CircROBO1 knockdown improves the radiosensitivity of hepatocellular carcinoma by regulating RAD21.

INTRODUCTION AND OBJECTIVES: Radioresistance is a common problem in the treatment of many cancers, including hepatocellular carcinoma (HCC). Previous studies have shown that circROBO1 is highly expressed in HCC tissues and acts as a cancer promoter to accelerate the malignant progression of HCC. However, the role and mechanism of circROBO1 in HCC radioresistance remain unclear. MATERIALS AND METHODS: CircROBO1, microRNA (miR)-136-5p and RAD21 expression levels were analyzed by quantitative real-time PCR. Cell function and radioresistance were evaluated by colony formation assay, cell counting kit 8 assay, EdU assay and flow cytometry. Protein expression was determined using western blot analysis. RNA interaction was analyzed by dual-luciferase reporter assay and RNA pull-down assay. In vivo experiments were performed by constructing mice xenograft models. RESULTS: CircROBO1 was highly expressed in HCC, and its knockdown inhibited HCC cell proliferation and promoted apoptosis to enhance cell radiosensitivity. On the mechanism, circROBO1 could serve as miR-136-5p sponge to positively regulate RAD21. MiR-136-5p inhibitor or RAD21 overexpression reversed the regulation of circROBO1 knockdown on the radiosensitivity of HCC cells. Also, circROBO1 interference improved the radiosensitivity of HCC tumors in vivo. CONCLUSIONS: CircROBO1 might be a promising target for treating HCC radioresistance.

First report of Colombian datura virus in Brugmansia suaveolens in Korea.

Brugmansia suaveolens, known as angel's trumpet, is a perennial ornamental shrub in the Solanaceae with large fragrant flowers. In June 2018, a leaf sample of B. suaveolens that showed virus-like symptoms including chlorotic spots, yellowing and mottle on leaves was collected from a greenhouse in Seongnam, South Korea for disease diagnosis (Supplementary Figure S1a, b). Disease incidence in the greenhouse was greater than 80% for about 2,000 B. suaveolens plants. To identify a causal virus, transmission electron microscopy (TEM) was used to analyze symptomatic leaf samples using leaf dips and thin section methods. Filamentous virus particles and pinwheel structures were observed, indicating the presence of a potyvirus (Supplementary Figure S1c, d). To confirm the TEM results, a symptomatic leaf sample was further analyzed by reverse-transcription polymerase chain reaction (RT-PCR) using species-specific detection primers for three potyviruses that infect Brugmansia spp.: Colombian datura virus (CDV), Brugmansia mosaic virus (BruMV), and Brugmansia suaveolens mottle virus (BsMoV) (Lucinda et al, 2008; Park et al., 2014; Verma et al., 2014). The sample was positive only for CDV. CDV is transmitted by aphids in a nonpersistent manner and mechanical inoculation and can infect plants in the Solanaceae family including tomato and tobacco (Kahn and Bartels 1968; Schubert et al. 2006; Verhoeven et al. 1996) and has been designated a quarantine virus in Korea. Additional analysis of 13 symptomatic B. suaveolens plants from the infected greenhouse found that all samples except one were infected with CDV. To isolate CDV from B. suaveolens, leaf extracts from symptomatic samples were mechanically inoculated on an assay host, Nicotiana tabacum cv. BY via three single-lesion passages followed by propagation in N. benthamiana. For the bioassay of the CDV isolate (CDV-AT-Kr), sap from infected N. benthamiana was mechanically inoculated on 31 indicator plants, including B. suaveolens (Supplementary Table S2). CDV-AT-Kr induced chlorotic local lesions, necrotic local lesions, mottle, and/or mosaic systemically in 10 Nicotiana spp., and mottle and yellowing in tomato. On inoculated B. suaveolens, te mild mottle symptom was reproduced. No symptoms were observed in pepper or Datura stramonium. These results were confirmed by RT-PCR. To characterize CDV-AT-Kr genetically, the complete genome sequence of CDV-AT-Kr was obtained by RT-PCR using specific primers (Supplementary Table S3) and deposited in GenBank (accession no. MW075268). The CDV-AT-Kr RNA consists of 9,620 nt, encoding a polyprotein of 3,076 aa. BLASTn analysis showed that CDV-AT had maximum nucleotide identities of 98.9% at the complete genome level with a CDV isolate (accession no. JQ801448) from N. tabacum in the UK. To our knowledge, this is the first report of CDV infection in B. suaveolens in Korea and the second report in the world of the complete genome sequence. As B. suaveolens is cultivated by vegetative propagation, production and maintenance of virus-free, healthy B. suaveolens is needed. In addition, as new CDV hosts have been repeatedly reported (Pacifico et al., 2016; Salamon et al., 2015; Tomitaka et al., 2014; Verma et al., 2014), we are monitoring nationwide occurrence to prevent the spread of the virus to other crops.

The Gut Microbiome and Metabolome of Two Riparian Communities in the Amazon.

During the last decades it has become increasingly clear that the microbes that live on and in humans are critical for health. The communities they form, termed microbiomes, are involved in fundamental processes such as the maturation and constant regulation of the immune system. Additionally, they constitute a strong defense barrier to invading pathogens, and are also intricately linked to nutrition. The parameters that affect the establishment and maintenance of these microbial communities are diverse, and include the genetic background, mode of birth, nutrition, hygiene, and host lifestyle in general. Here, we describe the characterization of the gut microbiome of individuals living in the Amazon, and the comparison of these microbial communities to those found in individuals from an urban, industrialized setting. Our results showed striking differences in microbial communities from these two types of populations. Additionally, we used high-throughput metabolomics to study the chemical ecology of the gut environment and found significant metabolic changes between the two populations. Although we cannot point out a single cause for the microbial and metabolic changes observed between Amazonian and urban individuals, they are likely to include dietary differences as well as diverse patterns of environmental exposure. To our knowledge, this is the first description of gut microbial and metabolic profiles in Amazonian populations, and it provides a starting point for thorough characterizations of the impact of individual environmental conditions on the human microbiome and metabolome.

Identification of Histoplasma causing an unexplained disease cluster in Matthews Ridge, Guyana.

Here, we report the identification of Histoplasma causing an unexplained disease cluster in Matthews Ridge, Guyana. In March 2019, 14 employees of Chongqing Bosai Mining Company, China, working in a manganese mining of Guyana, had unexplained fever, and two of them died. We obtained lung and brain tissues as well as the blood samples from the two deceased cases (patient No. 1 and 2), and bronchoscopy lavages and cerebrospinal fluid samples from one severe case (patient No. 3), respectively. All samples were tested by pathological examination, high-throughput sequencing, and real-time PCR. Pathological detection showed the presence of spore-like structures in the lung tissue of patient No. 1, indicating a fungal infection in this patient. Nanopore sequencing identified the existing of H. capsulatum in the lung tissue sample within 13 h. Next-generation sequencing identified specific fragments of H. capsulatum in all of the samples tested (lung, brain and blood serum from the deceased cases, and plasma from the severe case). Real-time PCR assays did not reveal any viral infection related to transmission from bat feces. We conclude that H. capsulatum was the causative pathogen of this disease cluster based on epidemiologic, clinical, pathological and nucleic acid evidence.

Effect of pre-emulsified sesame oil on physical-chemical and rheological properties of pork batters

Abstract Physical-chemical and rheological properties of pork batters as affected by replacing pork back-fat with pre-emulsified sesame oil were investigated. Replacement of pork back-fat with pre-emulsified sesame oil, improved L* value, moisture and protein content, hardness, cohesiveness, and chewiness, declined a* value, fat content and energy, but not affect cooking yield. When used pre-emulsified sesame oil to replace pork back-fat 50%, the sample had the highest L* value and texture. According to the results of dynamic rheological, replaced pork back-fat by pre-emulsified sesame oil increased the storage modulus (G') values at 80 °C, and formed firm gel. The result of Low-field nuclear magnetic resonance (LF-NMR) shown that the batters with pre-emulsified sesame oil had higher water holding capacity than the control. Overall, the batters with pre-emulsified sesame oil enabled lowering of fat and energy contents, making the pork batter had better texture.

Repression of Salmonella Host Cell Invasion by Aromatic Small Molecules from the Human Fecal Metabolome.

The human microbiome is a collection of microorganisms that inhabit every surface of the body that is exposed to the environment, generally coexisting peacefully with their host. These microbes have important functions, such as producing vitamins, aiding in maturation of the immune system, and protecting against pathogens. We have previously shown that a small-molecule extract from the human fecal microbiome has a strong repressive effect on Salmonella enterica serovar Typhimurium host cell invasion by modulating the expression of genes involved in this process. Here, we describe the characterization of this biological activity. Using a series of purification methods, we obtained fractions with biological activity and characterized them by mass spectrometry. These experiments revealed an abundance of aromatic compounds in the bioactive fraction. Selected compounds were obtained from commercial sources and tested with respect to their ability to repress the expression of hilA, the gene encoding the master regulator of invasion genes in Salmonella We found that the aromatic compound 3,4-dimethylbenzoic acid acts as a strong inhibitor of hilA expression and of invasion of cultured host cells by Salmonella Future studies should reveal the molecular details of this phenomenon, such as the signaling cascades involved in sensing this bioactive molecule.IMPORTANCE Microbes constantly sense and adapt to their environment. Often, this is achieved through the production and sensing of small extracellular molecules. The human body is colonized by complex communities of microbes, and, given their biological and chemical diversity, these ecosystems represent a platform where the production and sensing of molecules occur. In previous work, we showed that small molecules produced by microbes from the human gut can significantly impair the virulence of the enteric pathogen Salmonella enterica Here, we describe a specific compound from the human gut that produces this same effect. The results from this work not only shed light on an important biological phenomenon occurring in our bodies but also may represent an opportunity to develop drugs that can target these small-molecule interactions to protect us from enteric infections and other diseases.

Variation of Spirulina maxima biomass production in different depths of urea-used culture medium.

Fewer studies have assessed the outdoor cultivation of Spirulina maxima compared with S. platensis, although the protein content of S. maxima is higher than S. platensis. Spirulina growth medium requires an increased amount of NaHCO3, Na2CO3, and NaNO3, which increases the production cost. Therefore, the current study used a low-cost but high-efficiency biomass production medium (Medium M-19) after testing 33 different media. The medium depth of 25 cm (group A) was sub-divided into A1 (50% cover with a black curtain (PolyMax, 12 oz ultra-blackout), A2 (25% cover), and A3 (no cover). Similarly the medium depths of 30 and 35 cm were categorized as groups B (B1, B2, and B3) and C (C1, C2, and C3), respectively, and the effects of depth and surface light availability on growth and biomass production were assessed. The highest biomass production was 2.05 g L-1 in group A2, which was significantly higher (p < 0.05) than that in all other groups and sub-groups. Spirulina maxima died in B1 and C1 on the fifth day of culture. The biochemical composition of the biomass obtained from A2 cultures, including protein, carbohydrate, lipid, moisture, and ash, was 56.59%, 14.42%, 0.94%, 5.03%, and 23.02%, respectively. Therefore, S. maxima could be grown outdoors with the highest efficiency in urea-enriched medium at a 25-cm medium depth with 25% surface cover or uncovered.

Variation of Spirulina maxima biomass production in different depths of urea-used culture medium

Fewer studies have assessed the outdoor cultivation of Spirulina maxima compared with S. platensis, although the protein content of S. maxima is higher than S. platensis. Spirulina growth medium requires an increased amount of NaHCO3, Na2CO3, and NaNO3, which increases the production cost. Therefore, the current study used a low-cost but high-efficiency biomass production medium (Medium M-19) after testing 33 different media. The medium depth of 25 cm (group A) was sub-divided into A1 (50% cover with a black curtain (PolyMax, 12 oz ultra-blackout), A2 (25% cover), and A3 (no cover). Similarly the medium depths of 30 and 35 cm were categorized as groups B (B1, B2, and B3) and C (C1, C2, and C3), respectively, and the effects of depth and surface light availability on growth and biomass production were assessed. The highest biomass production was 2.05 g L-1 in group A2, which was significantly higher (p < 0.05) than that in all other groups and sub-groups. Spirulina maxima died in B1 and C1 on the fifth day of culture. The biochemical composition of the biomass obtained from A2 cultures, including protein, carbohydrate, lipid, moisture, and ash, was 56.59%, 14.42%, 0.94%, 5.03%, and 23.02%, respectively. Therefore, S. maxima could be grown outdoors with the highest efficiency in urea-enriched medium at a 25-cm medium depth with 25% surface cover or uncovered.

Mycobacterium leprae intracellular survival relies on cholesterol accumulation in infected macrophages: a potential target for new drugs for leprosy treatment.

We recently showed that Mycobacterium leprae (ML) is able to induce lipid droplet formation in infected macrophages. We herein confirm that cholesterol (Cho) is one of the host lipid molecules that accumulate in ML-infected macrophages and investigate the effects of ML on cellular Cho metabolism responsible for its accumulation. The expression levels of LDL receptors (LDL-R, CD36, SRA-1, SR-B1, and LRP-1) and enzymes involved in Cho biosynthesis were investigated by qRT-PCR and/or Western blot and shown to be higher in lepromatous leprosy (LL) tissues when compared to borderline tuberculoid (BT) lesions. Moreover, higher levels of the active form of the sterol regulatory element-binding protein (SREBP) transcriptional factors, key regulators of the biosynthesis and uptake of cellular Cho, were found in LL skin biopsies. Functional in vitro assays confirmed the higher capacity of ML-infected macrophages to synthesize Cho and sequester exogenous LDL-Cho. Notably, Cho colocalized to ML-containing phagosomes, and Cho metabolism impairment, through either de novo synthesis inhibition by statins or depletion of exogenous Cho, decreased intracellular bacterial survival. These findings highlight the importance of metabolic integration between the host and bacteria to leprosy pathophysiology, opening new avenues for novel therapeutic strategies to leprosy.

Mycobacterium leprae intracellular survival relies on cholesterol accumulation in infected macrophages: a potential target for new drugs for leprosy treatment

We recently showed that Mycobacterium leprae (ML) is able to induce lipid droplet formation in infected macrophages. We herein confirm that cholesterol (Cho) is one of the host lipid molecules that accumulate in ML-infected macrophages and investigate the effects of ML on cellular Cho metabolism responsible for its accumulation. The expression levels of LDL receptors (LDL-R, CD36, SRA-1, SR-B1, and LRP-1) and enzymes involved in Cho biosynthesis were investigated by qRT-PCR and/or Western blot and shown to be higher in lepromatous leprosy (LL) tissues when compared to borderline tuberculoid (BT) lesions. Moreover, higher levels of the active form of the sterol regulatory element-binding protein (SREBP) transcriptional factors, key regulators of the biosynthesis and uptake of cellular Cho, were found in LL skin biopsies. Functional in vitro assays confirmed the higher capacity of ML-infected macrophages to synthesize Cho and sequester exogenous LDL-Cho. Notably, Cho colocalized to ML-containing phagosomes, and Cho metabolism impairment, through either de novo synthesis inhibition by statins or depletion of exogenous Cho, decreased intracellular bacterial survival. These findings highlight the importance of metabolic integration between the host and bacteria to leprosy pathophysiology, opening new avenues for novel therapeutic strategies to leprosy.

Metabolic signatures of triatomine vectors of Trypanosoma cruzi unveiled by metabolomics.

Chagas disease is a trypanosomiasis whose causative agent is the protozoan parasite Trypanosoma cruzi, which is transmitted to humans by hematophagous insects known as triatomines and affects a large proportion of South America. The digestive tract of the insect vectors in which T. cruzi develops constitutes a dynamic environment that affects the development of the parasite. Thus, we set out to investigate the chemical composition of the triatomine intestinal tract through a metabolomics approach. We performed Direct Infusion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry on fecal samples of three triatomine species (Rhodnius prolixus, Triatoma infestans, Panstrongylus megistus) fed with rabbit blood. We then identified groups of metabolites whose frequencies were either uniform in all species or enriched in each of them. By querying the Human Metabolome Database, we obtained putative identities of the metabolites of interest. We found that a core group of metabolites with uniform frequencies in all species represented approximately 80% of the molecules detected, whereas the other 20% varied among triatomine species. The uniform core was composed of metabolites of various categories, including fatty acids, steroids, glycerolipids, nucleotides, sugars, and others. Nevertheless, the metabolic fingerprint of triatomine feces differs depending on the species considered. The variable core was mainly composed of prenol lipids, amino acids, glycerolipids, steroids, phenols, fatty acids and derivatives, benzoic acid and derivatives, flavonoids, glycerophospholipids, benzopyrans, and quinolines. Triatomine feces constitute a rich and varied chemical medium whose constituents are likely to affect T. cruzi development and infectivity. The complexity of the fecal metabolome of triatomines suggests that it may affect triatomine vector competence for specific T. cruzi strains. Knowledge of the chemical environment of T. cruzi in its invertebrate host is likely to generate new ways to understand the factors influencing parasite proliferation as well as methods to control Chagas disease.

Metabonomics reveals drastic changes in anti-inflammatory/pro-resolving polyunsaturated fatty acids-derived lipid mediators in leprosy disease.

Despite considerable efforts over the last decades, our understanding of leprosy pathogenesis remains limited. The complex interplay between pathogens and hosts has profound effects on host metabolism. To explore the metabolic perturbations associated with leprosy, we analyzed the serum metabolome of leprosy patients. Samples collected from lepromatous and tuberculoid patients before and immediately after the conclusion of multidrug therapy (MDT) were subjected to high-throughput metabolic profiling. Our results show marked metabolic alterations during leprosy that subside at the conclusion of MDT. Pathways showing the highest modulation were related to polyunsaturated fatty acid (PUFA) metabolism, with emphasis on anti-inflammatory, pro-resolving omega-3 fatty acids. These results were confirmed by eicosanoid measurements through enzyme-linked immunoassays. Corroborating the repertoire of metabolites altered in sera, metabonomic analysis of skin specimens revealed alterations in the levels of lipids derived from lipase activity, including PUFAs, suggesting a high lipid turnover in highly-infected lesions. Our data suggest that omega-6 and omega-3, PUFA-derived, pro-resolving lipid mediators contribute to reduced tissue damage irrespectively of pathogen burden during leprosy disease. Our results demonstrate the utility of a comprehensive metabonomic approach for identifying potential contributors to disease pathology that may facilitate the development of more targeted treatments for leprosy and other inflammatory diseases.