.

Ophiocordyceps sinensis preparations combined with the renin-angiotensin system inhibitor for diabetic kidney disease treatment: an umbrella review of systematic reviews and network meta-analysis.

Aims: This study aimed to synthesize the evidence of the comparative effectiveness and safety of Ophiocordyceps sinensis (OS) preparations combined with renin-angiotensin system inhibitors (RASi) for diabetic kidney disease (DKD). Methods: Eight databases were searched from their inception to May 2023. Systematic reviews (SRs) of OS preparations combined with RASi for DKD were identified. Randomized controlled trials (RCTs) from the included SRs and additional searching were performed for data pooling. Cochrane risk-of-bias 2 (RoB 2) tool and AMSTAR 2 were used to evaluate the methodological quality of RCTs and SRs, respectively. A Bayesian network meta-analysis was performed to compare the add-on effect and safety of OS preparations for DKD. The certainty of evidence was graded using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Results: Fourteen SRs were included, whose methodological quality was assessed as high (1/14) or critically low (13/14). After combining additional searching, 157 RCTs were included, involving 13,143 participants. The quality of the RCTs showed some concerns (155/157) or high risk (2/157). Jinshuibao capsules and tablets, Bailing capsules and tablets, and Zhiling capsules were evaluated. Compared to RASi, adding either of the OS capsular preparations resulted in a decreased 24-h urinary total protein levels. OS preparations ranked differently in each outcome. Jinshuibao capsules plus RASi were beneficial in reducing urinary protein, serum creatinine, serum urea nitrogen, and blood glucose levels, with moderate-certainty evidence. No serious adverse events were observed after adding OS to RASi. Conclusion: Combining OS capsular preparations with RASi appeared to be associated with decreased urinary total protein levels in DKD patients. Further high-quality studies are needed to confirm. Systematic Review Registration: INPASY202350066.

Design, synthesis, and biological evaluation of novel sesquiterpene lactone derivatives as PKM2 activators with potent anti-ulcerative colitis activities.

Pyruvate kinase isoform 2 (PKM2) is closely related to the regulation of Th17/Treg balance, which is considered to be an effective strategy for UC therapy. Parthenolide (PTL), a natural product, only possesses moderate PKM2-activating activity. Thus, five series of PTL derivatives are designed and synthesized to improve PKM2-activated activities and anti-UC abilities. Through detailed structure optimization, B4 demonstrates potent T-cell anti-proliferation activity (IC50 = 0.43 µM) and excellent PKM2-activated ability (AC50 = 0.144 µM). Subsequently, through mass spectrometry analysis, B4 is identified to interact with Cys423 of PKM2 via covalent-bond. Molecular docking and molecular dynamic simulation results reveal that the trifluoromethoxy of B4 forms a stronger hydrophobic interaction with Ala401, Pro402, and Ile403. In addition, B4 has a significant effect only on Th17 cell differentiation, thereby regulating the Th17/Treg balance. The effect of B4 on Th17/Treg imbalance can be attributed to inhibition of PKM2 dimer translocation and suppression of glucose metabolism. Finally, B4 can notably ameliorate the symptoms of dextran sulfate sodium (DSS)-induced colitis in mouse model in vivo. Thus, B4 is confirmed as a potent PKM2 activator, and has the potential to develop as a novel anti-UC agent.

Alkyl Chains Tune Molecular Orientations to Enable Dual Passivation in Inverted Perovskite Solar Cells.

Nonradiative recombination losses occurring at the interface pose a significant obstacle to achieve high-efficiency perovskite solar cells (PSCs), particularly in inverted PSCs. Passivating surface defects using molecules with different functional groups represents one of the key strategies for enhancing PSCs efficiency. However, a lack of insight into the passivation orientation of molecules on the surface is a challenge for rational molecular design. In this study, aminothiol hydrochlorides with different alkyl chains but identical electron-donating (-SH) and electron-withdrawing (-NH3+) groups were employed to investigate the interplay between molecular structure, orientation, and interaction on perovskite surface. The 2-Aminoethane-1-thiol hydrochloride with shorter alkyl chains exhibited a preference of parallel orientations, which facilitating stronger interactions with the surface defects through strong coordination and hydrogen bonding. The resultant perovskite films following defect passivation demonstrate reduced ion migration, inhibition of nonradiative recombination, and more n-type characteristics for efficient electron transfer. Consequently, an impressive power conversion efficiency of 25% was achieved, maintaining 95% of its initial efficiency after 500 hours of continuous maximum power point tracking.

Mandibular Osteomyelitis as the Earliest Clinical Manifestation of Maxillary Sinus Lymphoma.

Extranodal natural killer/T-cell lymphoma is a distinct subtype of non-Hodgkin lymphoma that originates from natural killer cells or cytotoxic T cells. Its diagnosis is challenging due to the rarity and lack of awareness, especially in cases where osteomyelitis of the jawbone is the initial symptom. This paper reports a case of extranodal natural killer/T-cell lymphoma presenting primarily with oral ulcers. Through analyzing the clinical and pathological characteristics, differential diagnosis, treatment and prognosis, and reasons for misdiagnosis of the disease, this study aims to provide references for clinical diagnosis and treatment.

Perspective: Probing elasto-quantum materials with X-ray techniques and in situ anisotropic strain.

Anisotropic lattice deformation plays an important role in the quantum mechanics of solid state physics. The possibility of mediating the competition and cooperation among different order parameters by applying in situ strain/stress on quantum materials has led to discoveries of a variety of elasto-quantum effects on emergent phenomena. It has become increasingly critical to have the capability of combining the in situ strain tuning with X-ray techniques, especially those based on synchrotrons, to probe the microscopic elasto-responses of the lattice, spin, charge, and orbital degrees of freedom. Herein, we briefly review the recent studies that embarked on utilizing elasto-X-ray characterizations on representative material systems and demonstrated the emerging opportunities enabled by this method. With that, we further discuss the promising prospect in this rising area of quantum materials research and the bright future of elasto-X-ray techniques. .

Inhibition of LSD1 via SP2509 attenuated the progression of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial hyperplasia, pannus formation, and cartilage and bone destruction. Lysine-specific demethylase 1 (LSD1), an enzyme involved in transcriptional regulation, has an unclear role in synovial inflammation, fibroblast-like synoviocytes migration, and invasion during RA pathogenesis. In this study, we observed increased LSD1 expression in RA synovial tissues and in TNF-α-stimulated MH7A cells. SP2509, an LSD1 antagonist, directly reduced LSD1 expression and reversed the elevated levels of proteins associated with inflammation, apoptosis, proliferation, and autophagy induced by TNF-α. Furthermore, SP2509 inhibited the migratory capacity of MH7A cells, which was enhanced by TNF-α. In CIA models, SP2509 treatment ameliorated RA development, reducing the expression of pro-inflammatory cytokines and alleviating joint pathological symptoms. These findings underscore the significance of LSD1 in RA and propose the therapeutic potential of SP2509.

Lithium-Ion Conductive Coatings for Nickel-Rich Cathodes for Lithium-Ion Batteries.

Nickel (Ni)-rich cathodes are among the most promising cathode materials of lithium batteries, ascribed to their high-power density, cost-effectiveness, and eco-friendliness, having extensive applications from portable electronics to electric vehicles and national grids. They can boost the wide implementation of renewable energies and thereby contribute to carbon neutrality and achieving sustainable prosperity in the modern society. Nevertheless, these cathodes suffer from significant technical challenges, leading to poor cycling performance and safety risks. The underlying mechanisms are residual lithium compounds, uncontrolled lithium/nickel cation mixing, severe interface reactions, irreversible phase transition, anisotropic internal stress, and microcracking. Notably, they have become more serious with increasing Ni content and have been impeding the widespread commercial applications of Ni-rich cathodes. Various strategies have been developed to tackle these issues, such as elemental doping, adding electrolyte additives, and surface coating. Surface coating has been a facile and effective route and has been investigated widely among them. Of numerous surface coating materials, have recently emerged as highly attractive options due to their high lithium-ion conductivity. In this review, a thorough and comprehensive review of lithium-ion conductive coatings (LCCs) are made, aimed at probing their underlying mechanisms for improved cell performance and stimulating new research efforts.

Association of plasma ceramide with decline in kidney function in patients with type 2 diabetes.

Circulating ceramide levels are dysregulated in kidney disease. However their associations with rapid decline in kidney function (RDKF) and end-stage kidney disease (ESKD) in patients with type 2 diabetes (T2D) are unknown. In this prospective study of 1746 T2D participants, we examined the association of plasma ceramide Cer16:0, Cer18:0, Cer24:0 and Cer24:1 with RDKF, defined as an estimated glomerular filtration rate (eGFR) decline of 5ml/min/1.73m2/yr or greater, and ESKD defined as eGFR <15/min/1.73m2 for at least three months, on dialysis, or renal death at follow-up. We performed multivariable logistic and cox regression analyses adjusted for traditional cardio-renal risk factors, including baseline renal functions. During a median (interquartile range) follow-up period of 7.7 (4.7-8.9) years, 197 (11%) patients experienced RDKF. Ceramide Cer24:0 (odds ratio [OR]=0.71, 95%CI 0.56-0.90) and ratios Cer16:0/Cer24:0 (OR=3.54, 95%CI 1.70-7.35), Cer18:0/Cer24:0 (OR=1.89, 95%CI 1.10-3.25) and Cer24:1/Cer24:0 (OR=4.01, 95%CI 1.93-8.31) significantly associated with RDKF in multivariable analysis. 124 patients developed ESKD. The ratios Cer16:0/Cer24:0 (hazard ratio [HR]=3.10, 95%CI 1.44-6.64), and Cer24:1/Cer24:0 (HR=4.66, 95%CI 1.93-11.24) significantly associated with a higher risk of ESKD. The Cer24:1/Cer24:0 ratio improved risk discrimination for ESKD beyond traditional risk factors by small but statistically significant margin (Harrell C-index difference 0.01; P=0.022). A high ceramide risk score, constructed using individual ceramide level and ceramide ratios, also associated with RDKF (OR=2.28, 95%CI 1.26-4.13) compared to lower risk score. In conclusion, specific ceramide levels and their ratios are associated with RDKF and conferred an increased risk of ESKD, independently of traditional risk factors in patients with T2D.

Bacterial Sphingolipids Exacerbate Colitis by Inhibiting ILC3-derived IL-22 Production.

BACKGROUND & AIMS: Gut bacterial sphingolipids, primarily produced by Bacteroidetes, have dual roles as bacterial virulence factors and regulators of the host mucosal immune system, including regulatory T cells and iNKT cells. IBD patients display altered sphingolipids profiles in fecal samples. However, how bacterial sphingolipids modulate mucosal homeostasis and regulate intestinal inflammation remains unclear. METHODS: We utilized DSS-induced colitis in mice mono-colonized with Bacteroides fragilis strains expressing or lacking sphingolipids to assess the influence of bacterial sphingolipids on intestinal inflammation employing transcriptional, protein, and cellular analyses. Colonic explant and organoid were used to study the function of bacterial sphingolipids. Host mucosal immune cells and cytokines were profiled and characterized using flow cytometry, ELISA, and Western Blot, and cytokine function in vivo was investigated by monoclonal antibody injection. RESULTS: B. fragilis sphingolipids exacerbated intestinal inflammation. Mice mono-colonized with B. fragilis lacking sphingolipids exhibited less severe DSS-induced colitis. This amelioration of colitis was associated with increased production of interleukin-22 by ILC3. Mice colonized with B. fragilis lacking sphingolipids following DSS treatment showed enhanced epithelial STAT3 activity, intestinal cell proliferation, and antimicrobial peptide production. Protection against DSS colitis associated with B. fragilis lacking sphingolipids was reversed upon IL-22 blockade. Furthermore, bacterial sphingolipids restricted epithelial IL-18 production following DSS treatment and interfered with IL-22 production by a subset of ILC3 cells expressing both IL-18R and MHC II. CONCLUSION: B. fragilis-derived sphingolipids exacerbate mucosal inflammation by impeding epithelial IL-18 expression and concomitantly suppressing the production of IL-22 by ILC3 cells.