Gut Microbiota-Derived 3-Hydroxybutyrate Blocks GPR43-Mediated IL6 Signaling to Ameliorate Radiation Proctopathy.

Radiation proctopathy (RP) is a common complication of radiotherapy for pelvic malignancies with high incidence. RP accompanies by microbial dysbiosis. However, how the gut microbiota affects the disease remains unclear. Here, metabolomics reveals that the fecal and serous concentrations of microbiota-derived 3-hydroxybutyrate (3HB) are significantly reduced in RP mice and radiotherapeutic patients. Moreover, the concentration of 3HB is negatively associated with the expression of proinflammatory IL6 that is increased along with the severity of radiation damage. 3HB treatment significantly downregulates IL6 expression and alleviates IL6-mediated radiation damage. Irradiated cell-fecal microbiota co-culture experiments and in vivo assays show that such a radioprotection of 3HB is mediated by GPR43. Microbiome analysis reveals that radiation leads to a distinct bacterial community compared to untreated controls, in which Akkermansia muciniphila is significantly reduced in RP mice and radiotherapeutic patients and is associated with lower 3HB concentration. Gavage of A. muciniphila significantly increases 3HB concentration, downregulates GPR43 and IL6 expression, and ameliorates radiation damage. Collectively, these results demonstrate that the gut microbiota, including A. muciniphila, induce higher concentrations of 3HB to block GPR43-mediated IL6 signaling, thereby conferring radioprotection. The findings reveal a novel implication of the gut-immune axis in radiation pathophysiology, with potential therapeutic applications.

A high-fat diet promotes cancer progression by inducing gut microbiota-mediated leucine production and PMN-MDSC differentiation.

A high-fat diet (HFD) is a high-risk factor for the malignant progression of cancers through the disruption of the intestinal microbiota. However, the role of the HFD-related gut microbiota in cancer development remains unclear. This study found that obesity and obesity-related gut microbiota were associated with poor prognosis and advanced clinicopathological status in female patients with breast cancer. To investigate the impact of HFD-associated gut microbiota on cancer progression, we established various models, including HFD feeding, fecal microbiota transplantation, antibiotic feeding, and bacterial gavage, in tumor-bearing mice. HFD-related microbiota promotes cancer progression by generating polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Mechanistically, the HFD microbiota released abundant leucine, which activated the mTORC1 signaling pathway in myeloid progenitors for PMN-MDSC differentiation. Clinically, the elevated leucine level in the peripheral blood induced by the HFD microbiota was correlated with abundant tumoral PMN-MDSC infiltration and poor clinical outcomes in female patients with breast cancer. These findings revealed that the "gut-bone marrow-tumor" axis is involved in HFD-mediated cancer progression and opens a broad avenue for anticancer therapeutic strategies by targeting the aberrant metabolism of the gut microbiota.

Cerebral arteriopathy and ischemic stroke in a pediatric MYH11 patient.

OBJECTIVES: Mutations in the MYH11 gene result in smooth muscle cell dysfunction and are associated with familial thoracic aortic aneurysms and dissection. We describe a pediatric patient with a stroke and a pathogenic MYH11 IVS32G>A mutation, and a phenotype similar to ACTA2. METHODS: A proband girl with an acute ischemic stroke underwent genetic analysis and 7T high-resolution MRI. RESULTS: A 12-year-old girl presented with a right middle cerebral artery occlusion. She received thrombolysis and underwent mechanical thrombectomy. An extensive stroke work-up was negative. A three-generation pedigree showed a splice site mutation of MYH11 IVS32G>A of the proband and three more family members. A 7T-MRI showed "broomstick-like" straightening of distal arterial segments, a V-shaped anterior corpus callosum and a post-stroke cystic area of encephalomalacia. This vascular appearance and parenchymal abnormalities typically present in patients with an ACTA2 phenotype. 7T-MRI also demonstrated thickening of the right middle cerebral arterial wall. DISCUSSION: This case suggests that MYH11 patients may have a similar angiographic and brain parenchymal phenotype to patients with ACTA2 mutations. This is the first report of arterial wall thickening in a MYH11 stroke patient using 7T-MRI. Patients with MYH11 mutations may display a focal cerebral steno-occlusive arteriopathy that may lead to stroke.

Enhancing the dewaterability of waste activated sludge by the combined ascorbic acid and zero-valent iron/persulfate system.

In this work, a reducing/chelating agent, ascorbic acid (H2A) was introduced to the traditional zero-valent iron (Fe0)/persulfate (PS) process for waste activated sludge dewatering. The experimental data indicated that H2A-Fe0/PS process significantly enhanced the dewatering performance of sludge and enhanced the oxidation efficiency of Fe0-PS treatment. Under optimal conditions, the capillary suction time ratio before and after treatment (CST0/CST) of H2A-Fe0/PS treated sludge increased by 118% and 31.3% compared with untreated sludge and Fe0-PS treated sludge, respectively. The mechanism investigations revealed that the H2A-Fe0/PS induced excellent enhancement for sludge dewaterability could be credited to the reduction and chelating capacity of ascorbic acid. Free radicals including SO4•-, O2•- and •OH produced in the H2A-Fe0/PS process destroyed proteinaceous components and humic substances in sludge extracellular polymeric substances (EPS), thus reducing the negative charge and water holding capacity of sludge, improving the sludge rheological properties. As a result, the dewatering performance of sludge has been significantly improved.

Postoperative cognitive dysfunction after endovascular treatments for unruptured intracranial aneurysms: A pilot study.

OBJECTIVE: Post operative cognitive dysfunction (POCD) has been widely observed after major surgery, particularly in elderly patients with general anesthesia (GA). However, a specific unanswered question is whether different approaches to anesthetic managements are associated with different cognitive outcomes after endovascular treatments for unruptured intracranial aneurysms (UIAs). The purpose of this study is to assess the correlation of POCD with GA versus monitored anesthesia care (MAC). METHODS: We performed a pragmatic, prospective study to assess the association between different anesthetic approaches and POCD. We compared the pre- and post-procedural Montreal Cognitive Assessment (MoCA) scores in patients with normal cognition who underwent treatments of UIAs with various endovascular methods, using either GA or MAC. RESULTS: A total of 23 patients with UIAs were enrolled in the study. Seven (30.4%) and sixteen (69.6%) UIAs were treated without perioperative complications under GA or MAC, respectively. There was a significant decline in the post-procedural MoCA score under GA (mean difference = 1.14; 95% confidence interval = [0.42-1.87], P < 0.01). By contrast, there was no significant difference of MoCA score between pre- and post-procedure under MAC (mean difference = 0.19; 95% confidence interval = [-0.29-0.67], P = 0.59). CONCLUSIONS: Treating UIAs using MAC was associated with a decrease in POCD as compared to GA in patients undergoing endovascular treatments for UIAs with normal cognition. Larger randomized studies are needed to confirm these findings.

Absolute configuration of polypropionate derivatives: Decempyrones A-J and their MptpA inhibition and anti-inflammatory activities.

Under guidance of 1H NMR, ten new polypropionate derivatives, decempyrones A-J (1-10) along with two known analogues (11 and 12), were isolated from the marine-derived fungusFusarium decemcellulare SYSU-MS6716. The planar structures were elucidated on the basis of extensive spectroscopic analyses (1D and 2D NMR, and HR-ESIMS). The absolute configuration of the chiral centers in the side chain is a major obstacle for the structure identification of natural polypropionate derivatives. Herein, the J-based configurational analysis (JBCA), chemical degradation, geminal proton rule, and the modified Mosher's method were adopted to fix their absolute configurations in the side chain. Compounds 3 and 10 exhibited potent anti-inflammatory activity by inhibiting the production of NO in RAW264.7 cells activated by lipopolysaccharide with IC50values 22.4 ± 1.8 and 21.7 ± 1.1 µM. In addition, compounds 3 and 10 displayed MptpA inhibitory activity with an IC50 value of 19.2 ± 0.9 and 33.1 ± 2.9 µM. Structure-activity relationships of the polypropionate derivatives were discussed.

High salt diet may promote progression of breast tumor through eliciting immune response.

OBJECTIVE: Dietary patterns are believed to regulate tumor progression by altering the tumor microenvironment. Of note, a high salt diet is a risk factor for various diseases. However, the role of high salt intake in the progression of cancers remains unknown. METHODS: We constructed an in vivo high salt diet model in MMTV-PyVT mice with spontaneous tumor-forming properties to explore the role of a high salt diet in the progression of breast cancer as well as the modulation of the tumor microenvironment. Also, in vitro experiments were performed to understand the mechanism. RESULTS: High salt diet accelerated the development (P < 0.05) and lung metastasis (P < 0.05) of breast cancer in MMTV-PyVT mice, compared to the normal diet model. Moreover, higher frequency of Th17 cells in circulation, tumor tissue and draining lymph node tissue were observed in the high salt diet model (P < 0.05 for all). In vitro, co-culture with Th17 cells facilitated the proliferation, migration and invasion of MCF-7 human breast cancer cells, while these enhanced aggressive behaviors could be reversed by application of 1,25-vitamin D3 which could inhibit the differentiation of Th17 cells (P < 0.001 for all). In vitro, co-culture with Th17 cells activated MAPK signaling in MCF-7 cells (P < 0.001 for all). Consistently, activated MAPK/ERK signaling was observed by immunohistochemistry in breast cancer cell nodes in the high salt diet model (P < 0.05 for all). Mechanistically, higher level of IL-17F could be detected in breast tumors and serum from the high salt diet model through qRT-PCR and ELISA (P < 0.05 for all). IL-17F treatment facilitated the proliferation, migration and invasion of MCF-7 human breast cancer cells and activated MAPK/ERK signaling in MCF-7 cells (P < 0.001 for all). Moreover, the tumor-promoting function induced by Th17 cells and IL-17F could be inhibited by the administration of ERK inhibitor (sch772894) (P < 0.001 for all). Lastly, high concentration NaCl-induced Th17 cells promoted the proliferation, migration and invasion of MCF-7 human breast cancer cells and activated MAPK/ERK signaling in MCF-7 cells which could be inhibited by neutralizing anti-IL-17F (P < 0.001 for all). CONCLUSION: High salt intake accelerates the growth of breast cancer and facilitates lung metastasis, as well as increases the level of Th17 cells. Increased Th17 cells might promote the growth of breast cancer via the secretion of IL-17F to activate the MAPK signaling pathway in breast cancer cells.

Polypropionate Derivatives with Mycobacterium tuberculosis Protein Tyrosine Phosphatase B Inhibitory Activities from the Deep-Sea-Derived Fungus Aspergillus fischeri FS452.

Fiscpropionates A-F (1-6), six new polypropionate derivatives featuring an unusual long hydrophobic chain, were isolated from the deep-sea-derived fungus Aspergillus fischeri FS452. Their structures were elucidated on the basis of spectroscopic analysis, and the absolute configurations were determined by J-HMBC analysis, electronic circular dichroism (ECD) calculations, and the modified Mosher's method. This is the first discovery of polypropionates from marine-derived fungi, and compounds 4 and 5 represent the first examples of polypropionate derivatives containing a 3-hydroxypiperidin-2-one as part of an imide linkage. In addition, compounds 1-4 exhibited significant inhibitory activities against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with the IC50 values of 5.1, 12, 4.0, and 11 µM, respectively. Enzyme kinetic experiments suggested that they all acted through a noncompetitive mechanism. A preliminary structure-activity relationship is discussed.

The Legionella pneumophila effector WipA disrupts host F-actin polymerisation by hijacking phosphotyrosine signalling.

The major virulence determinant of Legionella pneumophila is the type IVB secretion system (T4BSS), which delivers approximately 330 effector proteins into the host cell to modulate various cellular processes. However, the functions of most effector proteins remain unclear. WipA, an effector, was the first phosphotyrosine phosphatase of Legionella with unknown function. In this study, we found that WipA induced relatively strong growth defects in yeast in a phosphatase activity-dependent manner. Phosphoproteomics data showed that WipA was likely involved into endocytosis, FcγR-mediated phagocytosis, tight junction, and regulation of actin cytoskeleton pathways. Western blotting further confirmed WipA dephosphorylates several proteins associated with actin polymerisation, such as p-N-WASP, p-ARP3, p-ACK1, and p-NCK1. Thus, we hypothesised that WipA targets N-WASP/ARP2/3 complex signalling pathway, leading to disturbance of actin polymerisation. Indeed, we demonstrated that WipA inhibits host F-actin polymerisation by reducing the G-actin to F-actin transition during L. penumophila infection. Furthermore, the intracellular proliferation of wipA/legK2 double mutant was significantly impaired at the late stage of infection, although the absence of WipA does not confer any further effect on actin polymerisation to the legK2 mutant. Collectively, this study provides unique insights into the WipA-mediated regulation of host actin polymerisation and assists us to elucidate the pathogenic mechanisms of L. pnuemophila infection.

Peptides and polyketides isolated from the marine sponge-derived fungus Aspergillus terreus SCSIO 41008.

Two new isomeric modified tripeptides, aspergillamides C and D (compounds 1 and 2), together with fifteen known compounds (compounds 3-17), were obtained from the marine sponge-derived fungus Aspergillus terreus SCSIO 41008. The structures of the new compounds, including absolute configurations, were determined by extensive analyses of spectroscopic data (NMR, MS, UV, and IR) and comparisons between the calculated and experimental electronic circular dichroism (ECD) spectra. Butyrolactone I (compound 11) exhibited strong inhibitory effects against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with the IC50 being 5.11 ± 0.53 µmol·L-1, and acted as a noncompetitive inhibitor based on kinetic analysis.

The Ralstonia solanacearum effector RipN suppresses plant PAMP-triggered immunity, localizes to the endoplasmic reticulum and nucleus, and alters the NADH/NAD+ ratio in Arabidopsis.

Ralstonia solanacearum, one of the most destructive plant bacterial pathogens, delivers an array of effector proteins via its type III secretion system for pathogenesis. However, the biochemical functions of most of these proteins remain unclear. RipN is a type III effector with unknown function(s) from the pathogen R. solanacearum. Here, we demonstrate that RipN is a conserved type III effector found within the R. solanacearum species complex that contains a putative Nudix hydrolase domain and has ADP-ribose/NADH pyrophosphorylase activity in vitro. Further analysis shows that RipN localizes to the endoplasmic reticulum (ER) and nucleus in Nicotiana tabacum leaf cells and Arabidopsis protoplasts, and truncation of the C-terminus of RipN results in a loss of nuclear and ER targeting. Furthermore, the expression of RipN in Arabidopsis suppresses callose deposition and the transcription of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) marker genes under flg22 treatment, and promotes bacterial growth in planta. In addition, the expression of RipN in plant cells alters NADH/NAD+ , but not GSH/GSSG, ratios, and its Nudix hydrolase activity is indispensable for such biochemical function. These results suggest that RipN acts as a Nudix hydrolase, alters the NADH/NAD+ ratio of the plant and contributes to R. solanacearum virulence by suppression of PTI of the host.

Two new bioactive steroids from a mangrove-derived fungus Aspergillus sp.

Two unusual naturally Diels-Alder additive steroids, ergosterdiacids A and B (1 and 2), constructing a 6/6/6/6/5 pentacyclic steroidal system, together with three known compounds (3-5) were obtained from the mangrove-derived fungus Aspergillus sp. Their structures were elucidated based on the comprehensive spectroscopic analysis, including 1D, 2D NMR and HRESIMS, as well as the quantum chemical ECD calculations. The plausible biosynthetic pathways of 1 and 2 were discussed. In the bioactivity assays, 1 and 2 exhibited potential in vitro inhibition activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with an IC50 value of 15.1 and 30.1 µM, respectively. The inhibitory kinetic experiments indicated that both of them acted via a noncompetitive inhibition mechanism. Moreover, 1 and 2 showed strong in vitro anti-inflammatory effects by suppressing the NO production at 4.5 and 3.6 µM, respectively.

The Ralstonia solanacearum effector RipAK suppresses plant hypersensitive response by inhibiting the activity of host catalases.

The destructive bacterial pathogen Ralstonia solanacearum delivers effector proteins via a type-III secretion system for its pathogenesis of plant hosts. However, the biochemical functions of most of these effectors remain unclear. RipAK of R. solanacearum GMI1000 is a type-III effector with unknown functions. Functional analysis demonstrated that in tobacco leaves, ripAK knockout bacteria produced an obvious hypersensitive response; also, infected tissues accumulated reactive oxygen species in a shorter period postinfection, compared with wild type. This strongly indicates that RipAK can inhibit hypersensitive response during infection. Further analysis showed that RipAK localizes to peroxisomes and interacts with host catalases (CATs) in plant cells. Truncation of 2 putative domains of RipAK caused it to fail to target the peroxisome and fail to interact with AtCATs, suggesting that RipAK localization depends on its interaction with CATs. Furthermore, heterologous expression of RipAK inhibited CAT activity in vivo and in vitro. Finally, compared with the ripAK mutant, infection with a bacterial strain overexpressing RipAK inhibited the transcription of many immunity-associated genes in infected tobacco leaves at 2- and 4-hr postinfection, although mRNA levels of NtCAT1 were upregulated. These data indicate that GMI1000 suppresses hypersensitive response by inhibiting host CATs through RipAK at early stages of infection.

Sclerotiorin inhibits protein kinase G from Mycobacterium tuberculosis and impairs mycobacterial growth in macrophages.

As a eukaryotic-like Ser/Thr protein kinase, Mycobacterium tuberculosis virulent effector protein kinase G (PknG) mediates mycobacterial survival by regulating bacterial cell metabolic processes and preventing phagosome-lysosome fusion in host macrophages. Targeting PknG is an effective strategy for development of anti-tuberculosis (TB) drugs. In the study, we found that sclerotiorin, derived from marine fungi from the South China Sea, exhibited moderately strong inhibitory effects on recombinant PknG, with an IC50 value of 76.5 µM, and acted as a non-competitive inhibitor. The dissociation constant (KD) of sclerotiorin determined by MST was 11.4 µM, demonstrating a moderate binding strength between them. Sclerotiorin could substantially impair the mycobacterial survival in infected macrophages while the macrophage viability remained unaffected, though it did not inhibit the mycobacterial growth in culture. When sclerotiorin was used in combination with rifampicin, intracellular mycobacterial growth decreased as sclerotiorin concentration increased. Docking analysis suggested a binding mechanism of inhibition with performing interactions with the P-loop and catalytic loop of PknG. In summary, we reported that sclerotiorin had moderately strong PknG inhibitory activity, but no cytotoxicity, and it could substantially decrease the mycobacterial growth inside macrophages, suggesting that sclerotiorin has potential to supplement antibiotic therapy for TB.

Cytotoxic and Antibacterial Preussomerins from the Mangrove Endophytic Fungus Lasiodiplodia theobromae ZJ-HQ1.

Two new chlorinated preussomerins, chloropreussomerins A and B (1 and 2), together with nine known preussomerin analogues, 3-11, were obtained from the endophytic fungus Lasiodiplodia theobromae ZJ-HQ1. Their structures were elucidated by a combination of spectroscopic analyses. The absolute configurations of 1 and 2 were both determined by single-crystal X-ray diffraction using Cu Kα radiation. Chloropreussomerins A and B (1 and 2) are the first chlorinated compounds in the preussomerin family, and preussomerin M (3) is reported for the first time as a natural product. Compounds 1 and 2 showed potent in vitro cytotoxicity against A549 and MCF-7 human cancer cell lines, with IC50 values ranging from 5.9 to 8.9 µM, and compounds 4-7 exhibited significant bioactivity against A549, HepG2, and MCF-7 human cancer cell lines, with IC50 values of 2.5-9.4 µM. In the antibacterial assay, compounds 1, 2, 5-7, and 11 exhibited significant activities against Staphylococcus aureus, with MIC values between 1.6 and 13 µg/mL.

ClpP-deletion impairs the virulence of Legionella pneumophila and the optimal translocation of effector proteins.

BACKGROUND: The opportunistic bacterial pathogen Legionella pneumophila uses substrate effectors of Dot/Icm type IVB secretion system (T4BSS) to accomplish survival and replication in amoebae cells and mammalian alveolar macrophages. During the conversion between its highly resistant, infectious dormant form and vigorously growing, uninfectious replicative form, L. pneumophila utilizes a complicated regulatory network in which proteolysis may play a significant role. As a highly conserved core protease, ClpP is involved in various cellular processes as well as virulence in bacteria, and has been proved to be required for the expression of transmission traits and cell division of L. pneumophila. RESULTS: The clpP-deficient L. pneumophila strain failed to replicate and was digested in the first 3 h post-infection in mammalian cells J774A.1. Further investigation demonstrates that the clpP deficient mutant strain was unable to escape the endosome-lysosomal pathway in host cells. We also found that the clpP deficient mutant strain still expresses T4BSS components, induces contact-dependent cytotoxicity and translocate effector proteins RalF and LegK2, indicating that its T4BSS was overall functional. Interestingly, we further found that the translocation of several effector proteins is significantly reduced without ClpP. CONCLUSIONS: The data indicate that ClpP plays an important role in regulating the virulence and effector translocation of Legionella pneumophila.

Lasiodiplodins from mangrove endophytic fungus Lasiodiplodia sp. 318.

Four new lasiodiplodins (1-4), together with three known analogues, have been isolated from a mangrove endophytic fungus, Lasiodiplodia sp. 318#. Their structures were elucidated by spectroscopic techniques. Cytotoxic activities of compounds 1-7 were evaluated in vitro against human cancer lines THP1, MDA-MB-435, A549, HepG2 and HCT-116. Compound 4 exhibited moderate cytotoxic activities.

A New Terminal Cyano Group-containing Benzodiazepine Alkaloid from the Mangrove Endophytic Fungus Penicillium sp. .

A new benzodiazepine alkaloid containing terminal cyano group has been isolated from a mangrove endophytic fungus, Penicillium 299#. Structure elucidation was determined by 1D and 2D NMR spectroscopy and the absolute configuration was determined by electronic circular dichroism (ECD). The new compound showed no cytotoxic activities in vitro against human cancer lines MDA-MB-435, HepG2, HCT-116, and Calu-3.

Preparation of D-limonene oil-in-water nanoemulsion from an optimum formulation.

D-limonene in water nanoemulsion is prepared from an optimum formulation by low energy process at room temperature. The phase behavior of d-limonene/isotridecanol ethoxylate-6/ isopropyl alcohol /water system is systematically investigated to identify the optimum formulation. The microstructure of intermediate phases has been characterized by optical microscope and small angle X-ray diffraction. The microstructure of formulation concentrate has been further determined by means of electrical conductivity. The droplet size of nanoemulsion has been determined by light scattering and correlated with their microstructure. The results show that d-limonene nanoemulsion with droplet size of ca. 40 nm is obtained via the addition of the optimum formulation, which is a microemulsion, directly into water. This process involves composition change from a bicontinuous structure.

Serum anti-Müllerian hormone and insulin resistance in the main phenotypes of non-obese polycystic ovarian syndrome women in China.

OBJECTIVES: Objective was to evaluate anti-Müllerian-hormone (AMH) and parameters for insulin resistance (IR) in the main phenotypes of polycystic ovarian syndrome (PCOS), and to investigate their correlation for the first time in non-obese Chinese women. METHODS: Within this prospective study, 160 PCOS cases and 40 healthy women, matched by age and BMI, were included. In four groups (n = 40) according to the four phenotypes of PCOS by definition of the National Institute of Health (2012), AMH, ovarian volume and number of follicles 2-9 mm were assessed as well as insulin resistance indexes (Homeostatic Model Assessment) (HOMA-IR) and Quantitative Insulin Sensitivity Check Index (QUICKI). RESULTS: AMH levels were higher in PCOS than in controls, with differences comparing the phenotypes, highest in the group with all three criteria for PCOS. However, for HOMA-IR and QUICKI and correlation to AMH no significant differences were found. CONCLUSIONS: AMH is a useful parameter to assess in the different phenotypes the severity of PCOS, and to compare with healthy women, for the first time demonstrated in Chinese patients. In contrast, the parameters for IR and their relation to AMH did not show clear differences comparing the four phenotypes, and need further investigation.