Gut commensal Christensenella minuta modulates host metabolism via acylated secondary bile acids.

A strong correlation between gut microbes and host health has been observed in numerous gut metagenomic cohort studies. However, the underlying mechanisms governing host-microbe interactions in the gut remain largely unknown. Here we report that the gut commensal Christensenella minuta modulates host metabolism by generating a previously undescribed class of secondary bile acids with 3-O-acylation substitution that inhibit the intestinal farnesoid X receptor. Administration of C. minuta alleviated features of metabolic disease in high fat diet-induced obese mice associated with a significant increase in these acylated bile acids, which we refer to as 3-O-acyl-cholic acids. Specific knockout of intestinal farnesoid X receptor in mice counteracted the beneficial effects observed in their wild-type counterparts. Finally, we showed that 3-O-acyl-CAs were prevalent in healthy humans but significantly depleted in patients with type 2 diabetes. Our findings indicate a role for C. minuta and acylated bile acids in metabolic diseases.

MicroRNA­30a­5p regulates cypermethrin-induced apoptosis of Sertoli cells by targeting KLF9 in vitro.

Cypermethrin (CYP) has been identified as one kind of endocrine-disrupting chemicals (EDCs) to induce male reproduction damage. This study aimed to investigate the effects and mechanisms of miR-30a-5p on CYP induced apoptosis of TM4 mouse Sertoli cells in vitro. In the present study, 0 µM, 10 µM, 20 µM, 40 µM and 80 µM CYP were used to treat TM4 cells for 24 h. The apoptosis of TM4 cells, the expression level of miR-30a-5p, the protein expressions and the interaction between miR-30a-5p and KLF9 were detected by flow cytometry, quantitative Real-Time PCR, Western blot and luciferase reporter assays. CYP induced apoptosis of TM4 cells, inhibited expression of miR-30a-5p in TM4 cells, and overexpression of miR-30a-5p partially recovered CYP induced cells apoptosis. Furthermore, KLF9 was a potential downstream target of miR-30a-5p predicted by publicly available databases. KLF9 expression level in TM4 cells was significantly elevated after treatment with CYP, and the induction was inhibited by miR-30a-5p mimics transfection. Meanwhile, dual-luciferase reporter assay demonstrated that miR-30a-5p directly targeted KLF9-3'UTR. Moreover, in the presence of CYP, the apoptosis regulator p53 expression was also increased in TM4 cells. Overexpression miR-30a-5p or down-regulation of KLF9 both attenuated the induction of CYP on p53 expression. Overall, the present study demonstrated that miR-30a-5p regulated CYP induced TM4 cells apoptosis by targeting KLF9/p53 axis.

BMP4 Regulates EMT to be Involved in non-Syndromic Cleft lip With or Without Palate.

OBJECTIVE: In the previous study, we identified bone morphogenetic protein 4 (BMP4) responsible for non-syndromic cleft lip with or without cleft palate (NSCL/P). We aimed to elucidate the effects and mechanisms of BMP4 on epithelial-mesenchymal transition (EMT) through Smad1 signaling pathway to be involved in NSCL/P. METHODS: The human oral epidermoid carcinoma cells (KBs) were transfected with plasmids or small interfering RNA (siRNA) to build the models. The migration of the cells was evaluated by transwell assay. Western blotting and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the expressions of BMP4, E-cadherin, N-cadherin, EMT-related transcription factors snal1 and snal2, matrix metalloproteinase 2 (MMP2), MMP9, Smad1, and phosphorylated Smad1. RESULTS: In the overexpression group, the migration number of cells was increased significantly. The protein expression of E-cadherin was decreased significantly, while the protein expression level of the N-cadherin was increased significantly. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly higher. The expression level of Smad1 was not significantly changed, while the phosphorylation of Smad1 was significantly increased. In the BMP4-siRNA group, the migrating number cells was significantly decreased. The protein expression of E-cadherin was increased significantly, while the expression of N-cadherin was significantly decreased. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly lower than that of the control group. The expressions of Smad1 and phosphorylation of Smad1 were not significantly changed. CONCLUSIONS: BMP4 enhances cell migration and promotes cell EMT through Smad1 signaling pathway. Abnormal BMP4 mediates migration and EMT through other relevant signaling pathways resulting in NSCL/P. The study provides new insight into the mechanisms of NSCL/P associated with BMP4.n.

Abnormalities of hsa-mir-16 and hsa-mir-124 Affect Mitochondrial Function and Fatty Acid Metabolism in Tetralogy of Fallot.

BACKGROUND: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease in clinical practice. It is mainly due to cardiovascular hypoplasia during embryonic development. The study aimed to find the etiology of TOF. METHODS: Through the mRNA expression profile analysis of the GSE35776 dataset, differentially expressed genes (DEGs) were found, and the functional analysis and protein-protein interaction (PPI) network analysis were then performed on DEGs. Likewise, the hub genes and functional clusters of DEGs were analyzed using the PPI network. Differentially expressed miRNAs were analyzed from the GSE35490 dataset, followed by miRNet predicted transcription factors (TFs) and target genes. The key TF-miRNA-gene interaction mechanism was explored through the found significant difference between genes and target genes. RESULTS: A total of 191 differentially expressed genes and 57 differentially expressed miRNAs were identified. The main mechanisms involved in TOF were mitochondria-related and energy metabolism- related molecules and pathways in GO and KEGG analysis. This discovery was identical in TFs and target genes. The key miRNAs, hsa-mir-16 and hsa-mir-124, were discovered by the Venn diagram. A co-expression network with the mechanism of action centered on two miRNAs was made. CONCLUSION: Hsa-mir-16 and hsa-mir-124 are the key miRNAs of TOF, which mainly regulate the expression of NT5DC1, ECHDC1, HSDL2, FCHO2, and ACAA2 involved in the conversion of ATP in the mitochondria and the metabolic rate of fatty acids (FA). Our research provides key molecules and pathways into the etiology of TOF, which can be used as therapeutic targets.

Cypermethrin inhibits proliferation of Sertoli cells through AR involving DAB2IP/PI3K/AKT signaling pathway in vitro.

Cypermethrin (CP) exhibits anti-androgenic effects through antagonism on androgen receptor (AR) activation. This study was to identify whether AR-mediated disabled 2 interacting protein (DAB2IP)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway was involved in CP-induced mouse Sertoli cells (TM4) proliferation disorder. Real-Time Cell Analysis-iCELLigence system was to measure cell proliferation. Bioinformatic analyses were performed to identify AR-regulated genes. Quantitative Real-Time PCR and western blot were to detect the genes and proteins levels in AR-mediated DAB2IP/PI3K/AKT pathway. Results showed CP suppressed TM4 proliferation and the expression of AR. Activation of AR restored the inhibition efficacy of CP on TM4 proliferation. AR regulated DAB2IP expression and phosphorylation levels of PI3K and AKT in CP-exposed TM4 cells. In addition, knockdown of DAB2IP alleviated the inhibition efficacy of CP on cell proliferation and phosphorylation of PI3K and AKT. Taken together, AR was a modulator in CP-induced inhibition of Sertoli cells proliferation by negatively regulating DAB2IP/PI3K/AKT signaling pathway. The study may provide a new insight for the mechanisms of male reproductive toxicity induced by CP.

Cypermethrin induces Sertoli cell apoptosis through mitochondrial pathway associated with calcium.

Cypermethrin, one kind of pyrethroid pesticides, has been shown to act as endocrine-disrupting chemicals (EDCs). The purpose of this study was to explore the roles of Sertoli cell apoptosis through mitochondrial pathway associated with calcium (Ca2+) in cypermethrin-induced male reproductive toxicology. The mouse Sertoli cells TM4 were cultured with 0 µM, 10 µM, 20 µM, 40 µM and 80 µM of cypermethrin. We used flow cytometry, Fluo-4 AM, western blot and JC-1 Assay Kit to examine apoptosis, intracellular Ca2+, expressions of mitochondrial apoptotic pathway-related proteins and mitochondrial membrane potential. We found cypermethrin increased apoptosis rate of TM4 cells significantly and with a significant increase in intracellular Ca2+ concentration. Cypermethrin significantly decreased the protein expressions of cytosolic B-cell lymphoma-2 (Bcl-2) and mitochondrial cytochrome c (Cyt-c). The protein expressions of cytosolic Bcl-2-associated x (Bax), Cyt-c, cleaved caspase-3, calmodulin (CaM), Ca2+/CaM-dependent protein kinases II (CaMKII) and phosphorylated CaMKII were increased significantly in cypermethrin-exposed TM4 cells. Cypermethrin decreased mitochondrial membrane potential significantly. Then, Bcl-2 family and Ca2+/CaM/CaMKII pathway participate in cypermethrin-induced homeostasis. Ca2+ overload activates mitochondrial pathway by increasing permeability of mitochondrial membrane and decreasing mitochondrial membrane potential. We suggest cypermethrin induces Sertoli cell apoptosis involving mitochondrial pathway associated with Ca2+ regulated by Bcl-2 family and Ca2+/CaM/CaMKII pathway. The study provides a new insight into mechanisms involved in cypermethrin-induced male reproductive toxicology.

Effects of small interfering RNA-mediated silencing of susceptibility genes of non-syndromic cleft lip with or without cleft palate on cell proliferation and migration.

BACKGROUND: Non-syndrome cleft lip with or without cleft palate (NSCL/P) is the most common congenital defect with a complex etiology involving both genetic and environmental factors. Our previous research has identified susceptibility genes of NSCL/P using whole-exome sequencing. The study was to determine the effects of small interfering RNA (siRNA)-mediated silencing of genes on cell proliferation and migration to confirm the roles of the genes in NSCL/P. METHODS: We silenced the genes by RNA interference (RNAi) with siRNA in human oral keratinocyte (HOK). We used the Cell Counting Kit-8 (CCK8) assay to determine cell proliferation and the wound healing assay to determine cell migration. RESULTS: Migration of HOK was inhibited by RNAi-induced silencing of adenosine triphosphate binding cassette transporter A4 (ABCA4), erythropoietin produces hepatocyte A receptor 3 (EPHA3), alpha-parvin (PARVA), and platelet-derived growth factor C (PDGFC). The change of proliferation was not found. Treated with siRNA-mediated silencing of type IV collagen (COL4A2), eukaryotic translation initiation factor 2B subunit (EIF2B3), fibroblast growth factor receptor 2 (FGFR2), kinesin family member 20B (KIF20B), ß-lactamase serine-like protein (LACTB), SEC16 homolog A (SEC16A) and thyroid adenoma target gene (THADA) had no effects on cell proliferation and migration of HOK. CONCLUSIONS: We suggest mutations of the four susceptibility genes ABCA4, EPHA3, PARVA and PDGFC are involved in NSCL/P through inhibiting cell migration. The study provides new candidates for future study of NSCL/P.

Baicalein inhibits osteosarcoma cell proliferation and invasion through the miR­183/Ezrin pathway.

Osteosarcoma (OS), a common and primary malignant bone tumor, is characterized by highly aggressive potency. Baicalein, a bioactive flavone isolated from Scutellaria baicalensis Georgi, has been shown to inhibit the progression of numerous tumors, including OS. However, the mechanisms by which baicalein protects against OS are still largely unknown. The results of the present study showed that administration of baicalein significantly inhibited the proliferation, migration and invasion and promoted apoptosis in MG­63 and Saos­2 cells. Ezrin was identified as a target gene of microRNA (miR)­183. MG­63 and Saos­2 cells treated with baicalein exhibited increased miR­183 levels and decreased Ezrin expression. Importantly, miR­183 inhibition and Ezrin overexpression abolished the effects of baicalein on MG­63 and Saos­2 cell proliferation, migration, invasion and apoptosis. Taken together, these findings suggest that baicalein inhibits the proliferation, migration and invasion and induces apoptosis in OS cells by activating the miR­183/Ezrin pathway, revealing a novel mechanism underlying anti­OS effects of baicalein.

Processive Degradation of Crystalline Cellulose by a Multimodular Endoglucanase via a Wirewalking Mode.

Processive hydrolysis of crystalline cellulose by cellulases is a critical step for lignocellulose deconstruction. The classic Trichoderma reesei exoglucanase TrCel7A, which has a closed active-site tunnel, starts each processive run by threading the tunnel with a cellulose chain. Loop regions are necessary for tunnel conformation, resulting in weak thermostability of fungal exoglucanases. However, endoglucanase CcCel9A, from the thermophilic bacterium Clostridium cellulosi, comprises a glycoside hydrolase (GH) family 9 module with an open cleft and five carbohydrate-binding modules (CBMs) and hydrolyzes crystalline cellulose processively. How CcCel9A and other similar GH9 enzymes bind to the smooth surface of crystalline cellulose to achieve processivity is still unknown. Our results demonstrate that the C-terminal CBM3b and three CBMX2s enhance productive adsorption to cellulose, while the CBM3c adjacent to the GH9 is tightly bound to 11 glucosyl units, thereby extending the catalytic cleft to 17 subsites, which facilitates decrystallization by forming a supramodular binding surface. In the open cleft, the strong interaction forces between substrate-binding subsites and glucosyl rings enable cleavage of the hydrogen bonds and extraction of a single cellulose chain. In addition, subsite -4 is capable of drawing the chain to its favored location. Cellotetraose is released from the open cleft as the initial product to achieve high processivity, which is further hydrolyzed to cellotriose, cellobiose and glucose by the catalytic cleft of the endoglucanase. On this basis, we propose a wirewalking mode for processive degradation of crystalline cellulose by an endoglucanase, which provides insights for rational design of industrial cellulases.

Substitution of one calcium-binding amino acid strengthens substrate binding in a thermophilic alginate lyase.

Ligand binding is sensitive to temperatures since noncovalent bonds between the binding site and ligand could be broken by heat. How metal ion-binding amino acids in alginate lyase evolve to achieve tight substrate binding in a hostile environment remains unknown. An endolytic alginate lyase AlgAT0 specifically cleaved the M-G glycosidic bond and released disaccharides as the main end product. Four conserved calcium-binding sites were predicted and the supplement of Ca2+ led to enhanced substrate binding and protein stability. Among the four conserved calcium-binding sites, one substitution of aspartate for glutamate in AlgAT0 was proved to stimulate Ca2+ affinity. This study suggested that substrate affinity of polysaccharide lyases could be improved by tight binding to Ca2+ via one amino acid substitution.

High-Tech Acupuncture for Prevention of Lifestyle Diseases-A Sino-Austrian Cooperation Research Protocol on Heart Rate Variability.

BACKGROUND: Acupuncture can not only be used for well-known diseases, but also for so-called modern lifestyle-related diseases. Using innovative methods like e.g. new analyses of heart rate variability (HRV), it is also possible to investigate diseases like burnout syndrome, ie., qi deficiency in Chinese medicine (CM). OBJECTIVE: The main object of this research protocol is to perform research on the relationship of burnout syndrome and heart rate (HR) and HRV. METHODS: A total of 175 patients with burnout syndrome (qi deficiency syndrome) in five groups and 35 healthy volunteers will be investigated. Based on random numbers generated by computer and concealed in opaque envelops, the patients will be assigned to four acupuncture groups using Zusanli (ST 36) acupuncture stimulation, Guanyuan (CV4) acupuncture stimulation, both points, and both points with Streitberger device respectively, and a moxibustion group using both points mentioned above, with 35 cases in each group. Altogether four different experiments are planned. Experiment 1 includes 70 subjects and is a comparison between a burnout group and a control group (healthy volunteers). The evaluation parameters are different scores and indices of HR and HRV. Experiment 2 includes 140 subjects and compares the efficacy of different acupuncture points. In experiment 3 (105 subjects), acupuncture and moxibustion should be compared to healthy volunteers. Experiment 4 (70 subjects) investigates the long-term therapeutic effects of acupuncture and moxibustion on the scores of qi deficiency and HR/HRV in qi deficiency patients. In both the acupuncture and moxibustion groups, a total of 10 treatments will be performed. CONCLUSIONS: The joint research aims at the scientific evaluation of CM, mainly in the field of HRV. This parameter could be a very good indicator of the state of health and can be inflfluenced by different acupuncture methods, as shown in the past.

Complete genome sequence of strain Lentibacillus amyloliquefaciens LAM0015(T) isolated from saline sediment.

The type strain Lentibacillus amyloliquefaciens LAM0015(T) with considerably highly NaCl tolerance is a member of halophiles. Here we report its genome sequence, the first to publish complete genome sequence of the Lentibacillus genus. It contains 3,858,520bp with an average GC content of 42.12%, encoding multiple valuable proteins academically and industrially. The genome sequence of strain LAM0015(T) provides basic information for further elucidation of halophilic mechanism and wider exploitation of functional genes.

Distinct roles for carbohydrate-binding modules of glycoside hydrolase 10 (GH10) and GH11 xylanases from Caldicellulosiruptor sp. strain F32 in thermostability and catalytic efficiency.

Xylanases are crucial for lignocellulosic biomass deconstruction and generally contain noncatalytic carbohydrate-binding modules (CBMs) accessing recalcitrant polymers. Understanding how multimodular enzymes assemble can benefit protein engineering by aiming at accommodating various environmental conditions. Two multimodular xylanases, XynA and XynB, which belong to glycoside hydrolase families 11 (GH11) and GH10, respectively, have been identified from Caldicellulosiruptor sp. strain F32. In this study, both xylanases and their truncated mutants were overexpressed in Escherichia coli, purified, and characterized. GH11 XynATM1 lacking CBM exhibited a considerable improvement in specific activity (215.8 U nmol(-1) versus 94.7 U nmol(-1)) and thermal stability (half-life of 48 h versus 5.5 h at 75°C) compared with those of XynA. However, GH10 XynB showed higher enzyme activity and thermostability than its truncated mutant without CBM. Site-directed mutagenesis of N-terminal amino acids resulted in a mutant, XynATM1-M, with 50% residual activity improvement at 75°C for 48 h, revealing that the disordered region influenced protein thermostability negatively. The thermal stability of both xylanases and their truncated mutants were consistent with their melting temperature (Tm), which was determined by using differential scanning calorimetry. Through homology modeling and cross-linking analysis, we demonstrated that for XynB, the resistance against thermoinactivation generally was enhanced through improving both domain properties and interdomain interactions, whereas for XynA, no interdomain interactions were observed. Optimized intramolecular interactions can accelerate thermostability, which provided microbes a powerful evolutionary strategy to assemble catalysts that are adapted to various ecological conditions.

Quantitative estimate of the effect of cellulase components during degradation of cotton fibers.

A comprehensive mechanistic kinetic model for enzymatic degradation of cotton fibers has been established based on a complete factorial experiment in combination with multivariate stepwise regression analysis. The analysis of the statistical parameter value in the model suggests that the enzymatic degradation of cotton fiber is a progressive and heterogeneous process that includes, at least, two courses that occur sequentially and then progress in parallel. Cellulose fibers were first depolymerized or solubilized by the synergism between cellobiohydrolase I (CBHI) and endoglucanase I (EGI), and then the oligomers obtained were randomly hydrolyzed into glucose by EGI and beta-glucosidase. The proposed model can be applied to the quantitative estimation of the effects of three cellulase components, CBHI, EGI, and beta-glucosidase separately, or in combination during the entire process of cellulose degradation. The validity of the proposed model has been verified by a filter paper activity assay. Its other applicability was also discussed.

In vitro assembly of R-phycoerythrin from marine red alga Polysiphonia urceolata.

Scanning tunneling microscope was used to investigate the in vitro assembly of R-phycoerythrin (R-PE) from the marine red alga Polysiphonia urceolata. The results showed that R-PE molecules assembled together by disc-to-disc while absorbing on HOPG surface, which just looked like the rods in the phycobilisomes. When the water-soluble R-PE was dissolved in 2% ethanol/water spreading solution, they could form monolayer film at the air/water interface. Similar disc-to-disc array of R-PE was constituted in the two-dimensional Langmuir-Blodgett film by the external force. It could be concluded that, apart from the key role of the linker polypeptides, the in vivo assembly of phycobiliproteins into phycobilisomes is also dependent on the endogenous properties of phycobiliprotein themselves.