Indole-3-carbinol ameliorates ovarian damage in female old mice through Nrf2/HO-1 pathway activation.

Ovarian aging leads to infertility and birth defects. We aimed to clarify the role of Indole-3-carbinol (I3C) in resistance to oxidative stress, apoptosis, and fibrosis in ovarian aging. I3C was administered via intraperitoneal injection for 3 weeks in young or old mice. Immunohistochemistry; Masson, Sirius red, and TUNEL staining; follicle counting; estrous cycle analysis; and Western blotting were used for validating the protective effect of I3C against ovarian senescence. Human granulosa-like tumor cell line and primary granulosa cells were used for in vitro assay. The results indicated that I3C inhibited ovarian fibrosis and apoptosis while increasing the number of primordial follicles. Mechanistic studies have shown that I3C promoted the nuclear translocation of nuclear factor-erythroid 2-related factor (Nrf2) and upregulated the expression of heme oxygenase 1 (HO-1). Additionally, I3C increased cell viability and decreased lactate dehydrogenase, malondialdehyde, reactive oxygen species and JC-1 levels. Furthermore, the antioxidant effect of I3C was found to be dependent on the activation of Nrf2 and HO-1, as demonstrated by the disappearance of the effect upon inhibition of Nrf2 expression. In conclusion, I3C can alleviate the ovarian damage caused by aging and may be a protective agent to delay ovarian aging.

Inhibition of cisplatin-induced Acsl4-mediated ferroptosis alleviated ovarian injury.

Given that the severity of the chemotherapy-induced ovarian damage, effective fertility preservation is a necessary part of the treatment process. Ferroptosis is a regulated cell death triggered by excessive phospholipid peroxidation caused by iron and the role of ferroptosis in chemotherapy-induced ovarian damage remains unclear. In this study, we demonstrated that cisplatin treatment caused the accumulation of iron ions which induced ferroptosis in ovarian tissue. And our results show that ferrostatin-1 was able to suppress the ovarian injury and granulosa cell death caused by cisplatin (Cis) in vivo and in vitro. At the same time, we observed significant changes in the expression levels of Acyl-CoA synthetase long-chain family member 4 (Acsl4) and glutathione peroxidase 4 (GPX4). Similarly, Rosiglitazone, an inhibitor of Acsl4, administration alleviated the ovary damage of the mice undergoing chemotherapy. Further mechanistic investigation showed that cisplatin increased the expression level of specificity protein 1 (SP1), and SP1 could bind to the promoter of Acsl4 to increased Acsl4 transcription. Overall, ferroptosis plays an important role in Cis induced ovarian injury, and inhibition of ferroptosis protects ovarian tissues from damage caused by cisplatin, and for the first time, we have identified the potential of Fer-1 and Rosi to protect ovarian function in female mice undergoing chemotherapy.

Didymin alleviates metabolic dysfunction-associated fatty liver disease (MAFLD) via the stimulation of Sirt1-mediated lipophagy and mitochondrial biogenesis.

BACKGROUND: Metabolic dysfunction-associated fatty liver disease (MAFLD) is one of the most prevalent metabolic syndromes worldwide. However, no approved pharmacological treatments are available for MAFLD. Chenpi, one kind of dried peel of citrus fruits, has traditionally been utilized as a medicinal herb for liver diseases. Didymin is a newly identified oral bioactive dietary flavonoid glycoside derived from Chenpi. In this study, we investigated the therapeutic potential of Didymin as an anti-MAFLD drug and elucidated its underlying mechanisms. METHODS: High-fat diet (HFD)-induced MAFLD mice and alpha mouse liver 12 (AML12) cells were utilized to evaluate the effects and mechanisms of Didymin in the treatment of MAFLD. Liver weight, serum biochemical parameters, and liver morphology were examined to demonstrate the therapeutic efficacy of Didymin in MAFLD treatment. RNA-seq analysis was performed to identify potential pathways that could be affected by Didymin. The impact of Didymin on Sirt1 was corroborated through western blot, molecular docking analysis, microscale thermophoresis (MST), and deacetylase activity assay. Then, a Sirt1 inhibitor (EX-527) was utilized to confirm that Didymin alleviates MAFLD via Sirt1. Western blot and additional assays were used to investigate the underlying mechanisms. RESULTS: Our results suggested that Didymin may possess therapeutic potential against MAFLD in vitro and in vivo. By promoting Sirt1 expression as well as directly binding to and activating Sirt1, Didymin triggers downstream pathways that enhance mitochondrial biogenesis and function while reducing apoptosis and enhancing lipophagy. CONCLUSIONS: These suggest that Didymin could be a promising medication for MAFLD treatment. Furthermore, its therapeutic effects are mediated by Sirt1.

Puerarin ameliorates metabolic dysfunction-associated fatty liver disease by inhibiting ferroptosis and inflammation.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is frequently linked to type 2 diabetes mellitus (T2DM), and both conditions exacerbate the progression of the other. However, there is currently no standardized treatment or drug for MAFLD. In this study, A MAFLD animal model through a high-fat diet (HFD) along with administration of streptozotocin (STZ), and palmitic acid (PA)-induced AML12 cells were treated by puerarin. The objective of this study was to assess the therapeutic effect of puerarin, a flavonoid substance that possesses various pharmacological properties, on MAFLD. The results showed that puerarin administration enhanced glucose tolerance and insulin sensitivity, while also mitigating liver dysfunction and hyperlipidemia in MAFLD mice. Moreover, puerarin attenuated oxidative stress levels and inflammation in the liver. Transmission electron microscopy and Western blot analysis indicated that puerarin inhibited ferroptosis in vivo. Further mechanistic investigations revealed that puerarin upregulated SIRT1 expression, increased nuclear factor erythroid 2-related factor 2 (Nrf2) protein levels, and facilitated translocation into the nucleus. The protective effect of puerarin on PA-induced AML12 cells was diminished by the utilization of EX-527 (a SIRT1 inhibitor) and Nrf2 siRNA. Overall, the results demonstrate that puerarin ameliorates MAFLD by suppressing ferroptosis and inflammation via the SIRT1/Nrf2 signaling pathway. The results emphasize the possible medicinal application of puerarin for managing MAFLD.

The relationship between cadmium exposure and hepatitis B susceptibility and the establishment of its prediction model.

Cadmium, a common metal, is an environmental contaminant that is hepatotoxic and immunotoxic. Cadmium exposure may affect hepatitis B immunity. The purpose of this study was to assess the association between cadmium exposure and hepatitis B serology in the US population and to develop a model to predict susceptibility of hepatitis B. The study included 50,588 individuals in the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2016. Univariate and multivariate logistic regression and dose-response curves were used to evaluate the relationship between cadmium exposure and hepatitis B serology. Through multivariate logistic regression results, a predictive model was established, and relevant indicators were used to verify the clinical value of the model and evaluate prognostic value of serum cadmium concentration in patients with hepatitis B. We selected 5989 (≥ 6 years old) participants. Univariate logistic regression analysis showed that gender (aOR = 0.7192, 95% CI = 0.6492-0.7968), age (aOR = 1.030, 95% CI = 1.026-1.033), race (aOR = 0.8974, 95% CI = 0.8591-0.9374), poverty ratio (aOR = 1.042, 95% CI = 0.9872-1.101), body mass index (BMI) (aOR = 1.052, 95% CI = 1.044-1.061), hypertension (aOR = 2.017, 95% CI = 1.763-2.306), diabetes (aOR = 2.673, 95% CI = 2.119-3.370), vigorous recreational activities (aOR = 0.6369, 95% CI = 0.5725-0.7085), moderate recreational activity (aOR = 0.7681, 95% CI = 0.6935-0.8574) and cadmium (aOR = 1.295, 95% CI = 1.168-1.436) were closely related to hepatitis B virus (HBV) susceptibility. After adjusting for these confounding factors, multivariate logistic regression analysis showed that the odds ratio of HBV susceptibility was positively correlated with the level of cadmium in serum. The effectiveness of the model was then evaluated by establishing a nomogram, and by calibration curves, ROC curves, and clinical decision curves. Our study shows that cadmium exposure is positively associated with HBV susceptibility risk in the US population, and the constructed model has clinical significance.

Mesenchymal stromal cells ameliorate diabetes-induced muscle atrophy through exosomes by enhancing AMPK/ULK1-mediated autophagy.

BACKGROUND: Diabetes and obesity are associated with muscle atrophy that reduces life quality and lacks effective treatment. Mesenchymal stromal cell (MSC)-based therapy can ameliorate high fat-diet (HFD) and immobilization (IM)-induced muscle atrophy in mice. However, the effect of MSCs on muscle atrophy in type 2 diabetes mellitus (T2DM) and the potential mechanism is unclear. Here, we evaluated the efficacy and explored molecular mechanisms of human umbilical cord MSCs (hucMSCs) and hucMSC-derived exosomes (MSC-EXO) on diabetes- and obesity-induced muscle atrophy. METHODS: Diabetic db/db mice, mice fed with high-fat diet (HFD), mice with hindlimb immobilization (IM), and C2C12 myotubes were used to explore the effect of hucMSCs or MSC-EXO in alleviating muscle atrophy. Grip strength test and treadmill running were used to measure skeletal muscle strength and performance. Body composition, muscle weight, and muscle fibre cross-sectional area (CSA) was used to evaluate muscle mass. RNA-seq analysis of tibialis anterior (TA) muscle and Western blot analysis of muscle atrophy signalling, including MuRF1 and Atrogin 1, were performed to investigate the underlying mechanisms. RESULTS: hucMSCs increased grip strength (P = 0.0256 in db/db mice, P = 0.012 in HFD mice, P = 0.0097 in IM mice), running endurance (P = 0.0154 in HFD mice, P = 0.0006 in IM mice), and muscle mass (P = 0.0004 in db/db mice, P = 0.0076 in HFD mice, P = 0.0144 in IM mice) in all models tested, with elevated CSA of muscle fibres (P < 0.0001 in db/db mice and HFD mice, P = 0.0088 in IM mice) and reduced Atrogin1 (P = 0.0459 in db/db mice, P = 0.0088 in HFD mice, P = 0.0016 in IM mice) and MuRF1 expression (P = 0.0004 in db/db mice, P = 0.0077 in HFD mice, P = 0.0451 in IM mice). MSC-EXO replicated all these hucMSC-mediated changes (P = 0.0103 for grip strength, P = 0.013 for muscle mass, P < 0.0001 for CSA of muscle fibres, P = 0.0171 for Atrogin1 expression, and P = 0.006 for MuRF1 expression). RNA-seq revealed that hucMSCs activated the AMPK/ULK1 signalling and enhanced autophagy. Knockdown of AMPK or inhibition of autophagy with 3-methyladenine (3-MA) diminished the beneficial anti-atrophy effects of hucMSCs or MSC-EXO. CONCLUSIONS: Our results suggest that human umbilical cord mesenchymal stromal cells mitigate diabetes- and obesity-induced muscle atrophy via enhancing AMPK/ULK1-mediated autophagy through exosomes, with implications of applying hucMSCs or hucMSC-derived exosomes to treat muscle atrophy.

The relationship between ethylene oxide levels in hemoglobin and the prevalence of kidney stones in US adults: an exposure-response analysis from NHANES 2013-2016.

Exposure to ethylene oxide may cause a number of diseases. The purpose of this study was to investigate whether there is an association between hemoglobin ethylene oxide (HbEO) and the risk of developing kidney stones in US adults. We analyzed 3348 patients from the National Health and Nutrition Survey (NHANES) 2013-2016 and conducted a cross-sectional study. Dose-response analysis curves of restricted cubic spline function, multiple logistic regression, and subgroup analysis were used to investigate the association between HbEO and the risk of kidney stones. Logistic regression models were used to analyze the correlation between HbEO and kidney stones. Among the 3348 participants, 3016 people self-reported having a kidney stone. After adjusting for age, sex, race, marital status, education level, diabetes, vigorous recreational activity, moderate recreational activity, body mass index, blood urea nitrogen, creatinine, eGFR, and uric acid, we found a positive association between HbEO and the risk of kidney stones. We divided patients into four groups based on quartiles of HbEO levels and performed multifactorial logistic regression after adjusting for confounders, which showed that the incidence of kidney stones increased with increasing HbEO concentrations compared with Q1 (Q2, OR = 0.922, 95% CI, 0. 657-1.295, P = 0.639; Q3, OR = 1.004, 95% CI, 0.713-1.414, P = 0.983; Q4, OR = 1.535, 95% CI, 1.114-2.114, P = 0.009). High levels of HbEO were positively correlated with the risk of kidney stone development and could be used as an indicator of kidney stone prevention.

Exosomes derived from mesenchymal stem cells attenuate diabetic kidney disease by inhibiting cell apoptosis and epithelial-to-mesenchymal transition via miR-424-5p.

Diabetic kidney disease (DKD) is well-acknowledged as one of the most common complications in diabetes mellitus. Recent studies have demonstrated the promising role of mesenchymal stem cell-derived exosomes (MSC-exos) as a cell-free treatment strategy for DKD. The present study sought to investigate the therapeutic potential and the underlying mechanisms of MSC-exos in DKD. The authentication of MSC-exos was validated by western blot, transmission electron microscope (TEM), and nanosight tracking analysis (NTA). Apoptosis was detected by western blot, TUNEL staining, and flow cytometry. Epithelial-to-mesenchymal transition (EMT) was evaluated by western blot and immunofluorescence. The relationship between miR-424-5p and Yes-associated protein 1 (YAP1) was revealed by dual luciferase reporter assay. We observed that MSC-exos could attenuate DKD by decreasing cell apoptosis and inhibiting epithelial-to-mesenchymal transition (EMT) in diabetic kidneys in db/db mice. Besides, we documented that MSC-exos could reverse high glucose-induced apoptosis and EMT in HK2 cells. Interestingly, miR-424-5p derived from MSC-exos could inhibit YAP1 activation in HK2 cells, resulting in alleviation of high glucose-induced cell apoptosis and EMT. Our study provides novel insights into MSC-exos-mediated protective effect in DKD. MSC-exos could inhibit high glucose-induced apoptosis and EMT through miR-424-5p targeting of YAP1.

Mesenchymal stem cell-derived exosomal miR-146a reverses diabetic ß-cell dedifferentiation.

BACKGROUND: Mesenchymal stem cells (MSCs) show promising therapeutic potential in treating type 2 diabetes mellitus (T2DM) in clinical studies. Accumulating evidence has suggested that the therapeutic effects of MSCs are not due to their direct differentiation into functional ß-cells but are instead mediated by their paracrine functions. Among them, exosomes, nano-sized extracellular vesicles, are important substances that exert paracrine functions. However, the underlying mechanisms of exosomes in ameliorating T2DM remain largely unknown. METHODS: Bone marrow mesenchymal stem cell (bmMSC)-derived exosomes (bmMDEs) were administrated to T2DM rats and high-glucose-treated primary islets in order to detect their effects on ß-cell dedifferentiation. Differential miRNAs were then screened via miRNA sequencing, and miR-146a was isolated after functional verification. TargetScan, reporter gene detection, insulin secretion assays, and qPCR validation were used to predict downstream target genes and involved signaling pathways of miR-146a. RESULTS: Our results showed that bmMDEs reversed diabetic ß-cell dedifferentiation and improved ß-cell insulin secretion both in vitro and in vivo. Results of miRNA sequencing in bmMDEs and subsequent functional screening demonstrated that miR-146a, a highly conserved miRNA, improved ß-cell function. We further found that miR-146a directly targeted Numb, a membrane-bound protein involved in cell fate determination, leading to activation of ß-catenin signaling in ß-cells. Exosomes derived from miR-146a-knockdown bmMSCs lost the ability to improve ß-cell function. CONCLUSIONS: These findings demonstrate that bmMSC-derived exosomal miR-146a protects against diabetic ß-cell dysfunction by acting on the NUMB/ß-catenin signaling pathway, which may represent a novel therapeutic strategy for T2DM.

Mesenchymal stem cell-conditioned medium alleviates high fat-induced hyperglucagonemia via miR-181a-5p and its target PTEN/AKT signaling.

BACKGROUND: α-cell dysregulation gives rise to fasting and postprandial hyperglycemia in type 2 diabetes mellitus(T2DM). Administration of Mesenchymal stem cells (MSCs) or their conditioned medium can improve islet function and enhance insulin secretion. However, studies showing the direct effect of MSCs on islet α-cell dysfunction are limited. METHODS: In this study, we used high-fat diet (HFD)-induced mice and α-cell line exposure to palmitate (PA) to determine the effects of bone marrow-derived MSC-conditioned medium (bmMSC-CM) on glucagon secretion. Plasma and supernatant glucagon were detected by enzyme-linked immunosorbent assay(ELISA). To investigate the potential signaling pathways, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), AKT and phosphorylated AKT(p-AKT) were assessed by Western blotting. RESULTS: In vivo, bmMSC-CM infusion improved the glucose and insulin tolerance and protected against HFD-induced hyperglycemia and hyperglucagonemia. Meanwhile, bmMSC-CM infusion ameliorated HFD-induced islet hypertrophy and decreased α- and ß-cell area. Consistently, in vitro, glucagon secretion from α-cells or primary islets was inhibited by bmMSC-CM, accompanied by reduction of intracellular PTEN expression and restoration of AKT signaling. Previous studies and the TargetScan database indicate that miR-181a and its target PTEN play vital roles in ameliorating α-cell dysfunction. We observed that miR-181a-5p was highly expressed in BM-MSCs but prominently lower in αTC1-6 cells. Overexpression or downregulation of miR-181a-5p respectively alleviated or aggravated glucagon secretion in αTC1-6 cells via the PTEN/AKT signaling pathway. CONCLUSIONS: Our observations suggest that MSC-derived miR-181a-5p mitigates glucagon secretion of α-cells by regulating PTEN/AKT signaling, which provides novel evidence demonstrating the potential for MSCs in treating T2DM.

Melatonin prevents diabetes-associated cognitive dysfunction from microglia-mediated neuroinflammation by activating autophagy via TLR4/Akt/mTOR pathway.

Cognitive dysfunction often occurs in diabetes mellitus patients. This study aimed to investigate the efficacy of melatonin (MLT) in improving diabetes-associated cognitive decline and the underlying mechanism involved. Type 2 diabetic mice and palmitic acid (PA)-stimulated BV-2 cells were treated by MLT, and the potential mechanisms among MLT, cognition, and autophagy were explored. The results showed that type 2 diabetic mice showed obvious learning and memory impairments in the Morris water maze test compared with normal controls, which could be ameliorated by MLT treatment. Meanwhile, MLT administration significantly improved neuroinflammation and regulated microglial apoptosis. Furthermore, autophagy inhibitor 3-methyladenine (3-MA) increased the microglial inflammation and apoptosis, indicating that the treatment effect of MLT was mediated by autophagy. Lastly, MLT treatment significantly decreased the levels of toll-like receptors 4 (TLR4), phosphorylated-protein kinase B (Akt), and phosphorylated-mechanistic target of rapamycin (mTOR), indicating that blocking TLR4/Akt/mTOR pathway might be an underlying basis for the anti-inflammatory and anti-apoptosis effects of MLT. Collectively, our study suggested that MLT could improve learning and memory in type 2 diabetic mice by activating autophagy via the TLR4/Akt/mTOR pathway, thereby inhibiting neuroinflammation and microglial apoptosis.

Mesenchymal stem cell-conditioned medium improved mitochondrial function and alleviated inflammation and apoptosis in non-alcoholic fatty liver disease by regulating SIRT1.

Non-alcoholic fatty liver disease (NAFLD), an emerging risk factor for diabetes, is now recognized as the most common liver disease worldwide. Mesenchymal stem cells (MSCs), a promising tool in regenerative medicine, release abundant molecules into the conditioned medium (CM). Increasing evidence showed that MSC-CM is beneficial for diabetes-associated NAFLD. However, the mechanism of how MSC-CM improves NAFLD remains uncertain. In this study, to determine the effects of MSC-CM on NAFLD, streptozotocin (STZ) and high-fat diet (HFD) induced T2DM mice model and palmitic acid (PA)-stimulated L-O2 cells were used and treated with MSC-CM. Our results demonstrated that MSC-CM improved insulin resistance in diabetic mice, amended the pathological structure of the liver, enhanced the liver's total antioxidant capacity and mitochondrial function, reduced inflammation and cell apoptosis. We further verified that SIRT1 played a key role in mediating the protective effect of MSC-CM. These findings provide novel evidence that MSC-CM has the potential to treat T2DM patients with NAFLD clinically.

Mesenchymal stem cell-derived exosomes exert ameliorative effects in type 2 diabetes by improving hepatic glucose and lipid metabolism via enhancing autophagy.

BACKGROUND: Mesenchymal stem cell (MSC)-based therapy is currently considered to be an effective treatment strategy for diabetes and hepatic disorders, such as liver cirrhosis and non-alcoholic fatty liver disease. Exosomes are important mediators of cellular connections, and increasing evidence has suggested that exosomes derived from MSCs may be used as direct therapeutic agents; their mechanisms of action, however, remain largely unclear. Here, we evaluated the efficacy and molecular mechanisms of human umbilical cord MSC-derived exosomes (HucMDEs) on hepatic glucose and lipid metabolism in type 2 diabetes mellitus (T2DM). METHODS: HucMDEs were used to treat T2DM rats, as well as palmitic acid (PA)-treated L-O2 cells, in order to determine the effects of HucMDEs on hepatic glucose and lipid metabolism. To evaluate the changes in autophagy and potential signaling pathways, autophagy-related proteins (BECN1, microtubule-associated protein 1 light chain 3 beta [MAP 1LC3B]), autophagy-related genes (ATGs, ATG5, and ATG7), AMP-activated protein kinase (AMPK), and phosphorylated AMPK (p-AMPK) were assessed by Western blotting. RESULTS: HucMDEs promoted hepatic glycolysis, glycogen storage, and lipolysis, and reduced gluconeogenesis. Additionally, autophagy potentially contributed to the effects of HucMDE treatment. Transmission electron microscopy revealed an increased formation of autophagosomes in HucMDE-treated groups, and the autophagy marker proteins, BECN1 and MAP 1LC3B, were also increased. Moreover, autophagy inhibitor 3-methyladenine significantly reduced the effects of HucMDEs on glucose and lipid metabolism in T2DM rats. Based on its phosphorylation status, we found that the AMPK signaling pathway was activated and induced autophagy in T2DM rats and PA-treated L-O2 cells. Meanwhile, the transfection of AMPK siRNA or application of the AMPK inhibitor, Comp C, weakened the therapeutic effects of HucMDEs on glucose and lipid metabolism. CONCLUSIONS: These findings demonstrate that HucMDEs improved hepatic glucose and lipid metabolism in T2DM rats by activating autophagy via the AMPK pathway, which provides novel evidence suggesting the potential for HucMDEs in clinically treating T2DM patients.

Enterotype Bacteroides Is Associated with a High Risk in Patients with Diabetes: A Pilot Study.

BACKGROUND: More and more studies focus on the relationship between the gastrointestinal microbiome and type 2 diabetes, but few of them have actually explored the relationship between enterotypes and type 2 diabetes. Materials and Methods. We enrolled 134 patients with type 2 diabetes and 37 nondiabetic controls. The anthropometric and clinical indices of each subject were measured. Fecal samples of each subject were also collected and were processed for 16S rDNA sequencing. Multiple logistic regression analysis was used to determine the associations of enterotypes with type 2 diabetes. Multiple linear regression analysis was used to explore the relationship between lipopolysaccharide levels and insulin sensitivity after adjusting for age, BMI, TG, HDL-C, DAO, and TNF-α. The correlation analysis between factors and microbiota was identified using Spearman correlation analysis. The correlation analysis between factors was identified using partial correlation analysis. RESULTS: Gut microbiota in type 2 diabetes group exhibited lower bacterial diversity compared with nondiabetic controls. The fecal communities from all subjects clustered into two enterotypes distinguished by the levels of Bacteroides and Prevotella. Logistic regression analysis showed that the Bacteroides and Bacteroides and Prevotella enterotype. Partial correlation analysis showed that lipopolysaccharide was closely associated with diamine oxidase, tumor necrosis factor-alpha, and Gutt insulin sensitivity index after adjusting for multiple covariates. Furthermore, the level of lipopolysaccharide was found to be an independent risk factor for insulin sensitivity. CONCLUSIONS: We identified two enterotypes, Bacteroides and Prevotella, among all subjects. Our results showed that the Bacteroides enterotype was an independent risk factor for type 2 diabetes, which was due to increased levels of lipopolysaccharide causing decreased insulin sensitivity.Bacteroides and Prevotella enterotype. Partial correlation analysis showed that lipopolysaccharide was closely associated with diamine oxidase, tumor necrosis factor-alpha, and Gutt insulin sensitivity index after adjusting for multiple covariates. Furthermore, the level of lipopolysaccharide was found to be an independent risk factor for insulin sensitivity. Bacteroides and.

Functional analyses of an axonemal inner-arm dynein complex in the bloodstream form of Trypanosoma brucei uncover its essential role in cytokinesis initiation.

The flagellated eukaryote Trypanosoma brucei alternates between the insect vector and the mammalian host and proliferates through an unusual mode of cell division. Cell division requires flagellum motility-generated forces, but flagellum motility exerts distinct effects between different life cycle forms. Motility is required for the final cell abscission of the procyclic form in the insect vector, but is necessary for the initiation of cell division of the bloodstream form in the mammalian host. The underlying mechanisms remain elusive. Here we carried out functional analyses of a flagellar axonemal inner-arm dynein complex in the bloodstream form and investigated its mechanistic role in cytokinesis initiation. We showed that the axonemal inner-arm dynein heavy chain TbIAD5-1 and TbCentrin3 form a complex, localize to the flagellum, and are required for viability in the bloodstream form. We further demonstrated the interdependence between TbIAD5-1 and TbCentrin3 for maintenance of protein stability. Finally, we showed that depletion of TbIAD5-1 and TbCentrin3 arrested cytokinesis initiation and disrupted the localization of multiple cytokinesis initiation regulators. These findings identified the essential role of an axonemal inner-arm dynein complex in cell division, and provided molecular insights into the flagellum motility-mediated cytokinesis initiation in the bloodstream form of T. brucei.

CRL4WDR1 Controls Polo-like Kinase Protein Abundance to Promote Bilobe Duplication, Basal Body Segregation and Flagellum Attachment in Trypanosoma brucei.

The Polo-like kinase homolog in Trypanosoma brucei, TbPLK, plays essential roles in basal body segregation, flagellum attachment and cytokinesis. The level of TbPLK protein is tightly controlled, but the underlying mechanism remains elusive. Here, we report a Cullin-RING ubiquitin ligase composed of Cullin4, the DNA damage-binding protein 1 homolog TbDDB1 and a WD40-repeat protein WDR1 that controls TbPLK abundance in the basal body and the bilobe. WDR1, through its C-terminal domain, interacts with the PEST motif in TbPLK and, through its N-terminal WD40 motif, binds to TbDDB1. Depletion of WDR1 inhibits bilobe duplication and basal body segregation, disrupts the assembly of the new flagellum attachment zone filament and detaches the new flagellum. Consistent with its role in TbPLK degradation, depletion of WDR1 causes excessive accumulation of TbPLK in the basal body and the bilobe, leading to continuous phosphorylation of TbCentrin2 in the bilobe at late cell cycle stages. Together, these results identify a novel WD40-repeat protein as a TbPLK receptor in the Cullin4-DDB1 ubiquitin ligase complex for degrading TbPLK in the basal body and the bilobe after the G1/S cell cycle transition, thereby promoting bilobe duplication, basal body separation and flagellum-cell body adhesion.

Insight into mechanism of lanthanum (III) induced damage to plant photosynthesis.

A great deal of literature is available regarding the environmental and ecological effects of rare earth element pollution on plants. These studies have shown that excess lanthanum (La) (III) in the environment can inhibit plant growth and even cause plant death. Moreover, inhibition of plant photosynthesis is known to be one of the physiological bases of these damages. However, the mechanism responsible for these effects is still unclear. In this study, the mechanism of La(III)-induced damage to plant photosynthesis was clarified from the viewpoint of the chloroplast ultrastructure, the contents of chloroplast mineral elements and chlorophyll, the transcription of chloroplast ATPase subunits and chloroplast Mg(2+)-ATPase activity, in which rice was selected as a study object. Following treatment with low level of La(III), the chloroplast ultrastructure of rice was not changed, and the contents of chloroplast mineral elements (Mg, P, K, Ca, Mn, Fe, Ni, Cu, and Zn) increased, but the chlorophyll content did not change significantly. Moreover, the transcription of chloroplast ATPase subunits, chloroplast Mg(2+)-ATPase activity, the net photosynthetic rate and growth indices increased. Following treatment with high levels of La(III), the chloroplast ultrastructure was damaged, chloroplast mineral elements (except Cu and Zn) and chlorophyll contents decreased, and the transcription of chloroplast ATPase subunits, chloroplast Mg(2+)-ATPase activity, the net photosynthetic rate and growth indices decreased. Based on these results, a possible mechanism of La(III)-induced damage to plant photosynthesis was proposed to provide a reference for scientific evaluation of the potential ecological risk of rare earth elements in the environment.

A Novel Basal Body Protein That Is a Polo-like Kinase Substrate Is Required for Basal Body Segregation and Flagellum Adhesion in Trypanosoma brucei.

The Polo-like kinase (PLK) in Trypanosoma brucei plays multiple roles in basal body segregation, flagellum attachment, and cytokinesis. However, the mechanistic role of TbPLK remains elusive, mainly because most of its substrates are not known. Here, we report a new substrate of TbPLK, SPBB1, and its essential roles in T. brucei. SPBB1 was identified through yeast two-hybrid screening with the kinase-dead TbPLK as the bait. It interacts with TbPLK in vitro and in vivo, and is phosphorylated by TbPLK in vitro. SPBB1 localizes to both the mature basal body and the probasal body throughout the cell cycle, and co-localizes with TbPLK at the basal body during early cell cycle stages. RNAi against SPBB1 in procyclic trypanosomes inhibited basal body segregation, disrupted the new flagellum attachment zone filament, detached the new flagellum, and caused defective cytokinesis. Moreover, RNAi of SPBB1 confined TbPLK at the basal body and the bilobe structure, resulting in constitutive phosphorylation of TbCentrin2 at the bilobe. Altogether, these results identified a basal body protein as a TbPLK substrate and its essential role in promoting basal body segregation and flagellum attachment zone filament assembly for flagellum adhesion and cytokinesis initiation.

Photosynthesis, chlorophyll fluorescence characteristics, and chlorophyll content of soybean seedlings under combined stress of bisphenol A and cadmium.

Bisphenol A (BPA) is ubiquitous in the environment because of its continual application in plastics and the epoxy resin industry. Cadmium (Cd) is a highly toxic heavy metal element mainly used in smelting, electroplating, and plastic and dye manufacturing. Pollution as a result of BPA and Cd exists simultaneously in many agricultural regions. However, little information is available regarding the combined effects of BPA and Cd on plants. The combined effects of BPA and Cd on the photosynthesis, chlorophyll fluorescence, and chlorophyll content of soybean seedlings were investigated using noninvasive technology. Combined treatment with 1.5 mg/L BPA and 0.2 mg/L Cd synergistically improved the net photosynthetic rate (Pn ), initial fluorescence (F0 ), maximal photochemical efficiency (Fv /Fm ), effective quantum yield of photosystem II (ΦPSII ), photosynthetic electron transport rate (ETR), and chlorophyll content. Combined treatment with 1.5 mg/L BPA and 3.0 mg/L Cd increased the F0 and decreased the Pn , Fv /Fm , ΦPSII , and ETR, whereas BPA and Cd exhibited an antagonistic effect. Furthermore, combined treatment with 17.2/50.0 mg/L BPA and 3.0/10.0 mg/L Cd synergistically decreased the Pn , Fv /Fm , ΦPSII , ETR, and chlorophyll content, although it increased the F0 . Finally, the effects of BPA and Cd on photosynthesis, chlorophyll fluorescence, and chlorophyll content ceased when BPA stress was stopped.

Combined effects of lead and acid rain on photosynthesis in soybean seedlings.

To explore how lead (Pb) and acid rain simultaneously affect plants, the combined effects of Pb and acid rain on the chlorophyll content, chlorophyll fluorescence reaction, Hill reaction rate, and Mg(2+)-ATPase activity in soybean seedlings were investigated. The results indicated that, when soybean seedlings were treated with Pb or acid rain alone, the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, and maximal photochemical efficiency (F(v)/F(m)) were decreased, while the initial fluorescence (F 0) and maximum quantum yield (Y) were increased, compared with those of the control. The combined treatment with Pb and acid rain decreased the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, F(v)/F(m), and Y and increased F 0 in soybean seedlings. Under the combined treatment with Pb and acid rain, the two factors showed additive effects on the chlorophyll content in soybean seedlings and exhibited antagonistic effects on the Hill reaction rate. Under the combined treatment with high-concentration Pb and acid rain, the two factors exhibited synergistic effects on the Mg(2+)-ATPase activity, F 0, F v/F m, as well as Y. In summary, the inhibition of the photosynthetic process is an important physiological basis for the simultaneous actions of Pb and acid rain in soybean seedlings.