Melatonin inhibits circadian gene DEC1 and TLR2/MyD88/NF-κB signaling pathway to alleviate renal injury in type 2 diabetic mice.

BACKGROUND: Diabetic Kidney Disease (DKD) is a complex disease associated with circadian rhythm and biological clock regulation disorders. Melatonin (MT) is considered a hormone with renal protective effects, but its mechanism of action in DKD is unclear. METHODS: We used the GSE151325 dataset from the GEO database for differential gene analysis and further explored related genes and pathways through GO and KEGG analysis and PPI network analysis. Additionally, this study used a type 2 diabetes db/db mouse model and investigated the role of melatonin in DKD and its relationship with clock genes through immunohistochemistry, Western blot, real-time PCR, ELISA, chromatin immunoprecipitation (ChIP), dual-luciferase reporter technology, and liposome transfection technology to study DEC1 siRNA. RESULTS: Bioinformatics analysis revealed the central position of clock genes such as CLOCK, DEC1, Bhlhe41, CRY1, and RORB in DKD. Their interaction with key inflammatory regulators may reveal melatonin's potential mechanism in treating diabetic kidney disease. Further experimental results showed that melatonin significantly improved the renal pathological changes in db/db mice, reduced body weight and blood sugar, regulated clock genes in renal tissue, and downregulated the TLR2/MyD88/NF-κB signaling pathway. We found that the transcription factor DEC1 can bind to the TLR2 promoter and activate its transcription, while CLOCK's effect is unclear. Liposome transfection experiments further confirmed the effect of DEC1 on the TLR2/MyD88/NF-κB signaling pathway. CONCLUSION: Melatonin shows significant renal protective effects by regulating clock genes and downregulating the TLR2/MyD88/NF-κB signaling pathway. The transcription factor DEC1 may become a key regulatory factor for renal inflammation and fibrosis by activating TLR2 promoter transcription. These findings provide new perspectives and directions for the potential application of melatonin in DKD treatment.

The presence of exudative thickening of Bowman's capsule predict poor prognosis in diabetic kidney disease.

BACKGROUND: The relationship between Bowman's capsule thickening and progression of diabetic kidney disease (DKD) remains uncertain. METHODS: Renal biopsy specimens from 145 DKD patients and 20 control subjects were evaluated for Bowman's capsule thickness. Immunohistochemical staining assessed col4α2, laminin ß1, and albumin expression. In a discovery cohort of 111 DKD patients with eGFR ≥ 30 ml/min/1.73 m2, thickening was classified as fibrotic or exudative. The composite endpoint included CKD stage 5, dialysis initiation, and renal disease-related death. Prognosis was analyzed using Kaplan-Meier and Cox regression analyses. Two validation cohorts were included. RESULTS: Three types of thickening were observed: fibrotic, exudative, and periglomerular fibrosis. Parietal epithelial cell matrix protein accumulation contributed to fibrotic thickening, while albumin was present in exudative thickening. Bowman's capsule was significantly thicker in DKD patients (5.74 ± 2.09 µm) compared to controls (3.38 ± 0.43 µm, P < 0.01). In discovery cohort, the group of exudative thickning had a poorer prognosis(median time 20 months vs 57 months, P = 0.000). Cox multivariate analysis revealed that exudative thickening of Bowman's capsule were associated with a poor prognosis. The validation cohorts confirmed the result. CONCLUSIONS: Various mechanisms contribute to Bowman's capsule thickening in DKD. The proportion of exudative thickening may serve as a valuable prognostic indicator for DKD patients.

Association of dietary live microbe intake with diabetic kidney disease in patients with type 2 diabetes mellitus in US adults: a cross-sectional study of NHANES 1999-2018.

AIMS: Several studies have reported dietary microorganisms' beneficial effects on human health. We aimed to detect the potential association between dietary live microbe intake and diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM) through a cross-sectional analysis of the National Health and Nutrition Examination Survey from 1999 to 2018. METHODS: According to the Sanders classification system of dietary live microbes, the study participants were divided into three groups: low, medium, and high live microbe groups. In patients with T2DM, DKD was assessed by glomerular filtration rate (< 60 mL/min/1.73 m2 using the Chronic Kidney Disease Epidemiology Collaboration algorithm), proteinuria (urinary albumin to creatinine ratio ≥ 30 mg/g), or both. Weighted univariate and multivariate logistic regression and subgroup analyses were conducted to investigate the independent association between dietary live microbe and DKD. RESULTS: The study included 3836 participants, of whom 1467 (38.24%) had DKD for the diagnosis. Our study demonstrated that participants in the high dietary live microbe group were more likely to be older, female, non-Hispanic White, have higher education levels, have a lower prevalence of smoking, have a high poverty-income ratio, have higher energy intake, lower haemoglobin (HbA1c) and serum creatinine levels, and lower risk of progression. After adjustment for covariates, patients in the high dietary live microbe group had a low prevalence of DKD, whereas no significant association with DKD was found between the medium and low dietary live microbe groups. No statistically significant interaction was observed in all subgroup analyses except for HbA1c (p for interaction < 0.05). CONCLUSIONS: Our results indicate that high dietary live microbe intake was associated with a low DKD prevalence.

GLIS1 alleviates cell senescence and renal fibrosis through PGC1-α mediated mitochondrial quality control in kidney aging.

Mitochondrial dysfunction is implied as a crucial factor in age-related chronic kidney disease. It is confirmed that Gli-like transcription factor 1 (GLIS1) is involved in age-related renal fibrosis, however, the correlation between mitochondrial disturbances and GLIS1-driven kidney aging are not clearly clarified. Thus, we investigated the regulatory mechanism of GLIS1 in the homeostasis of mitochondrial quality control both in vivo and in vitro. The lower expression of GLIS1 was identified in natural and accelerated kidney aged models, accompanied by the dysfunctions of mitochondrial quality control, including enhanced mitochondrial fission, reduced mitochondrial biogenesis and mitophagy, whereas, GLIS1 could maintain mitochondrial stability by interacting with peroxisome proliferator-activated receptor γ coactivator-1α (PGC1-α). Additionally, the over-expressed GLIS1 inhibited extracellular matrix accumulation and alleviated renal fibrosis while siGLIS1 inhibited PGC1-α transcription, as well as affecting its mitochondria-protective functions. Collectively, we demonstrated that GLIS1 mediated mitochondrial quality control through targeting PGC1-α in kidney aging, which might be a promising therapeutic target for attenuating cell senescence and age-related renal fibrosis.

The relevance of the non-invasive biomarkers lncRNA GAS5/miR-21 ceRNA regulatory network in the early identification of diabetes and diabetic nephropathy.

BACKGROUND: To investigate the diagnostic value of serum lncRNA growth arrest-specific transcript 5 (lncRNA GAS5) and microRNA-21 (miR-21) in patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN), and elucidate their roles in the pathogenesis. METHODS: A microarray technology was used asses lncRNA GAS5 and miR-21 expression profiles in non-anticoagulant blood from 44 patients including T2DM without DN group (DM), T2DM with DN group (DN), and healthy controls group (N), followed by real-time PCR validation. Logistic regression and receiver operating characteristic (ROC) curves were applied to evaluate the clinical indicators among normal, T2DM, and DN patients. RESULTS: The serum lncRNA GAS5 expression in T2DM and DN patients was significantly down-regulated compared with the N group, while the expression of miR-21 was significantly up-regulated (all P < 0.05). Fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) were negatively correlated with serum lncRNA GAS5, and FBG was independently correlated with serum lncRNA GAS5. Urinary microalbumin, total cholesterol (TC), creatinine (Cr), urea, and systolic blood pressure (SBP) were significantly positively correlated with serum miR-21. Glomerular filtration rate (GFR) and albuminuria (ALB) were negatively correlated with serum miR-21, and ALB was independently correlated with serum miR-21. Serum lncRNA GAS5, miR-21 and lncRNA GAS5/miR-21 showed good diagnostic efficiency as the "diagnostic signature" of T2DM and DN. CONCLUSION: The lncRNA GAS5/miR-21 diagnostic signature may be a more effective non-invasive biomarker for detecting T2DM. In addition, miR-21 alone may be a more accurate serum biomarker for the early screening of DN patients.

Leuconostoc mesenteroides WHH1141 ameliorates ovalbumin-induced food allergy in mice.

Food allergy (FA) is acknowledged as a significant public health and food safety issue, due to its manifestation as an amplified immune reaction to food antigens. Recently, probiotics within Lactobacillus and Bifidobacterium have been highlighted as a promising strategy against allergic disease by modulating the balance of Th1/Th2 responses. However, the allergy-alleviating effects of probiotic Leuconostoc mesenteroides strains are unknown. Therefore, this study investigated the potentials of eleven L. mesenteroides strains on the Th1/Th2 balance in vitro by evaluating the expression patterns of interferon-gamma (IFN-γ) (Th1 cytokine) and interleukin-4 (IL-4) (Th2 cytokine) in mesenteric lymph node-derived lymphocytes from ovalbumin (OVA)-sensitized mice. Among strains, WHH1141 incubation caused the highest IFN-γ/IL-4 ratio. Oral administration of WHH1141 (1 × 109  CFU/mL) in the OVA-induced FA mouse model for 40 days improved the weight loss and FA pathological symptoms and normalized the serum immunoglobulin E levels. Meanwhile, the OVA-induced elevated gene expressions of cytokines (IL-4, IL-5, and IL-13) and tight-junction proteins (ZO-1 and Occludin) and levels of cytokines (IL-4, IL-5, and IL-13) and histamine in the jejunum were restored by WHH1141. Furthermore, WHH1141 reversed the reduced gut microbial diversity and short-chain fatty acid (SCFA) levels, specifically increased Bacteroidota abundance, and decreased Firmicutes abundance in OVA-induced mice. Overall, these findings suggest that WHH1141 exerts FA-alleviating effects on OVA-induced mice, which is involved with the inhibition of the jejunal Th2 immune responses and the modulation of gut microbiome composition and SCFA productions. PRACTICAL APPLICATION: Leuconostoc mesenteroides WHH1141 with FA-alleviating potentials may be considered a promising approach in the mitigation of FA symptoms.

Improvements of Age-Related Cognitive Decline in Mice by Lactobacillus helveticus WHH1889, a Novel Strain with Psychobiotic Properties.

A gradual decline in cognitive function occurs with age. Accumulating evidence suggests that certain probiotic strains exert beneficial effects on age-related cognitive decline. Our previous study revealed that Lactobacillus helveticus WHH1889 attenuated symptoms of anxiety and depression in depressed mice via shaping the 5-hydroxytryptamine (5-HT) and 5-hydroxytryptophan (5-HTP) metabolism and gut microbial community, indicating the psychobiotic potential of WHH1889. In the present study, the effects of WHH1889 on age-related cognitive decline were investigated. WHH1889 was orally administrated (1 × 109 CFU/day) for twelve weeks in aged mice, and their cognitive behaviors, neurochemical factors, cognitive-related gene expressions, neuroinflammation, and serum tryptophan pathway-targeted metabolic profiling, as well as gut microbiome composition were assessed. WHH1889 demonstrated improvement of the cognitive behaviors via the novel object recognition test (NORT), the active shuttle avoidance test (ASAT), the Y-maze test, and the passive avoidance test (PAT). The hippocampal neuronal loss; the declined concentrations of BDNF, 5-HT, and 5-HTP; the decreased gene expressions of neurodegeneration biomarkers; and the increased production of hippocampal inflammatory cytokines in aged mice were restored by WHH1889. In addition, WHH1889 increased the 5-HT/5HTP levels and decreased the serum levels of tryptophan-derived metabolites (e.g., kynurenine, xanthurenic acid, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid). Furthermore, WHH1889 was revealed to shape the gut microbiota community by reversing the relative abundances of Bacteroidota and Firmicutes. The present findings suggest that L. helveticus WHH1889 exerted cognitive improving effects on aged mice, which was associated with the modulation of 5-HT and 5-HTP metabolism and gut microbial composition. The supplementation of WHH1889 may therefore be a promising therapeutic agent for age-related cognitive deficits.

MYCT1 attenuates renal fibrosis and tubular injury in diabetic kidney disease.

Tubulointerstitial abnormalities contribute to the progression of diabetic kidney disease (DKD). However, the underlying mechanism of the pathobiology of tubulointerstitial disease is largely unknown. Here, we showed that MYCT1 expression was downregulated in in vitro and in vivo DKD models. Adeno-associated virus (AAV)-Myct1 significantly attenuated renal dysfunction and tubulointerstitial fibrosis in diabetic db/db mice and downregulated Sp1 transcription and TGF-ß1/SMAD3 pathway activation. In human proximal tubular epithelial cells, high glucose-induced high expression of SP1 and TGF-ß1/SMAD3 pathway activation as well as overaccumulation of extracellular matrix (ECM) were abrogated by MYCT1 overexpression. Mechanistically, the binding of VDR to the MYCT1 promoter was predicted and confirmed using dual-luciferase reporter and ChIP analysis. VDR transcriptionally upregulates MYCT1. Our data reveal MYCT1 as a new and potential therapeutic target in treating DKD.

Association between the composite dietary antioxidant index and chronic kidney disease: evidence from NHANES 2011-2018.

Objectives: There is growing evidence that antioxidant-rich diets protect against chronic kidney disease (CKD). However, the relationship between the Composite Dietary Antioxidant Index (CDAI), an important measure of an antioxidant diet, and CKD has received little attention. Therefore, here we investigated the relationship between the CDAI and CKD through a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) 2011-2018 data. Methods: The CDAI was calculated based on the intake of six dietary antioxidants. A survey-based multivariate linear regression analysis was performed to analyze the independent relationship between the CDAI and CKD. Weighted multivariate regression and subgroup analyses were conducted to explore the relationship between the CDAI and CKD. Results: A total of 6874 NHANES participants represented 181.9 million non-institutionalized US residents (mean age, 46.43 ± 0.38 years; 49.87% female; 40.62% non-Hispanic white; 20.24% non-Hispanic black; and 13.94% Mexican American). The weighted linear regression model with full adjustment for confounding variables was -0.0155 (-0.0417, 0.0107) for Q2 (P for trend <0.0001), -0.0052 (-0.0346, 0.0242) for Q3 (P for trend <0.0001), and -0.0305 (-0.0491, -0.0120) for Q4 (P for trend = 0.0094) upon comparison with the lowest quartile of the CDAI. None of the interactions in any subgroup analysis were statistically significant except for individuals with a history of diabetes or the aged population (≥60 years) (P for interaction <0.05). Conclusions: The CDAI was positively associated with a lower prevalence of CKD in adults in the United States. Further large-scale prospective studies are required to analyze the role of the CDAI in CKD.

Oral administration of Bifidobacterium longum WHH2270 ameliorates type 2 diabetes in rats.

Accumulating evidence suggests that specific probiotic strains exert hypoglycemic effects on type 2 diabetes mellitus (T2DM), and probiotic strains within Bifidobacterium exhibit potential beneficial effects on T2DM. In this study, α-glucosidase inhibitory activities of 14 Bifidobacterium strains were assessed in vitro. The hypoglycemic effects of Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity (42.03%) were then investigated in a high-fat diet/streptozotocin-induced T2DM rat model. Oral administration of WHH2270 (4 × 109 CFU/kg/day) for 8 weeks significantly reversed the reduced body weight and ameliorated the levels of fasting blood glucose, serum triglyceride, serum total cholesterol, glucose tolerance, and insulin resistance in T2DM rats. Using 16S rRNA high-throughput sequencing of feces, WHH2270 was revealed to reshape the gut microbiome composition by increasing the abundances of Lactobacillus and Bifidobacterium and decreasing the abundances of UCG_005, Clostridium, and Faecalibacterium in T2DM rats. Besides, the fecal levels of short-chain fatty acids (SCFAs) including acetate, propionate, and butyrate were also elevated after WHH2270 administration. Moreover, the gene expressions of SCFA receptors FFAR2 and FFAR3 in the colon and pancreas of T2DM rats were restored by WHH2270 administration, accompanied by increased levels of serum acetate. In summary, these results provide evidence that WHH2270 has the potential to improve T2DM symptoms by alleviating hyperglycemia, which was associated with changes in the gut microbiome composition and SCFA production. PRACTICAL APPLICATION: Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity may serve as a promising hypoglycemic agent for the treatment of T2DM.

Heme catabolism mediated by heme oxygenase in uninfected interstitial cells enables efficient symbiotic nitrogen fixation in Lotus japonicus nodules.

Legume nodules produce large quantities of heme required for the synthesis of leghemoglobin (Lb) and other hemoproteins. Despite the crucial function of Lb in nitrogen fixation and the toxicity of free heme, the mechanisms of heme homeostasis remain elusive. Biochemical, cellular, and genetic approaches were used to study the role of heme oxygenases (HOs) in heme degradation in the model legume Lotus japonicus. Heme and biliverdin were quantified and localized, HOs were characterized, and knockout LORE1 and CRISPR/Cas9 mutants for LjHO1 were generated and phenotyped. We show that LjHO1, but not the LjHO2 isoform, is responsible for heme catabolism in nodules and identify biliverdin as the in vivo product of the enzyme in senescing green nodules. Spatiotemporal expression analysis revealed that LjHO1 expression and biliverdin production are restricted to the plastids of uninfected interstitial cells. The nodules of ho1 mutants showed decreased nitrogen fixation, and the development of brown, rather than green, nodules during senescence. Increased superoxide production was observed in ho1 nodules, underscoring the importance of LjHO1 in antioxidant defense. We conclude that LjHO1 plays an essential role in degradation of Lb heme, uncovering a novel function of nodule plastids and uninfected interstitial cells in nitrogen fixation.

Engineering of cyclodextrin glycosyltransferase improves the conversion efficiency of rebaudioside A to glucosylated steviol glycosides and increases the content of short-chain glycosylated steviol glycoside.

BACKGROUND: Compared with steviol glycosides, the taste of glucosylated steviol glycosides is better and more similar to that of sucrose. At present, cyclodextrin glucanotransferase (CGTase) is primarily used to catalyze the conversion of steviol glycosides to glucosylated steviol glycosides, with soluble starch serving as a glycosyl donor. The main disadvantages of enzymatic transglycosylation are the limited number of enzymes available, the low conversion rates that result in low yields, and the lack of selectivity in the degree of glycosylation of the products. In order to fill these gaps, the proteome of Alkalihalobacillus oshimensis (also named Bacillus oshimensis) was used for mining novel CGTases. RESULTS: Here, CGTase-15, a novel ß-CGTase with a wide pH adaptation range, was identified and characterized. The catalyzed product of CGTase-15 tasted better than that of the commercial enzyme (Toruzyme® 3.0 L). In addition, two amino acid sites, Y199 and G265, which play important roles in the conversion of steviol glycosides to glucosylated steviol glycosides were identified by site-directed mutagenesis. Compared with CGTase-15, CGTase-15-Y199F mutant significantly increased the conversion rate of rebaudioside A (RA) to glucosylated steviol glycosides. Compared with CGTase-15, the content of short-chain glycosylated steviol glycosides catalyzed by CGTase-15-G265A mutant was significantly increased. Moreover, the function of Y199 and G265 was verified in other CGTases. The above mutation pattern has also been applied to CGTase-13 (a CGTase discovered by our laboratory with great potential in the production of glycosylated steviol glycosides), confirming that the catalytic product of CGTase-13-Y189F/G255A mutant has a better taste than that of CGTase-13. CONCLUSIONS: This is the first report on the improvement of the sensory profiles of glycosylated steviol glycosides through site-directed mutagenesis of CGTase, which is significant for the production of glycosylated steviol glycosides.

YY1-induced upregulation of LncRNA-ARAP1-AS2 and ARAP1 promotes diabetic kidney fibrosis via aberrant glycolysis associated with EGFR/PKM2/HIF-1α pathway.

Objectives: Dimeric pyruvate kinase (PK) M2 (PKM2) plays an important role in promoting the accumulation of hypoxia-inducible factor (HIF)-1α, mediating aberrant glycolysis and inducing fibrosis in diabetic kidney disease (DKD). The aim of this work was to dissect a novel regulatory mechanism of Yin and Yang 1 (YY1) on lncRNA-ARAP1-AS2/ARAP1 to regulate EGFR/PKM2/HIF-1α pathway and glycolysis in DKD. Materials and methods: We used adeno-associated virus (AAV)-ARAP1 shRNA to knocked down ARAP1 in diabetic mice and overexpressed or knocked down YY1, ARAP1-AS2 and ARAP1 expression in human glomerular mesangial cells. Gene levels were assessed by Western blotting, RT-qPCR, immunofluorescence staining and immunohistochemistry. Molecular interactions were determined by RNA pull-down, co-immunoprecipitation, ubiquitination assay and dual-luciferase reporter analysis. Results: YY1, ARAP1-AS2, ARAP1, HIF-1α, glycolysis and fibrosis genes expressions were upregulated and ARAP1 knockdown could inhibit dimeric PKM2 expression and partly restore tetrameric PKM2 formation, while downregulate HIF-1α accumulation and aberrant glycolysis and fibrosis in in-vivo and in-vitro DKD models. ARAP1 knockdown attenuates renal injury and renal dysfunction in diabetic mice. ARAP1 maintains EGFR overactivation in-vivo and in-vitro DKD models. Mechanistically, YY1 transcriptionally upregulates ARAP1-AS2 and indirectly regulates ARAP1 and subsequently promotes EGFR activation, HIF-1α accumulation and aberrant glycolysis and fibrosis. Conclusion: Our results first highlight the role of the novel regulatory mechanism of YY1 on ARAP1-AS2 and ARAP1 in promoting aberrant glycolysis and fibrosis by EGFR/PKM2/HIF-1α pathway in DKD and provide potential therapeutic strategies for DKD treatments.

A transcription factor of the NAC family regulates nitrate-induced legume nodule senescence.

Legumes establish symbioses with rhizobia by forming nitrogen-fixing nodules. Nitrate is a major environmental factor that affects symbiotic functioning. However, the molecular mechanism of nitrate-induced nodule senescence is poorly understood. Comparative transcriptomic analysis reveals an NAC-type transcription factor in Lotus japonicus, LjNAC094, that acts as a positive regulator in nitrate-induced nodule senescence. Stable overexpression and mutant lines of NAC094 were constructed and used for phenotypic characterization. DNA-affinity purification sequencing was performed to identify NAC094 targeting genes and results were confirmed by electrophoretic mobility shift and transactivation assays. Overexpression of NAC094 induces premature nodule senescence. Knocking out NAC094 partially relieves nitrate-induced degradation of leghemoglobins and abolishes nodule expression of senescence-associated genes (SAGs) that contain a conserved binding motif for NAC094. Nitrate-triggered metabolic changes in wild-type nodules are largely affected in nac094 mutant nodules. Induction of NAC094 and its targeting SAGs was almost blocked in the nitrate-insensitive nlp1, nlp4, and nlp1 nlp4 mutants. We conclude that NAC094 functions downstream of NLP1 and NLP4 by regulating nitrate-induced expression of SAGs. Our study fills in a key gap between nitrate and the execution of nodule senescence, and provides a potential strategy to improve nitrogen fixation and stress tolerance of legumes.

The supplementation of the multi-strain probiotics WHHPRO™ alleviates high-fat diet-induced metabolic symptoms in rats via gut-liver axis.

Metabolic syndrome (MS) has emerged as one of the major global health concerns, accompanied by a series of related complications, such as obesity and type-2 diabetes. The gut-liver axis (GLA) is a bidirectional communication between the gut and the liver. The GLA alterations have been revealed to be closely associated with the development of MS. Probiotics within Lactobacillus and Bifidobacterium confer beneficial effects on improving MS symptoms. WHHPRO™ is a mixture of four probiotic strains, with potential MS-improving abilities. This study aimed to investigate the effects of WHHPRO™ on MS symptoms using a high-fat diet (HFD) rat model. Oral administration of WHHPRO™ for 12 weeks improved glucose tolerance, blood lipid, body weight, and liver index in HFD rats. WHHPRO™ shaped the gut microbiome composition by increasing the abundance of Lactobacillus and Akkermansia and normalized the reduced SCFA levels in HFD rats. Besides, WHHPRO™ modulated the fecal bile acids (BAs) profile, with decreased levels of T-b-MCA and 12-KDCA and increased levels of LCA and ILCA. Meanwhile, WHHPRO™ increased total unconjugated BAs in feces and liver and reduced the accumulation of total hepatic BA pool size in HFD rats. Moreover, WHHPRO™ reversed the expression of genes associated with impaired BA metabolism signaling in the ileum and liver. Our findings suggest that WHHPRO™ exerted beneficial effects on improving MS symptoms, involving the modulation of the gut microbiome composition, SCFAs, and the FXR-FGF15 signaling along the GLA. Supplementation of WHHPRO™ may serve as a novel strategy for improving MS symptoms.

Genetically predicted body fat mass and distribution with diabetic kidney disease: A two-sample Mendelian randomization study.

The aim of this study is to apply a Mendelian randomization (MR) design to investigate the potential causal associations between the body mass index (BMI), body fat mass such as trunk fat mass and waist circumference (WC), and diabetic kidney disease (DKD). A two-sample MR study was conducted to obtain exposure and outcome data from previously published studies. The instrumental variables for BMI, trunk fat mass, and WC were selected from genome-wide association study datasets based on summary-level statistics. The random-effects inverse-variance weighted (IVW) method was used for the main analyses, and the weighted median and MR-Egger approaches were complementary. In total, three MR methods suggested that genetically predicted BMI, trunk fat mass, and WC were positively associated with DKD. Using IVW, we found evidence of causal relationships between BMI [odds ratio (OR) = 1.99; 95% confidence interval (CI), 1.47-2.69; p = 7.89 × 10-6], trunk fat mass (OR = 1.80; 95% CI, 1.28-2.53; p = 6.84 × 10-4), WC (OR = 2.48; 95% CI, 1.40-4.42; p = 1.93 × 10-3), and DKD. MR-Egger and weighted median regression also showed directionally similar estimates. Both funnel plots and MR-Egger intercepts showed no directional pleiotropic effects involving the aforementioned variables and DKD. Our MR analysis supported the causal effect of BMI, trunk fat mass, and WC on DKD. Individuals can substantially reduce DKD risk by reducing body fat mass and modifying their body fat distribution.

A Wild Rice Rhizobacterium Burkholderiacepacia BRDJ Enhances Nitrogen Use Efficiency in Rice.

Rice domestication has dramatically improved its agronomic traits, albeit with unavoidable significantly reduced genetic diversity. Dongxiang common wild rice, the wild rice species distributed in northernmost China, exhibits excellent resistance against stress and diseases and provides a rich genetic resource for rice breeding. Most of the studies focus on the function of the plant genes, often disregarding the role of the root microbes associated with the plants. In this work, we isolated a Burkholderia strain from the root of Dongxiang wild rice, which we identified as Burkholderia cepacia BRDJ, based on a phylogenetic analysis. This strain promoted the rice growth under greenhouse conditions. The grain yield was higher in a rice line containing a small genomic fragment derived from the Dongxiang wild rice, compared to the indica rice cultivar Zhongzao 35. This new strain also increased the plant biomass under limiting nitrogen conditions. Interestingly, this strain had a differential effect on indica and japonica rice varieties under full nitrogen supply conditions. By genome sequencing and comparison with another two B. cepacia strains, we observed enriched genes related with nitrogen fixation and phytohormone and volatiles biosynthesis that may account for the growth-promoting effects of the BRDJ. BRDJ has the potential to be used as a biofertilizer in promoting nitrogen use efficiency and overall growth in rice.

Heme oxygenase-independent bilin biosynthesis revealed by a hmox1 suppressor screening in Chlamydomonas reinhardtii.

Bilins are open-chain tetrapyrroles synthesized in phototrophs by successive enzymic reactions catalyzed by heme oxygenases (HMOXs/HOs) and ferredoxin-dependent biliverdin reductases (FDBRs) that typically serve as chromophore cofactors for phytochromes and phycobiliproteins. Chlamydomonas reinhardtii lacks both phycobiliproteins and phytochromes. Nonetheless, the activity and stability of photosystem I (PSI) and the catalytic subunit of magnesium chelatase (MgCh) named CHLH1 are significantly reduced and phototropic growth is significantly attenuated in a hmox1 mutant that is deficient in bilin biosynthesis. Consistent with these findings, previous studies on hmox1 uncovered an essential role for bilins in chloroplast retrograde signaling, maintenance of a functional photosynthetic apparatus, and the direct regulation of chlorophyll biosynthesis. In this study, we generated and screened a collection of insertional mutants in a hmox1 genetic background for suppressor mutants with phototropic growth restored to rates observed in wild-type 4A+ C. reinhardtii cells. Here, we characterized a suppressor of hmox1 named ho1su1 with phototrophic growth rates and levels of CHLH1 and PSI proteins similar to 4A+. Tetrad analysis indicated that a plasmid insertion co-segregated with the suppressor phenotype of ho1su1. Results from TAIL-PCR and plasmid rescue experiments demonstrated that the plasmid insertion was located in exon 1 of the HMOX1 locus. Heterologous expression of the bilin-binding reporter Nostoc punctiforme NpF2164g5 in the chloroplast of ho1su1 indicated that bilin accumulated in the chloroplast of ho1su1 despite the absence of the HMOX1 protein. Collectively, our study reveals the presence of an alternative bilin biosynthetic pathway independent of HMOX1 in the chloroplasts of Chlamydomonas cells.

[Exploration and practice of synthetic biology teaching mode based on research frontiers and hotspots].

Synthetic biology, a course with a sound theoretical system and a wide application range, plays a role in the cultivation of innovative talents in the field of bioengineering. To this end, we have set up a synthetic biology course in our university. First, according to the concept of imparting basic knowledge, highlighting innovative practice, and keeping up with cutting-edge progress, we assembled a high-level teaching team for synthetic biology. The team constantly adjusted and optimized the course contents and achieved a novel and reasonable course system. Second, we introduced frontier cases of synthetic biology reported in high-level journals, as well as breaking news in this field in classroom teaching, which enriched the teaching contents and aroused students' interest. Third, taking these cases as the breakthrough point, we guided students to in-depth discussions through the learning-centered teaching mode to improve students' abilities of critical thinking and theoretical innovation. In summary, the course has achieved good teaching outcomes and improved the cultivation of innovative talents. Therefore, we share our work with peer teachers, aiming to give new insights into the teaching reform of synthetic biology and other related courses.

Excessive Activation of Notch Signaling in Macrophages Promote Kidney Inflammation, Fibrosis, and Necroptosis.

Diabetic nephropathy (DN) is one of the main causes of end-stage renal disease (ESRD). Existing treatments cannot control the progression of diabetic nephropathy very well. In diabetic nephropathy, Many monocytes and macrophages infiltrate kidney tissue. However, the role of these cells in the pathogenesis of diabetic nephropathy has not been fully elucidated. In this study, we analyzed patient kidney biopsy specimens, diabetic nephropathy model animals. Meanwhile, we cocultured cells and found that in diabetic nephropathy, damaged intrinsic renal cells (glomerular mesangial cells and renal tubular epithelial cells) recruited monocytes/macrophages to the area of tissue damage to defend against and clear cell damage. This process often involved the activation of different types of macrophages. Interestingly, the infiltrating macrophages were mainly M1 (CD68+iNOS+) macrophages. In diabetic nephropathy, crosstalk between the Notch pathway and NF-κB signaling in macrophages contributed to the polarization of macrophages. Hyperpolarized macrophages secreted large amounts of inflammatory cytokines and exacerbated the inflammatory response, extracellular matrix secretion, fibrosis, and necroptosis of intrinsic kidney cells. Additionally, macrophage depletion therapy with clodronate liposomes and inhibition of the Notch pathway in macrophages alleviated the pathological changes in kidney cells. This study provides new information regarding diabetic nephropathy-related renal inflammation, the causes of macrophage polarization, and therapeutic targets for diabetic nephropathy.