Guild-level signature of gut microbiome for diabetic kidney disease.

Current microbiome signatures for chronic diseases such as diabetic kidney disease (DKD) are mainly based on low-resolution taxa such as genus or phyla and are often inconsistent among studies. In microbial ecosystems, bacterial functions are strain specific, and taxonomically different bacteria tend to form co-abundance functional groups called guilds. Here, we identified guild-level signatures for DKD by performing in-depth metagenomic sequencing and conducting genome-centric and guild-based analysis on fecal samples from 116 DKD patients and 91 healthy subjects. Redundancy analysis on 1,543 high-quality metagenome-assembled genomes (HQMAGs) identified 54 HQMAGs that were differentially distributed among the young healthy control group, elderly healthy control group, early-stage DKD patients (EDG), and late-stage DKD patients (LDG). Co-abundance network analysis classified the 54 HQMAGs into two guilds. Compared to guild 2, guild 1 contained more short-chain fatty acid biosynthesis genes and fewer genes encoding uremic toxin indole biosynthesis, antibiotic resistance, and virulence factors. Guild indices, derived from the total abundance of guild members and their diversity, delineated DKD patients from healthy subjects and between different severities of DKD. Age-adjusted partial Spearman correlation analysis showed that the guild indices were correlated with DKD disease progression and with risk indicators of poor prognosis. We further validated that the random forest classification model established with the 54 HQMAGs was also applicable for classifying patients with end-stage renal disease and healthy subjects in an independent data set. Therefore, this genome-level, guild-based microbial analysis strategy may identify DKD patients with different severity at an earlier stage to guide clinical interventions. IMPORTANCE: Traditionally, microbiome research has been constrained by the reliance on taxonomic classifications that may not reflect the functional dynamics or the ecological interactions within microbial communities. By transcending these limitations with a genome-centric and guild-based analysis, our study sheds light on the intricate and specific interactions between microbial strains and diabetic kidney disease (DKD). We have unveiled two distinct microbial guilds with opposite influences on host health, which may redefine our understanding of microbial contributions to disease progression. The implications of our findings extend beyond mere association, providing potential pathways for intervention and opening new avenues for patient stratification in clinical settings. This work paves the way for a paradigm shift in microbiome research in DKD and potentially other chronic kidney diseases, from a focus on taxonomy to a more nuanced view of microbial ecology and function that is more closely aligned with clinical outcomes.

Genome-wide analysis of long non-coding RNAs (lncRNAs) in tea plants (Camellia sinensis) lateral roots in response to nitrogen application.

Tea (Camellia sinensis) is one of the significant cash crops in China. As a leaf crop, nitrogen supply can not only increase the number of new shoots and leaves but also improve the tenderness of the former. However, a conundrum remains in science, which is the molecular mechanism of nitrogen use efficiency, especially long non-coding RNA (lncRNA). In this study, a total of 16,452 lncRNAs were identified through high-throughput sequencing analysis of lateral roots under nitrogen stress and control conditions, of which 9,451 were differentially expressed lncRNAs (DE-lncRNAs). To figure out the potential function of nitrogen-responsive lncRNAs, co-expression clustering was employed between lncRNAs and coding genes. KEGG enrichment analysis revealed nitrogen-responsive lncRNAs may involve in many biological processes such as plant hormone signal transduction, nitrogen metabolism and protein processing in endoplasmic reticulum. The expression abundance of 12 DE-lncRNAs were further verified by RT-PCR, and their expression trends were consistent with the results of RNA-seq. This study expands the research on lncRNAs in tea plants, provides a novel perspective for the potential regulation of lncRNAs on nitrogen stress, and valuable resources for further improving the nitrogen use efficiency of tea plants.

Targeting FABP4 in elderly mice rejuvenates liver metabolism and ameliorates aging-associated metabolic disorders.

INTRODUCTION: Aging is characterized by progressive metabolic dyshomeostasis that increases morbidity and mortality. Solutions for optimizing healthy aging are challenged by lacking appropriate biomarkers. Moreover, druggable targets to rejuvenate the aging-associated metabolic phenotypes remain unavailable. METHODS: Proteomics analysis was performed in a cohort of young and elderly adults. Circulating levels of insulin-like growth factor 1 (IGF-1) and fatty acid binding protein 4 (FABP4) were evaluated by ELISA. FABP4 was silenced in elderly mice by adeno-associated virus. Metabolic activities were measured by metabolic cages. Cognitive function was evaluated by Morris water maze. Glucose and lipid metabolism were evaluated by biochemistry assays with blood samples. RNA-seq in mouse liver was performed for transcriptome analysis. RESULTS: Among 9 aging-sensitive proteins shared by both male and female, FABP4 was identified as a reliable aging biomarker in both human and mouse. Silencing FABP4 in elderly mice significantly rejuvenated the aging-associated decline in metabolic activities. FABP4 knockdown reversed the aging-associated metabolic disorders by promoting degradation of cholesterol and fatty acids, while suppressing gluconeogenesis. Transcriptome analysis revealed a restoration of the pro-aging gene reprogramming towards inflammation and metabolic disorders in the liver after FABP4 knockdown. FABP4 overexpression promoted human LO2 cell senescence. Moreover, administration of an FABP4 inhibitor BMS309403 delivered metabolic benefits in elderly mice. CONCLUSION: Our findings demonstrate FABP4 as a reliable aging biomarker as well as a practicable target to improve healthy aging in the elderly.

Vertical transmission of the gut microbiota influences glucose metabolism in offspring of mice with hyperglycaemia in pregnancy.

BACKGROUND: Hyperglycaemia in pregnancy (HIP) is a common metabolic disorder that not only poses risks to maternal health but also associates with an increased risk of diabetes among offspring. Vertical transmission of microbiota may influence the offspring microbiome and subsequent glucose metabolism. However, the mechanism by which maternal gut microbiota may influence glucose metabolism of the offspring remains unclear and whether intervening microbiota vertical transmission could be used as a strategy to prevent diabetes in the offspring of mothers with HIP has not been investigated. So we blocked vertical transmission to investigate its effect on glucose metabolism in the offspring. RESULTS: We established a murine HIP model with a high-fat diet (HFD) and investigated the importance of vertical transmission of gut microbiota on the glucose metabolism of offspring via birth and nursing by blocking these events through caesarean section (C-section) and cross-fostering. After weaning, all offspring were fed a normal diet. Based on multi-omics analysis, biochemical and transcriptional assays, we found that the glucometabolic deficits in the mothers were subsequently 'transmitted' to the offspring. Meanwhile, the partial change in mothers' gut microbial community induced by HIP could be transmitted to offspring, supported by the closed clustering of the microbial structure and composition between the offspring and their mothers. Further study showed that the microbiota vertical transmission was blocked by C-section and cross-fostering, which resulted in improved insulin sensitivity and islet function of the offspring of the mothers with HIP. These effects were correlated with changes in the relative abundances of specific bacteria and their metabolites, such as increased relative abundances of Bifidobacterium and short-chain fatty acids. In particular, gut microbial communities of offspring were closely related to those of their foster mothers but not their biological mothers, and the effect of cross-fostering on the offspring's gut microbiota was more profound than that of C-section. CONCLUSION: Our study demonstrates that the gut microbiota transmitted via birth and nursing are important contributors to the glucose metabolism phenotype in offspring. Video Abstract.

Nontoxic Tb3+-induced hyaluronic nano-poached egg aggregates for colorimetric and luminescent detection of Fe3+ ions.

This study demonstrates that a luminescent Tb3+ complex with green emission can be complexed with hyaluronic (hya) to form nanoparticles. The structure of complexation is composed of a Tb(acac)2phen core with a hya surface, similar to those of the nano-poached eggs. What makes the structure unique is that Tb(acac)2phen and hya are connected by chemical bonds. To confirm their utility, we illustrate that the luminescence is rapidly and selectively quenched in the presence of Fe3+. Initial cytotoxicity experiments with human liver carcinoma cells show that the luminescent lanthanide complexes are cytotoxic, however, complexing lanthanides to hya renders them cytocompatible. The new complex integrates the advantages of superior lanthanide luminescence, the unique shape of nano-poached eggs, compatibility with aqueous systems, and cytocompatibility. Tb3+-induced hyaluronic nano-poached eggs (THNE) can, therefore, be used for Fe3+ detection in aqueous systems.

Crtc1 Deficiency Causes Obesity Potentially via Regulating PPARγ Pathway in White Adipose.

Obesity is characterized by excessive fat accumulation and associated with glucose and lipid metabolism disorders. Crtc1, a transcription cofactor regulating CREB activity, has been involved in the pathogenesis of metabolic syndrome; however, the underlying mechanism remains under debate. Here we generated a Crtc1-/- mouse line using the CRISPR/Cas9 system. Under normal feeding conditions, Crtc1-/- mice exhibited an obese phenotype resultant from the abnormal expansion of the white adipocytes. The development of obesity in Crtc1-/- mice is independent of alterations in food intake or energy expenditure. Moreover, Crtc1-/- mice were more prone to insulin resistance and dyslipidemia, as evidenced by higher levels of plasma glucose, insulin and FABP4 than wildtype mice. Transcriptome analysis in liver and epididymal white adipose tissue (eWAT) showed that the fat accumulation caused by Crtc1 deletion was mainly related to lipid metabolism in adipose tissue, but not in liver. GSEA and KEGG analysis identified PPAR pathway to be of the highest impact on lipid metabolism in eWAT. This regulation was independent of a direct interaction between CRTC1 and PPARγ. Our findings demonstrate a crucial role of Crtc1 in regulating lipid metabolism in adipose during development, and provide novel insights into obesity prevention and therapeutics.

The association between serum uric acid and diabetic complications in patients with type 2 diabetes mellitus by gender: a cross-sectional study.

BACKGROUND: The relationship between serum uric acid (SUA) and several diabetic complications or co-morbidities remains a matter of debate. The study aims to explore the association between SUA levels and the prevalence of non-alcoholic fatty liver disease (NAFLD), diabetic retinopathy (DR), diabetic nephropathy (DN) and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM). METHODS: A total of 2,809 participants (1,784 males and 1,025 females) were included in this cross-sectional study. Clinical characteristics and the prevalence of each of the four diseases were analyzed based on gender-specific quartiles of SUA levels. The Pearson correlation analysis and linear-regression analysis were used to access the correlation between SUA levels and clinical characteristics. Furthermore, a binary logistic regression analysis was carried out to determine whether SUA was an independent risk factor for each of the four complications. RESULTS: SUA levels were positively correlated to BMI, BUN, Scr and TG, but negatively associated with eGFR, HDL, FBG, 2h-PG and HbA1c% for the patients with T2DM. The prevalence of NAFLD and DN, but not DR or DPN, were increased with SUA levels from the first to the fourth quartile. Binary logistic regression further disclosed that SUA was an independent risk factor for NAFLD (ORs Male = 1.002, ∗ P = 0.0013; ORs Female = 1.002, ∗ P = 0.015) and DN (ORs Male = 1.006, ∗ P < 0.001; ORs Female = 1.005, ∗ P < 0.001), but not for DR and DPN. After adjustment for the confounders, SUA levels were significantly associated with NAFLD within the 3rd (ORs = 1.829, P = 0.004) and 4th quartile (ORs = 2.064, P = 0.001) for women, but not independently associated with SUA for man. On the other hand, our results revealed increased prevalence of DN for SUA quartile 2 (ORs = 3.643, P = 0.039), quartile 3 (ORs = 3.967, P = 0.024) and quartile 4 (ORs = 9.133, P < 0.001) in men; however, SUA quartiles were significantly associated with DN only for quartile 4 (ORs = 4.083, P = 0.042) in women. CONCLUSION: For patients with T2DM, elevated SUA concentration is an independent risk factor for the prevalence of NAFLD and DN after adjustment for other indicators, but not DR or DPN.

Verapamil Ameliorates Hepatic Metaflammation by Inhibiting Thioredoxin-Interacting Protein/NLRP3 Pathways.

Activation of thioredoxin-interacting protein (TXNIP)/nod-like receptor protein 3 (NLRP3) inflammasome plays a critical role in pathogenesis of non-alcoholic fatty liver disease. This study investigated the protective effects of verapamil on hepatic metaflammation in a rodent model of high-fat (HF) diet-induced obesity (DIO). DIO was induced in a subset of mice provided with HF diet (45% kcal fat). After 10 weeks of HF diet, verapamil was administered by intraperitoneal injection. The experimental groups included the following: (1) normal diet group, (2) normal diet + treatment with verapamil (VER) group, (3) HF control group, (4) HF+VER (25 mg/kg/day) group. After 1 week of each treatment, blood and liver tissues were collected, and glucose control, serum triglyceride (TG) level, inflammation, and TXNIP/NLRP3 inflammasome were analyzed. Verapamil administration caused no alteration in food intake. HF diet impaired glucose control and increased body weight and serum TG levels. Hepatic inflammation was aggravated in HF-fed mice, as demonstrated by increased levels of pro-inflammatory markers interleukin-1ß (IL-1ß) and IL-18 in the liver. On the other hand, verapamil administration significantly improved glucose control, body weight, and serum TG levels. Verapamil treatment also reduced pro-inflammatory marker levels. These improvements were accompanied by alterations in activation of TXNIP/NLRP3 inflammasome. The observed results demonstrate that verapamil ameliorates hepatic metaflammation by inhibiting TXNIP/NLRP3 pathways.

Sodium butyrate mitigates type 2 diabetes by inhibiting PERK-CHOP pathway of endoplasmic reticulum stress.

Sodium butyrate (NaB), a histone deacetylase (HDAC) inhibitors, has been reported to attenuate hyperglycemia in rats. Our objective was to explore the effect and underlying mechanism of NaB on islet ß-cell dysfunction and apoptosis in type 2 diabetic (T2DM) rats. T2DM models were induced by the combination of streptozotocin (STZ, 40 mg/kg) and high-fat-diet, while NaB (500 mg/kg/d) was intraperitoneally injected for 6 weeks in experimental groups. Our results suggested NaB mitigated hyperglycemia, lowered the levels of serum cholestenone (TC) and low-density lipoprotein (LDL-c), prevented body weight loss, and enhanced insulin resistance and glucose tolerance. NaB also improved diabetes-induced histological alteration of islet and functional damage; moreover, results of TUNEL and western blotting indicated NaB alleviated ß-cell apoptosis. Further research showed NaB down-regulated the expression of endoplasmic reticulum stress (ERS) related proteins, including phosphorylated type I transmembrane ER-resident protein kinase (p-PERK), phosphorylated eukaryotic initiation factor 2α (p-eIF2α), activating transcription factor (ATF4) and CCAAT/enhancer-binding protein homologous protein (CHOP). Consequently, NaB mitigates type 2 diabetes by inhibiting PERK-CHOP pathway of ERS.

Sall2 knockdown exacerbates palmitic acid induced dysfunction and apoptosis of pancreatic NIT-1 beta cells.

Spalt-like (Sall) proteins are a class of transcription factors. The role of Sall2 in beta cells remain poorly understood. Here, we aimed to explore whether Sall2 involved in lipotoxicity-mediated dysfunction and apoptosis in pancreatic NIT-1 beta cells. Our results showed that high concentrations of palmitic acid (PA) led to impaired cell viability and decreased Sall2 expression in NIT-1 cells. Knocking down of Sall2 in NIT-1 cells resulted in increased sensitivity to lipotoxicity and caused higher rates of cell apoptosis following PA treatment. Additionally, Sall2 Knockdown impaired insulin synthesis and secretion in response to glucose. Further research indicated Sall2 knockdown attenuate antioxidant capacity and decreased expression level of Peroxiredoxin 2 in NIT-1 cells. These finding implicate that Sall2 may play a significant role in NIT-1 cell function and cell apoptosis under lipotoxic conditions. Therefore, the study of Sall2 in NIT-1 cells provided a new perspective for molecular mechanism of lipotoxicity mediating dysfunction and apoptosis of beta cells.

The association between elevated serum uric acid levels and islet ß-cell function indexes in newly diagnosed type 2 diabetes mellitus: a cross-sectional study.

BACKGROUND: Serum uric acid (UA) has been reported as a risk factor for type 2 diabetes mellitus (T2DM). However, whether serum UA is associated with insulin resistance and insulin secretion, and the effect of gender on it in the case of the existed association, both remain undefined. METHODS: A cross-sectional study was designed and performed, which enrolled a total of 403 newly diagnosed T2DM patients (mean age, 50.21 ± 13.34 years (62.5% males)). Clinical characteristics and islet function indexes of all participants were analyzed based on gender-specific tertiles of serum UA levels. In addition, multiple linear regression analysis was conducted to investigate covariates associated with islet function indexes. RESULTS: The mean levels of serum UA were 331.05 µmol/L (interquartile range (IQR): 60.6, 400.9 µmol/L) and 267.9 µmol/L (IQR: 204.7, 331.9 µmol/L) in men and women, respectively. The values of insulin secretion indexes involving AUCins30/glu30, AUCins120/glu120 and total insulin disposition index (DI120) in females were significantly higher than those in males. Apart from the homeostasis model assessment insulin resistance of men, serum UA was positively associated with insulin secretion and insulin resistance indexes both in men and women. Multivariable linear regression analysis showed serum UA exerted an independent impact on insulin secretion in females, but not on insulin resistance. In males, islet function was simultaneously affected by serum UA age, body mass index (BMI), and serum lipids. CONCLUSION: Serum UA harbored a positive correlation with insulin secretion and insulin resistance indexes in newly diagnosed T2DM patients, which was influenced by gender, BMI, serum lipids. Hence, serum UA may be considered as a predictor for islet function in clinical practice.

TAp63 is correlated with chronic inflammation in patients with newly diagnosed type 2 diabetes mellitus.

AIMS: To investigate TAp63 expression in patients with type 2 diabetes mellitus (T2DM) and the potential correlations between TAp63 and proinflammatory cytokines production and other clinical parameters. METHODS: Peripheral blood mononuclear cells (PBMCs) and plasma were collected from 72 T2DM (cases) and 72 healthy subjects (controls). Fasting blood glucose (FBG), fasting insulin (FIN) and a blood lipid profile were measured. The homeostasis model assessment (HOMA) was used to estimate insulin resistance (IR). Plasma tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were determined. PBMCs isolated from healthy subjects were cultured with or without 33.3 mmol/l glucose or 0.5 mmol/l palmitic acid (PA) for 6 h, 24 h, 48 h, and 72 h. The expression of TAp63 at mRNA and protein levels in PBMCs was analyzed using real-time qRT-PCR and western blots, respectively. RESULTS: TAp63 expression was significantly lower in T2DM patients compared with that of the controls. In addition, TAp63 expression showed a negative correlation with FBG, FIN, HbA1c, HOMA-IR, FFAs, TNF-α, and IL-6 levels. Treatment with 33.3 mmol/l glucose or 0.5 mmol/l PA increased TAp63 expression in the cultured PBMCs. CONCLUSIONS: TAp63 level may be correlated with chronic inflammatory state and perturbed glucose and lipid metabolism in T2DM.

Ratiometric optical sensor for high-resolution imaging of pH with low cross-talk.

We synthesize lipophilic, highly efficient, and pH-insensitive oleic acid-modified quantum dots (QDs) with maximum emission at a wavelength of 628 nm. The pH sensing film is fabricated by encapsulating 5-hexadecanoylamino-fluorescein and QDs as the reference in D4-hydromed and plasticized polystyrene. Using a light-emitting diode with a central wavelength of 410 nm as an excitation source, it is shown that the emission wavelengths of the pH sensitive indicator and reference dye have no spectral overlap and match respectively the channels of a 3CCD (RGB) camera with low cross-talk. A series of validation experiments shows that this ratiometric pH optode has good properties of high sensitivity, long-term stability, and photostability. It had a fast response time of <20 s when going from pH 6.3 to pH 8.0. The pH images suggest that the proposed ratiometric pH-sensing approach has great advantage and promise for field applications.

Wogonin mitigates nonalcoholic fatty liver disease via enhancing PPARα/AdipoR2, in vivo and in vitro.

Wogonin has been reported to attenuate hyperglycemia in diabetic mice via anti-adipogenic effect on adipocytes. The potential therapeutic role of wogonin in nonalcoholic fatty liver disease (NAFLD) remains obscure. The aim of the present study was to explore the protective effect of wogonin on NAFLD mice and cultured NCTC 1469 cells exposed to palmitate. Wogonin supplementation significantly improved metabolic parameters in NAFLD mice, including body weight, blood glucose, insulin resistance, adiponectin, blood lipids, aminotransferases and hepatic histopathology. Further research in liver tissues from NAFLD mice and NCTC 1469 cells stressed by lipotoxicity showed wogonin treatment reduced inflammatory response by lowering interleukin-6 (IL-6) and tumor necrosis factor α (TNFα), alleviated oxidative stress by preventing the accumulation of oxidative product malondialdehyde (MDA) and strengthening the anti-oxidative capacity of glutathione (GSH), Superoxide Dismutase (SOD) and Glutathione Peroxidase (GPX). In addition, wogonin repaired the lipotoxicity-induced decline of peroxisome proliferator- activated receptor α (PPARα) and adiponectin receptor 2 (AdipoR2) in hepatocytes, in vivo and in vitro. Knock-down of PPARα abolished the protective effect of wogonin on NCTC 1469 cells, including the up-regulation of AdipoR2. Taken together, the current study demonstrated wogonin might be a potential therapeutic agent for NAFLD via up-regulation of hepatic PPARα/AdipoR2.

Effects of probiotics supplement in patients with type 2 diabetes mellitus: A meta-analysis of randomized trials. / Efectos del suplemento de probióticos en pacientes con diabetes mellitus tipo 2: metaanálisis de ensayos aleatorizados.

BACKGROUND AND OBJECTIVE: To objectively evaluate the effects of probiotics supplement on glycemic control and lipid metabolism in patients with type 2 diabetes mellitus (T2DM). MATERIAL AND METHODS: The randomized controlled trials (RCTs) with regard to the probiotics or synbiotics for the treatment of T2DM were collected through retrieving 5 databases from their establishment to March 2016. After study selection, quality assessment and data extraction were performed by 2 authors independently; and STATA software was used for statistical analysis. The level of evidence was evaluated by applying the GRADE system. RESULTS: Twelve RCTs involving 770 participants were enrolled. The results of the meta-analysis showed that probiotics could significantly reduce fasting blood glucose by -11.27mg/dL (95% CI -21.76 to -0.79; P<.001) and serum insulin concentration by -2.36µU/mL (95% CI -4.01 to -0.72; P=.005), but with no significant reduction on HbA1c (-0.19%; 95% CI -0.49 to 0.12; P=.23). Probiotics could significantly reduce HOMA-IR of T2DM patients (-1.05; 95% CI -1.52 to -0.59; P<.001). Nevertheless, the effect on QUICKI was negligible (0.00; 95% CI -0.00 to 0.01; P=.27). Results also confirmed the significant lowering effect of probiotics on total cholesterol (-8.49mg/dL; 95% CI -15.24 to -1.73; P=.014) and triglycerides (TG; -23.66mg/dL; 95% CI -40.26 to -7.05; P<.001), as well as the elevating effect on HDL-c (3.92mg/dL; 95% CI 2.14 to5.7; P<.01). However, there was no significant change on LDL-c (-0.84mg/dL; 95% CI -5.84 to 4.17; P=.75). Subgroup analysis was conducted for 2 outcomes, that is, serum insulin concentration and TG, whose heterogeneity was too high. The results showed multiple species of probiotics had stronger reduction effect on serum insulin concentration (-3.32µU/mL; 95% CI -5.89 to-0.75; P=.001) and TG (-25.94mg/dL; 95% CI -65.33 to 13.44; P<.001). In addition, it also suggested that only the duration of treatment for≥8 weeks could significantly reduce TG by -24.47mg/dL (95% CI -40.15 to -8.78; P=.001). The duration of treatment for<8 weeks didn't result in significant reduction on TG (-4.31mg/dL; 95% CI -37.69 to 29.06; P=.8). Finally, all the evidences were at moderate and low levels according to the GRADE system. CONCLUSION: As a kind of the potential biotherapeutics in the management of T2DM, probiotics can improve glucose control and lipid metabolism.