Microbial synthesis of health-promoting inositols

D-chiro-inositol and scyllo-inositol are known for their health-promoting properties and promising as ingredients for functional foods. Strains of Bacillus subtilis and Corynebacterium glutamicum were created by metabolic engineering capable of inexpensive production of these two rare inositols from myo-inositol, which is the most common inositol in nature. In addition, further modifications have enabled the synthesis of the two rare inositols from the much-cheaper carbon sources, glucose or sucrose.

Bacillus velezensis S141, a soybean growth-promoting bacterium, hydrolyzes isoflavone glycosides into aglycones

Bacillus velezensis S141, a plant growth-promoting rhizobacteria (PGPR), was isolated from a soybean field in Thailand. Previous studies demonstrated that S141 enhanced soybean growth, stimulating nodulation for symbiotic nitrogen fixation with soybean root nodule bacteria, including Bradyrhizobium diazoefficience USDA110. Isoflavone glycosides are produced in soybean roots and hydrolyzed into their aglycones, triggering nodulation. This study revealed that S141 efficiently hydrolyzed two isoflavone glycosides in soybean roots (daidzin and genistin) to their aglycones (daidzein and genistein, respectively). However, S141, Bacillus subtilis 168, NCIB3610, and B. velezensis FZB42 hydrolyzed isoflavone glucosides into aglycones. A BLASTp search suggested that S141 and the other three strains shared four genes encoding β-glucosidases corresponding to bglA, bglC, bglH, and gmuD in B. subtilis 168. The gene inactivation analysis of B. subtilis 168 revealed that bglC encoded the major β-glucosidase, contributing about half of the total activity to hydrolyze isoflavone glycosides and that bglA, bglH, and gmuD, all barely committed to the hydrolysis of isoflavone glycosides. Thus, an unknown β-glucosidase exists, and our genetic knowledge of β-glucosidases was insufficient to evaluate the ability to hydrolyze isoflavone glycosides. Nevertheless, S141 could predominate in the soybean rhizosphere, releasing isoflavone aglycones to enhance soybean nodulation.

Genes encoding a novel thermostable bacteriocin in the thermophilic bacterium Aeribacillus pallidus PI8

AIM

Aeribacillus pallidus PI8 is a Gram-positive thermophilic bacterium that produces thermostable antimicrobial substances against several bacterial species, including Geobacillus kaustophilus HTA426. In the present study, we sought to identify genes of PI8 with antibacterial activity.

METHODS AND RESULTS

We isolated, cloned, and characterized a thermostable bacteriocin from A. pallidus PI8 and named it pallidocyclin. Mass spectrometric analyses of pallidocyclin revealed that it had a circular peptide structure, and its precursor was encoded by pcynA in the PI8 genome. pcynA is the second gene within the pcynBACDEF operon. Expression of the full-length pcynBACDEF operon in Bacillus subtilis produced intact pallidocyclin, whereas expression of pcynF in G. kaustophilus HTA426 conferred resistance to pallidocyclin.

CONCLUSION

Aeribacillus pallidus PI8 possesses the pcynBACDEF operon to produce pallidocyclin. pcynA encodes the pallidocyclin precursor, and pcynF acts as an antagonist of pallidocyclin.

Association of atmospheric temperature with out-of-hospital natural deaths occurrence before and during the COVID-19 pandemic in Osaka, Japan

In this study, we aimed to investigate the relationship between out-of-hospital natural death (OHND) and ambient temperature and examine the seriousness of the impact of the coronavirus disease-2019 (COVID-19) pandemic on this relationship. We used data from the Osaka Prefectural Office of Medical Examiners between 2018 and 2022 and performed a retrospective observational study. A Poisson regression model was applied to examine the relationship between OHND and temperature in Osaka City. The relative risk of OHND at 5 °C and 32 °C compared to the minimum mortality temperature increased from 1.81 in the pre-COVID-19 period to 2.03 in the post-COVID-19 period at 5 °C and from 1.29 in the pre-COVID-19 period to 1.60 in the post-COVID-19 period at 32 °C. The increase in relative risk per 1 °C increase from the pre- to post-COVID-19 period was 1.0551 (rate ratio [RR], p = 0.003) in the hot environment and 1.0233 (RR, p = 0.013) in the cold environment, which was larger than that in the hot environment. Although the risk of OHND increased at both temperatures, the change in OHND risk during post-COVID-19 was larger in the hot environment than in the cold environment, implicating the effect of pandemics in the current scenario of global warming.

Greedy reduction of Bacillus subtilis genome yields emergent phenotypes of high resistance to a DNA damaging agent and low evolvability

Genome-scale engineering enables rational removal of dispensable genes in chassis genomes. Deviating from this approach, we applied greedy accumulation of deletions of large dispensable regions in the Bacillus subtilis genome, yielding a library of 298 strains with genomes reduced up to 1.48 Mb in size. High-throughput physiological phenotyping of these strains confirmed that genome reduction is associated with substantial loss of cell fitness and accumulation of synthetic-sick interactions. Transcriptome analysis indicated that <15% of the genes conserved in our genome-reduced strains exhibited a twofold or higher differential expression and revealed a thiol-oxidative stress response. Most transcriptional changes can be explained by loss of known functions and by aberrant transcription at deletion boundaries. Genome-reduced strains exhibited striking new phenotypes relative to wild type, including a very high resistance (increased >300-fold) to the DNA-damaging agent mitomycin C and a very low spontaneous mutagenesis (reduced 100-fold). Adaptive laboratory evolution failed to restore cell fitness, except when coupled with a synthetic increase of the mutation rate, confirming low evolvability. Although mechanisms underlying this emergent phenotype are not understood, we propose that low evolvability can be leveraged in an engineering strategy coupling reductive cycles with evolutive cycles under induced mutagenesis.

Functional analysis of a gene cluster for putative bacteriocin deduced from the genome sequence of Aeribacillus pallidus PI8

Bacteriocins are a large family of peptides synthesized ribosomally by a variety of bacterial species. The genome of one of the thermophilic Gram-positive bacteria, Aeribacillus pallidus PI8, was found to possess an operon comprising five genes possibly involved in the production of a putative bacteriocin that was named pcnABCDE for the production of "pallidocyclicin." This study investigated the function of the pcn operon experimentally. The heterologous expression of the entire pcn operon from the plasmid was toxic to Escherichia coli but not to Bacillus subtilis. However, when the entire pcn operon was expressed constitutively, even the growth of B. subtilis was impaired, and at least pcnA was implied to serve as the precursor of pallidocyclicin. In addition, a strain of B. subtilis expressing the entire pcn operon from the plasmid showed toxicity to another thermophilic species, Geobacillus kaustophilus, at elevated temperatures, whereas another strain lacking pcnE alone from the pcn operon lost the toxicity, suggesting that pcnE might be involved in the biosynthesis of pallidocyclicin when it is produced in B. subtilis.

A New Tool for the Flexible Genetic Manipulation of Geobacillus kaustophilus

Geobacillus kaustophilus , a thermophilic Gram-positive bacterium, is an attractive host for the development of high-temperature bioprocesses. However, its reluctance against genetic manipulation by standard methodologies hampers its exploitation. Here, we describe a simple methodology in which an artificial DNA segment on the chromosome of Bacillus subtilis can be transferred via pLS20-mediated conjugation resulting in subsequent integration in the genome of G. kaustophilus. Therefore, we have developed a transformation strategy to design an artificial DNA segment on the chromosome of B. subtilis and introduce it into G. kaustophilus . The artificial DNA segment can be freely designed by taking advantage of the plasticity of the B. subtilis genome and combined with the simplicity of pLS20 conjugation transfer. This transformation strategy would adapt to various Gram-positive bacteria other than G. kaustophilus . Graphical abstract.

Gestational Intermittent Hypoxia Induces Mitochondrial Impairment in the Geniohyoid Muscle of Offspring Rats

Introduction Gestational intermittent hypoxia (IH), a hallmark of obstructive sleep apnea during gestation, alters respiratory neural control and diaphragm muscle contractile function in the offspring. The geniohyoid (GH) muscle is innervated by the respiratory-related hypoglossal nerve and plays a role in tongue traction and suckling, motor behaviors that then give way to chewing. Here, we aimed to investigate the effects of gestational exposure to IH on the muscle development and metabolism of GH and masseter muscles in male offspring rats. Materials and methods Pregnant Sprague-Dawley rats were exposed to IH (3-min periods of 4-21% O2) for eight hours/day during gestational days 7-20. The GH and masseter muscles from 35-day-old male offspring (n = 6 in each group) were analyzed.  Results Gestational IH induction reduced type IIA fiber size in the GH muscle of the offspring but not in the masseter muscle. Western blot analysis showed that gestational IH-induced significant downregulation of peroxisome proliferator-activated receptor (PPAR)-gamma coactivator 1-alpha (PGC1α) protein in the GH muscle but not in the masseter muscle. Moreover, optic atrophy 1 and mitofusin-2 proteins were decreased and mitochondrial fission 1 protein levels were increased in the GH muscle of the offspring exposed to gestational IH. Mitochondrial adenosine triphosphate (ATP) synthase subunit alpha and transcriptional factor A (TFAM) were decreased in the GH muscle post-gestational IH. Conclusion These findings suggest that gestational IH-induced impaired mitochondrial metabolism and alteration of oxidative myofibers of the GH muscle in the pre-adolescent offspring, but not the masseter muscle, owing to the susceptibility of GH muscular mitochondria to gestational IH.

A novel method for transforming Geobacillus kaustophilus with a chromosomal segment of Bacillus subtilis transferred via pLS20-dependent conjugation

Background

Geobacillus kaustophilus is a thermophilic Gram-positive bacterium. Methods for its transformation are still under development. Earlier studies have demonstrated that pLS20catΔoriT mobilized the resident mobile plasmids from Bacillus subtilis to G. kaustophilus and transferred long segments of chromosome from one cell to another between B. subtilis.

Results

In this study, we applied mobilization of the B. subtilis chromosome mediated by pLS20catΔoriT to transform G. kaustophilus. We constructed a gene cassette to be integrated into G. kaustophilus and designed it within the B. subtilis chromosome. The pLS20catΔoriT-mediated conjugation successfully transferred the gene cassette from the B. subtilis chromosome into the G. kaustophilus allowing for the desired genetic transformation.

Conclusions

This transformation approach described here will provide a new tool to facilitate the flexible genetic manipulation of G. kaustophilus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01759-8.

Intermittent hypoxia retards mandibular growth and alters RANKL expression in adolescent and juvenile rats

OBJECTIVES

Chronic intermittent hypoxia (IH), a common state experienced in obstructive sleep apnoea (OSA), retards mandibular growth in adolescent rats. The aim of this study was to elucidate the differential effects of IH on mandibular growth in different growth stages.

MATERIALS AND METHODS

Three-week-old (juvenile stage) and 7-week-old (adolescent stage) male Sprague-Dawley rats underwent IH for 3 weeks. Age-matched control rats were exposed to room air. Mandibular growth was evaluated by radiograph analysis, micro-computed tomography, real-time polymerase chain reaction and immunohistology. Tibial growth was evaluated as an index of systemic skeletal growth.

RESULTS

IH had no significant impact on the general growth of either the juvenile or adolescent rats. However, it significantly decreased the total mandibular length and the posterior corpus length of the mandible in the adolescent rats and the anterior corpus length in the juvenile rats. IH also increased bone mineral density (BMD) of the condylar head in adolescent rats but did not affect the BMD of the tibia. Immunohistological analysis showed that the expression level of receptor activation of nuclear factor-κB ligand significantly decreased (in contrast to its messenger ribonucleicacid level) in the condylar head of adolescent rats with IH, while the number of osteoprotegerin-positive cells was comparable in the mandibles of adolescent IH rats and control rats.

LIMITATIONS

The animal model could not simulate the pathological conditions of OSA completely and there were differences in bone growth between humans and rodents.

CONCLUSIONS

These results suggest that the susceptibility of mandibular growth retardation to IH depends on the growth stage of the rats.

Genome sequences of two strains of Lactococcus lactis subsp. cremoris with the same ancestry but a different capacity to produce exopolysaccharides

Strains of Lactococcus lactis subsp. cremoris are used to produce yogurt containing exopolysaccharides with a sticky texture. When strain G3-2 producing exopolysaccharides was grown at elevated temperatures, a spontaneous mutant EPSC, which had lost exopolysaccharides biosynthesis, was isolated. Genomes of the two strains were determined to be composed of a 2.4-Mb chromosome and up to eleven plasmids, and it was revealed that one of the plasmids encoding the gene cluster for exopolysaccharides biosynthesis was lost selectively in EPSC.

Skeletal EWSR1-NFATC2 sarcoma previously diagnosed as Ewing-like adamantinoma: A case report and literature review emphasizing its unique radiological features

Ewing-like adamantinoma (EAD) is a rare bone tumor. It remains unclear whether EAD belongs to adamantinoma, Ewing sarcoma (ES), or an independent category. Herein, we present a case of femoral sarcoma previously diagnosed as EAD in a 26-year-old woman. We observed amplified EWSR1 and NFATC2 fusion signals using fluorescence in situ hybridization. Prompted by its unique radiological features, we reviewed the current literature on skeletal EWSR1-NFATC2 sarcoma (ENS) and EAD. In addition to the similar histological features, we found that both ENS and EAD displayed similar characteristic radiological features, such as the tendency to occur in the diaphysis of long bones, cortical expansion and buttressing-type thickening, and bone surface involvement with saucer-like erosion without cortical destruction. We believe that these unique radiological features were related to its indolent behavior. Altogether, it is possible that previously reported EAD cases may be neither ES nor the classic adamantinoma but ENS. Further studies are needed to clarify the relationship between EAD and ENS.

Selective β2-Adrenoceptor Blockade Rescues Mandibular Growth Retardation in Adolescent Rats Exposed to Chronic Intermittent Hypoxia

Activation of the sympathoadrenal system is associated with sleep apnea-related symptoms and metabolic dysfunction induced by chronic intermittent hypoxia (IH). IH can induce hormonal imbalances and growth retardation of the craniofacial bones. However, the relationship between IH and β2-adrenergic receptor signaling in the context of skeletal growth regulation is unclear. This study aimed to investigate the role of β2-adrenergic receptors in IH-induced mandibular growth retardation and bone metabolic alterations. Male 7-week-old Sprague–Dawley rats were subjected to IH for 3 weeks. IH conditions were established using original customized hypoxic chambers; IH was induced at a rate of 20 cycles per hour (oxygen levels changed from 4 to 21% in one cycle) for 8 h per day during the 12 h “lights on” period. The rats received intraperitoneal administration of a β2-adrenergic antagonist (butoxamine) or saline. To exclude dietary effects on general growth, the normoxic rats with saline, normoxic rats with butoxamine, and IH rats with butoxamine were subjected to food restriction to match the body weight gains between IH and other three groups. Body weight, heart rate, blood pressure, and plasma concentrations of leptin, serotonin, and growth hormone were measured. Bone growth and metabolism were evaluated using radiography, microcomputed tomography, and immunohistochemical staining. Plasma leptin levels were significantly increased, whereas that of serotonin and growth hormone were significantly decreased following IH exposure. Leptin levels recovered following butoxamine administration. Butoxamine rescued IH-induced mandibular growth retardation, with alterations in bone mineral density at the condylar head of the mandible. Immunohistochemical analysis revealed significantly lower expression levels of receptor activator of nuclear factor-kappa B ligand (RANKL) in the condylar head of IH-exposed rats. Conversely, recovery of RANKL expression was observed in IH-exposed rats administered with butoxamine. Collectively, our findings suggest that the activation of β2-adrenergic receptors and leptin signaling during growth may be involved in IH-induced skeletal growth retardation of the mandible, which may be mediated by concomitant changes in RANKL expression at the growing condyle.

Intermittent hypoxia inhibits mandibular cartilage growth with reduced TGF-β and SOX9 expressions in neonatal rats

Intermittent hypoxia (IH) has been associated with skeletal growth. However, the influence of IH on cartilage growth and metabolism is unknown. We compared the effects of IH on chondrocyte proliferation and maturation in the mandibular condyle fibrocartilage and tibial hyaline cartilage of 1-week-old male Sprague-Dawley rats. The rats were exposed to normoxic air (n = 9) or IH at 20 cycles/h (nadir, 4% O₂; peak, 21% O₂; 0% CO₂) (n = 9) for 8 h each day. IH impeded body weight gain, but not tibial elongation. IH also increased cancellous bone mineral and volumetric bone mineral densities in the mandibular condylar head. The mandibular condylar became thinner, but the tibial cartilage did not. IH reduced maturative and increased hypertrophic chondrocytic layers of the middle and posterior mandibular cartilage. PCR showed that IH shifted proliferation and maturation in mandibular condyle fibrocartilage toward hypertrophic differentiation and ossification by downregulating TGF-β and SOX9, and upregulating collagen X. These effects were absent in the tibial growth plate hyaline cartilage. Our results showed that neonatal rats exposed to IH displayed underdeveloped mandibular ramus/condyles, while suppression of chondrogenesis marker expression was detected in the growth-restricted condylar cartilage.

Identification of a repressor for the two iol operons required for inositol catabolism in Geobacillus kaustophilus

Geobacillus kaustophilus HTA426, a thermophilic Gram-positive bacterium, feeds on inositol as its sole carbon source, and an iol gene cluster required for inositol catabolism has been postulated with reference to the iol genes in Bacillus subtilis. The iol gene cluster of G. kaustophilus comprises two tandem operons induced in the presence of inositol; however, the mechanism underlying this induction remains unclear. B. subtilis iolQ is known to be involved in the regulation of iolX encoding scyllo-inositol dehydrogenase, and its homologue in HTA426 was found two genes upstream of the first gene (gk1899) of the iol gene cluster and was termed iolQ in G. kaustophilus. When iolQ was inactivated in G. kaustophilus, not only cellular myo-inositol dehydrogenase activity due to gk1899 expression but also the transcription of the two iol operons became constitutive. IolQ was produced and purified as a C-terminal histidine (His)-tagged fusion protein in Escherichia coli and subjected to an in vitro gel electrophoresis mobility shift assay to examine its DNA-binding property. It was observed that IolQ bound to the DNA fragments containing each of the two iol promoter regions and that DNA binding was antagonized by myo-inositol. Moreover, DNase I footprinting analyses identified two tandem binding sites of IolQ within each of the iol promoter regions. By comparing the sequences of the binding sites, a consensus sequence for IolQ binding was deduced to form a palindrome of 5'-RGWAAGCGCTTSCY-3' (where R=A or G, W=A or T, S=G or C, and Y=C or T). IolQ functions as a transcriptional repressor regulating the induction of the two iol operons responding to myo-inositol.

Intermittent hypoxia induces turbinate mucosal hypertrophy via upregulating the gene expression related to inflammation and EMT in rats

PURPOSE

Chronic intermittent hypoxia (IH) plays a pivotal role in the consequences of obstructive sleep apnea (OSA). It has been demonstrated that IH impairs nasomaxillary complex growth to reduce nasal airway cavity size in rodent models. Although turbinate dysfunction with inflammatory mucosal hypertrophy is related to OSA, the role of IH in turbinate hypertrophy with inflammation-driven fibrosis is unknown. Here, we aimed to clarify the pathogenesis of inflammatory mucosal hypertrophy and epithelial-mesenchymal transition (EMT) in the nasal turbinate under IH.

METHODS

Seven-week-old male Sprague-Dawley rats were exposed to IH (4% O₂ to 21% O₂ with 0% CO₂) at a rate of 20 cycles/h.

RESULTS

Hypertrophy of the turbinate mucosa occurred after 3 weeks, with the turbinate mucosa of the experimental group becoming significantly thicker than in the control group. Immunostaining showed that IH increased the expression of TGFβ and N-cadherin and decreased E-cadherin expression in the turbinate mucosa. Quantitative PCR analysis demonstrated that IH enhanced the expression of not only the inflammatory markers Tnf-a, Il-1b, and Nos2 but also the EMT markers Tgf-b1, Col1a1, and Postn.

CONCLUSIONS

Collectively, these results suggest that IH induced turbinate hypertrophy via upregulation of gene expression related to inflammation and EMT in the nasal mucosa.

Production of scyllo-Inositol: Conversion of Rice Bran into a Promising Disease-Modifying Therapeutic Agent for Alzheimer's Disease

scyllo-Inositol (SI) is one of the inositol stereoisomers, rare in the nature, and expected as a promising disease-modifying therapeutic agent for Alzheimer's disease. On the other hand, myo-inositol (MI) is another inositol stereoisomer most abundant in nature and thus supplied from agricultural byproducts including rice bran. Bacillus subtilis was genetically modified in its inositol metabolism and phytase secretion, to develope the bioconversion processes to produce SI from rice bran. Phytase, an enzyme that degrades phytate in rice bran into MI, was secreted in a B. subtilis strain with the optimized signal peptide. Another B. subtilis strain was constructed with the constitutive and simultaneous overexpression of IolG and IolW, which are the two inositol dehydrogenases responsible for the conversion, to demonstrate an efficient conversion of MI into SI with a rate up to 10 g/L/48 h. In order to devise further elevation in the conversion efficiency, we attempted to improve the substrate uptake by overexpressing iolT for the major MI transporter. In addition, Escherichia coli pntAB encoding the membrane-bound transhydrogenase was introduced aiming at enhanced supply of NADPH required for the rate-limiting IolW reaction. These additional modifications successfully elevated the conversion efficiency with an improved rate up to almost 30 g/L/48 h. Together with the improved phytase secretion, technological infrastructure for social implementation of SI production from rice bran is on the way.

A bacterial cell factory converting glucose into scyllo-inositol, a therapeutic agent for Alzheimer's disease

A rare stereoisomer of inositol, scyllo-inositol, is a therapeutic agent that has shown potential efficacy in preventing Alzheimer’s disease. Mycobacterium tuberculosis ino1 encoding myo-inositol-1-phosphate (MI1P) synthase (MI1PS) was introduced into Bacillus subtilis to convert glucose-6-phosphate (G6P) into MI1P. We found that inactivation of pbuE elevated intracellular concentrations of NAD⁺·NADH as an essential cofactor of MI1PS and was required to activate MI1PS. MI1P thus produced was dephosphorylated into myo-inositol by an intrinsic inositol monophosphatase, YktC, which was subsequently isomerized into scyllo-inositol via a previously established artificial pathway involving two inositol dehydrogenases, IolG and IolW. In addition, both glcP and glcK were overexpressed to feed more G6P and accelerate scyllo-inositol production. Consequently, a B. subtilis cell factory was demonstrated to produce 2 g L⁻¹scyllo-inositol from 20 g L⁻¹ glucose. This cell factory provides an inexpensive way to produce scyllo-inositol, which will help us to challenge the growing problem of Alzheimer’s disease in our aging society.

Michon et al. describe the use of a recombinant Bacillus subtilis as a cell factory capable of producing scyllo-inositol, a therapeutic compound for Alzheimer’s disease, from inexpensive glucose. They demonstrate that it could produce 2 g L⁻¹ of scyllo-inositol from 20 g L⁻¹ glucose.

Absence of H3F3A mutation in a subset of malignant giant cell tumor of bone

Giant cell tumor of bone typically involves the epiphysis of the long bones of skeletally mature patients. It is genetically characterized by highly recurrent and specific mutations of the H3F3A gene, which encodes histone H3.3. The most common mutation H3F3A G34W can readily be detected by a recently developed mutation-specific antibody. Giant cell tumor of bone rarely transforms to a sarcoma (malignant giant cell tumor of bone), which has not been genetically characterized in detail. We studied seven clinicopathologically defined malignant giant cell tumors, as well as two H3F3A-mutant bone sarcomas without giant cell tumor histology using a combination of clinicopathological, immunohistochemical, and molecular methods (Sanger sequencing + pyrosequencing or next generation sequencing). The cases included five men and four women, with a median age at initial diagnosis of 27 years. The two H3F3A G34W-positive sarcomas without giant cell tumor histology involved the subarticular epiphyseal sites, suggesting relatedness with giant cell tumor of bone. In two of the seven clinicopathologically defined malignant giant cell tumor cases, the sarcoma tissue showed the H3F3A G34W mutation. However, in the remaining five cases, in contrast to their associated H3F3A G34W-mutant giant cell tumor, the sarcoma lacked the H3F3A G34W mutation, either entirely or sub-clonally in the samples tested. This discordant mutation status was confirmed in all instances by immunohistochemistry and sequencing. A FISH analysis suggested that the absence of the H3F3A G34W mutation may be related to deletion of the H3F3A gene. Therefore, we have demonstrated that H3F3A G34W mutation, a critical driver in giant cell tumor, is absent in a subset of malignant giant cell tumor of bone. This novel recurrent phenomenon has potential biological and diagnostic implications, and further study is required to better characterize this progression pathway and understand its mechanism.

Estrogen replacement enhances insulin-induced AS160 activation and improves insulin sensitivity in ovariectomized rats

Menopause predisposes women to impaired glucose metabolism, but the role of estrogen remains unclear. In this study, we examined the effects of chronic estrogen replacement on whole body insulin sensitivity and insulin signaling in ovariectomized rats. Female Wistar rats aged 9 wk were ovariectomized under anesthesia. After 4 wk, pellets containing either 17β-estradiol (E₂) or placebo (Pla) were subcutaneously implanted in the rats. After 4 wk of treatment, the intra-abdominal fat accumulation was greater in the Pla group than that in the E₂ group. Hyperinsulinemic-euglycemic clamp analysis and intravenous glucose tolerance test revealed that insulin sensitivity was significantly lower in the Pla group than in the E₂ group. In addition, Western blotting showed that in vivo insulin stimulation increased protein kinase B (Akt) phosphorylation to a similar degree in the gastrocnemius and liver of both groups, but phosphorylated Akt2 Ser⁴⁷⁴ was enhanced in the muscle of the E₂ group compared with the Pla group. Moreover, insulin-stimulated phosphorylation of Akt substrate of 160 kDa (AS160) Thr⁶⁴² was observed only in the E₂ group, resulting in the difference between the two groups. Additionally, AS160 protein and mRNA levels were higher in muscle of the E₂ group than the Pla group. In contrast, E₂ replacement had no effect on glucose transporter 4 protein levels in muscle and glycogen synthase kinase-3β in muscle and liver. These results suggest that estrogen replacement improves insulin sensitivity by activating the Akt2/AS160 pathway in the insulin-stimulated muscle of ovariectomized rats.

Evaluation of Inhibitory Activities of UK-2A, an Antimycin-Type Antibiotic, and Its Synthetic Analogues against the Production of Anti-inflammatory Cytokine IL-4

The inhibitory activities of the antimycin-class antibiotics UK-2A, antimycin A, and splenocin B against the production of anti-inflammatory cytokine IL-4, which is related to IgE-mediated allergic responses in rat basophilic leukemia (RBL-2H3) cells, were evaluated. Although antimycin A and splenocin B showed cytotoxicity at concentrations at which IL-4 release from the cells was restricted, UK-2A was found to restrict IL-4 release without cytotoxicity. Three UK-2A analogues (4-6) were then synthesized and assessed. Compound 5 restricted IL-4 release dose-dependently without cytotoxicity, and its effect was more potent than that of UK-2A.

Irradiation by ultraviolet light-emitting diodes inactivates influenza a viruses by inhibiting replication and transcription of viral RNA in host cells

Influenza A viruses (IAVs) pose a serious global threat to humans and their livestock, especially poultry and pigs. This study aimed to investigate how to inactivate IAVs by using different ultraviolet-light-emitting diodes (UV-LEDs). We developed sterilization equipment with light-emitting diodes (LEDs) those peak wavelengths were 365 nm (UVA-LED), 310 nm (UVB-LED), and 280 nm (UVC-LED). These UV-LED irradiations decreased dose fluence-dependent plaque-forming units of IAV H1N1 subtype (A/Puerto Rico/8/1934) infected Madin-Darby canine kidney (MDCK) cells, but the inactivation efficiency of UVA-LED was significantly lower than UVB- and UVC-LED. UV-LED irradiations did not alter hemagglutination titer, but decreased accumulation of intracellular total viral RNA in infected MDCK cells was observed. Additionally, UV-LED irradiations suppressed the accumulation of intracellular mRNA (messenger RNA), vRNA (viral RNA), and cRNA (complementary RNA), as measured by strand-specific RT-PCR. These results suggest that UV-LEDs inhibit host cell replication and transcription of viral RNA. Both UVB- and UVC-LED irradiation decreased focus-forming unit (FFU) of H5N1 subtype (A/Crow/Kyoto/53/2004), a highly pathogenic avian IAV (HPAI), in infected MDCK cells, and the amount of FFU were lower than the H1N1 subtype. From these results, it appears that IAVs may have different sensitivity among the subtypes, and UVB- and UVC-LED may be suitable for HPAI virus inactivation.

Bradyrhizobium diazoefficiens USDA110 PhaR functions for pleiotropic regulation of cellular processes besides PHB accumulation

Background

Bradyrhizobium diazoefficiens USDA110 nodulates soybeans for nitrogen fixation. It accumulates poly-3-hydroxybutyrate (PHB), which is of physiological importance as a carbon/energy source for survival during starvation, infection, and nitrogen fixation conditions. PHB accumulation is orchestrated by not only the enzymes for PHB synthesis but also PHB-binding phasin proteins (PhaPs) stabilizing the PHB granules. The transcription factor PhaR controls the phaP genes.

Results

Inactivation of phaR led to decreases in PHB accumulation, less cell yield, increases in exopolysaccharide (EPS) production, some improvement in heat stress tolerance, and slightly better growth under microaerobic conditions. Changes in the transcriptome upon phaR inactivation were analyzed. PhaR appeared to be involved in the repression of various target genes, including some PHB-degrading enzymes and others involved in EPS production. Furthermore, in vitro gel shift analysis demonstrated that PhaR bound to the promoter regions of representative targets. For the phaP1 and phaP4 promoter regions, PhaR-binding sites were determined by DNase I footprinting, allowing us to deduce a consensus sequence for PhaR-binding as TGCRNYGCASMA (R: A or G, Y: C or T, S: C or G, M: A or C). We searched for additional genes associated with a PhaR-binding sequence and found that some genes involved in central carbon metabolism, such as pdhA for pyruvate dehydrogenase and pckA for phosphoenolpyruvate carboxykinase, may be regulated positively and directly by PhaR.

Conclusions

These results suggest that PhaR could regulate various genes not only negatively but also positively to coordinate metabolism holistically in response to PHB accumulation.

Electronic supplementary material

The online version of this article (10.1186/s12866-018-1317-2) contains supplementary material, which is available to authorized users.

A rare case of ectopic papillary thyroid carcinoma transformed into squamous cell carcinoma

A rare case of a metastatic ectopic papillary thyroid carcinoma (PTC) of the lung that transformed into a squamous cell carcinoma (SCC) that resembles pulmonary SCC is reported. A subcutaneous ectopic PTC in the left anterior neck area, together with a normal thyroid gland, were excised. The ectopic PTC showed thyroglobulin, TTF-1 and PAX-8 immunoreactivity and a BRAF V600E mutation. During the post-operative follow-up period, a rapidly growing 2 cm nodular lesion in the lower left lobe of the lung was detected. The lung tumor consisted of solid sheets and nests of squamous cells but without the nuclear features of PTC. Neither papillary nor follicular structures of cancer cells were identified. Carcinoma cells were positive for TTF-1, PAX-8, p40, CK14, and p63, while showing a high Ki-67 labeling index and a BRAF V600E mutation. These results support our interpretation of a PTC that originated from ectopic thyroid tissue in the left anterior neck and that developed a lung metastasis showing squamous cell differentiation.

Intermittent hypoxia causes mandibular growth retardation and macroglossia in growing rats

INTRODUCTION

In this study, we aimed to examine the role of intermittent hypoxia (IH) in dentofacial morphologic changes in growing rats.

METHODS

Seven-week-old male rats were exposed to IH at 20 cycles per hour (nadir of 4% oxygen to peak of 21% oxygen) for 8 hours per day for 6 weeks. Control rats were exposed to normoxia (N). Maxillofacial growth was compared between the 2 groups by linear measurements on cephalometric radiographs. To examine the dental arch morphology, study models and microcomputed tomography images of the jaws were taken. Additionally, tongue size was measured.

RESULTS

The gonial angle and the ramus of the mandible were smaller in the IH group than in the N group, whereas the body weights were not different between the 2 groups. Morphometric analysis of the dentition showed a significantly wider mandibular dentition and narrower maxillary dentition in the IH than in the N group. The relative width (+4.2 %) and length (tongue apex to vallate papillae, +3.5 %) of the tongue to the mandible were significantly greater in the IH group than in the N group.

CONCLUSIONS

IH induced dentofacial morphologic discrepancies in growing rats.

Characterization and mutation analysis of a halotolerant serine protease from a new isolate of Bacillus subtilis

OBJECTIVES

A bacterial halotolerant enzyme was characterized to understand the molecular mechanism of salt adaptation and to explore its protein engineering potential.

RESULTS

Halotolerant serine protease (Apr_No16) from a newly isolated Bacillus subtilis strain no. 16 was characterized. Multiple alignments with previously reported non-halotolerant proteases, including subtilisin Carlsberg, indicated that Apr_No16 has eight acidic or polar amino acid residues that are replaced by nonpolar amino acids in non-halotolerant proteases. Those residues were hypothesized to be one of the primary contributors to salt adaptation. An eightfold mutant substituted with Ala residues exhibited 1.2- and 1.8-fold greater halotolerance at 12.5% (w/v) NaCl than Apr_No16 and Carlsberg, respectively. Amino acid substitution notably shifted the theoretical pI of the eightfold mutant, from 6.33 to 9.23, compared with Apr_No16. The resulting protein better tolerated high salt conditions.

CONCLUSIONS

Changing the pI of a bacterial serine protease may be an effective strategy to improve the enzyme's halotolerance.

Bacillus subtilis IolQ (DegA) is a transcriptional repressor of iolX encoding NAD+-dependent scyllo-inositol dehydrogenase

Background

Bacillus subtilis is able to utilize at least three inositol stereoisomers as carbon sources, myo-, scyllo-, and D-chiro-inositol (MI, SI, and DCI, respectively). NAD⁺-dependent SI dehydrogenase responsible for SI catabolism is encoded by iolX. Even in the absence of functional iolX, the presence of SI or MI in the growth medium was found to induce the transcription of iolX through an unknown mechanism.

Results

Immediately upstream of iolX, there is an operon that encodes two genes, yisR and iolQ (formerly known as degA), each of which could encode a transcriptional regulator. Here we performed an inactivation analysis of yisR and iolQ and found that iolQ encodes a repressor of the iolX transcription. The coding sequence of iolQ was expressed in Escherichia coli and the gene product was purified as a His-tagged fusion protein, which bound to two sites within the iolX promoter region in vitro.

Conclusions

IolQ is a transcriptional repressor of iolX. Genetic evidences allowed us to speculate that SI and MI might possibly be the intracellular inducers, however they failed to antagonize DNA binding of IolQ in in vitro experiments.

A rare case of poorly differentiated thyroid carcinoma probably arising from a nodular goiter

Background

Some poorly differentiated thyroid carcinomas (PDTC) arise from pre-existing, well-differentiated carcinomas of follicular cell origin; however, others most likely arise de novo. The case of a PDTC adjacent to a pre-existing nodular goiter is very rare.

Case presentation

A patient had a PDTC, a widely invasive, cellular tumor with cells that lacked the nuclear features of a papillary thyroid carcinoma. Carcinoma cells were arranged in trabecular, solid, and microfollicular histological patterns and displayed high mitotic activity. A nodule partially encapsulated in a thick fibrous capsule was found adjacent to the PDTC. The nodule was composed of small or dilated follicles, without papillary carcinoma-like nuclear features, that were consistent with a nodular goiter. The PDTC showed a high Ki-67 labeling index and an NRAS gene mutation (codon 61, Q61K).

Conclusion

These results support our diagnosis of a PDTC, probably arising from a nodular goiter.

A new-generation of Bacillus subtilis cell factory for further elevated scyllo-inositol production

BACKGROUND

A stereoisomer of inositol, scyllo-inositol (SI), has been regarded as a promising therapeutic agent for Alzheimer's disease. However, this compound is relatively rare, whereas another stereoisomer of inositol, myo-inositol (MI) is abundant in nature. Bacillus subtilis 168 has the ability to metabolize inositol stereoisomers, including MI and SI. Previously, we reported a B. subtilis cell factory with modified inositol metabolism that converts MI into SI in the culture medium. The strain was constructed by deleting all genes related to inositol metabolism and overexpressing key enzymes, IolG and IolW. By using this strain, 10 g/l of MI initially included in the medium was completely converted into SI within 48 h of cultivation in a rich medium containing 2% (w/v) Bacto soytone.

RESULTS

When the initial concentration of MI was increased to 50 g/l, conversion was limited to 15.1 g/l of SI. Therefore, overexpression systems of IolT and PntAB, the main transporter of MI in B. subtilis and the membrane-integral nicotinamide nucleotide transhydrogenase in Escherichia coli respectively, were additionally introduced into the B. subtilis cell factory, but the conversion efficiency hardly improved. We systematically determined the amount of Bacto soytone necessary for ultimate conversion, which was 4% (w/v). As a result, the conversion of SI reached to 27.6 g/l within 48 h of cultivation.

CONCLUSIONS

The B. subtilis cell factory was improved to yield a SI production rate of 27.6 g/l/48 h by simultaneous overexpression of IolT and PntAB, and by addition of 4% (w/v) Bacto soytone in the conversion medium. The concentration of SI was increased even in the stationary phase perhaps due to nutrients in the Bacto soytone that contribute to the conversion process. Thus, MI conversion to SI may be further optimized via identification and control of these unknown nutrients.

The use of human samples obtained during medicolegal autopsies in research: An introduction to current conditions and initiatives in Japan

Background Leftover samples obtained during autopsies are extremely important basic materials for forensic research. However, there are no established practices for research-related use of obtained samples. Objective This study discusses good practice for the secondary use of samples collected during medicolegal autopsies. Methods A questionnaire was posted to all 76 departments of forensic medicine performing medicolegal autopsies in Japan, and 48 responses were received (response rate: 63.2%). As a secondary analysis, we surveyed information provided on department websites. Results Ethical reviews conducted when samples were to be used for research varied greatly among departments, with 21 (43.8%) departments reporting 'fundamentally, all cases are subject to review', eight (16.7%) reporting 'only some are subject to review' and 17 (39.6%) reporting 'none are subject to review'. Information made available on websites indicated that 11 departments had a statement of some type to bereaved families about the potential research use of human samples obtained during autopsies. Nine of these included a notice stating that bereaved families may revoke their consent for use. Several departments used an opt-out system. Conclusion There is no common practice in the field of legal medicine on the ethical use for medical research of leftover samples from medicolegal autopsies. The trust of not only bereaved families but also society in general is required for the scientific validity and social benefits of medical studies using leftover samples from medicolegal autopsies through the use of opt-out consenting and offline and online dissemination and public-relations activities.

Bacillus subtilis iolU encodes an additional NADP+-dependent scyllo-inositol dehydrogenase

Bacillus subtilis genes iolG, iolW, iolX, ntdC, yfiI, yrbE, yteT, and yulF belong to the Gfo/Idh/MocA family. The functions of iolG, iolW, iolX, and ntdC are known; however, the functions of the others are unknown. We previously reported the B. subtilis cell factory simultaneously overexpressing iolG and iolW to achieve bioconversion of myo-inositol (MI) into scyllo-inositol (SI). YulF shares a significant similarity with IolW, the NADP⁺-dependent SI dehydrogenase. Transcriptional abundance of yulF did not correlate to that of iol genes involved in inositol metabolism. However, when yulF was overexpressed instead of iolW in the B. subtilis cell factory, SI was produced from MI, suggesting a similar function to iolW. In addition, we demonstrated that recombinant His₆-tagged YulF converted scyllo-inosose into SI in an NADPH-dependent manner. We have thus identified yulF encoding an additional NADP⁺-dependent SI dehydrogenase, which we propose to rename iolU.

Heterologous expression and characterisation of the Aspergillus aspartic protease involved in the hydrolysis and decolorisation of red-pigmented proteins

BACKGROUND

Aspergillus repens strain MK82 produces an aspartic protease (PepA_MK82) that efficiently decolorises red-pigmented proteins during dried bonito fermentation. However, further expansion of the industrial applications of PepA_MK82 requires the high-level production and efficient preparation of the recombinant enzyme.

RESULTS

The genomic DNA and cDNA fragments encoding the protease were cloned from strain MK82 and sequenced. Phylogenetic analysis of PepA_MK82 and comparisons with previously reported fungal aspartic proteases showed that PepA_MK 82 clusters with different groups of these enzymes. Heterologous expression of PepA_MK82 in Pichia pastoris yielded preparations of higher purity than obtained with an Escherichia coli expression system. Total protease activity in a 100-mL culture of the P. pastoris transformant was 14 times higher than that from an equivalent culture of A. repense MK82. The recombinant PepA_MK82 was easily obtained via acetone precipitation; the final recovery was 83%. PepA_MK82 and its recombinant had similar characteristics in terms of their optimal pH, thermostability, and decolorisation activity. The recombinant was also able to decolorise flaked, dried bonito and to bleach a blood-stained cloth.

CONCLUSION

Given its ability to hydrolyse and decolorise red-pigmented proteins, recombinant PepA_MK8 can be exploited in the food industry and as a stain-removal agent in laundry applications. © 2016 Society of Chemical Industry.

Bacillus subtilis 5'-nucleotidases with various functions and substrate specificities

BACKGROUND

In Escherichia coli, nagD, yrfG, yjjG, yieH, yigL, surE, and yfbR encode 5'-nucleotidases that hydrolyze the phosphate group of 5'-nucleotides. In Bacillus subtilis, genes encoding 5'-nucleotidase have remained to be identified.

RESULTS

We found that B. subtilis ycsE, araL, yutF, ysaA, and yqeG show suggestive similarities to nagD. Here, we expressed them in E. coli to purify the respective His₆-tagged proteins. YcsE exhibited significant 5'-nucleotidase activity with a broader specificity, whereas the other four enzymes had rather weak but suggestive activities with various capacities and substrate specificities. In contrast, B. subtilis yktC shares high similarity with E. coli suhB encoding an inositol monophosphatase. YktC exhibited inositol monophosphatase activity as well as 5'-nucleotidase activity preferential for GMP and IMP. The ycsE, yktC, and yqeG genes are induced by oxidative stress and were dispensable, although yqeG was required to maintain normal growth on solid medium. In the presence of diamide, only mutants lacking yktC exhibited enhanced growth defects, whereas the other mutants without ycsE or yqeG did not.

CONCLUSIONS

Accordingly, in B. subtilis, at least YcsE and YktC acted as major 5'-nucleotidases and the four minor enzymes might function when the intracellular concentrations of substrates are sufficiently high. In addition, YktC is involved in resistance to oxidative stress caused by diamide, while YqeG is necessary for normal colony formation on solid medium.

Intermittent Hypoxia Influences Alveolar Bone Proper Microstructure via Hypoxia-Inducible Factor and VEGF Expression in Periodontal Ligaments of Growing Rats

Intermittent hypoxia (IH) recapitulates morphological changes in the maxillofacial bones in children with obstructive sleep apnea (OSA). Recently, we found that IH increased bone mineral density (BMD) in the inter-radicular alveolar bone (reflecting enhanced osteogenesis) in the mandibular first molar (M1) region in the growing rats, but the underlying mechanism remains unknown. In this study, we focused on the hypoxia-inducible factor (HIF) pathway to assess the effect of IH by testing the null hypothesis of no significant differences in the mRNA-expression levels of relevant factors associated with the HIF pathway, between control rats and growing rats with IH. To test the null hypothesis, we investigated how IH enhances mandibular osteogenesis in the alveolar bone proper with respect to HIF-1α and vascular endothelial growth factor (VEGF) in periodontal ligament (PDL) tissues. Seven-week-old male Sprague-Dawley rats were exposed to IH for 3 weeks. The microstructure and BMD in the alveolar bone proper of the distal root of the mandibular M1 were evaluated using micro-computed tomography (micro-CT). Expression of HIF-1α and VEGF mRNA in PDL tissues were measured, whereas osteogenesis was evaluated by measuring mRNA levels for alkaline phosphatase (ALP) and bone morphogenetic protein-2 (BMP-2). The null hypothesis was rejected: we found an increase in the expression of all of these markers after IH exposure. The results provided the first indication that IH enhanced osteogenesis of the mandibular M1 region in association with PDL angiogenesis during growth via HIF-1α in an animal model.

Lethal ventricular tachycardia triggered after femoral fracture repair in an obese man with insulin-resistant diabetes

An obese man (height, 178 cm; weight, 160 kg; body mass index, 50.5 kg/m²) with a history of recurrent ventricular tachycardia (VT), cardiomyopathy, coronary sclerosis, and insulin-resistant diabetes suffered a right femur fracture in a vehicular accident. His fracture was repaired the following day, but shortly after surgery, his serum potassium (K⁺) level increased, presumably due to K⁺ leakage from the injured muscles, leading to persistent VT and death. An autopsy revealed severe cardiac hypertrophy, moderate coronary sclerosis, and histological findings of myocardial hypercontraction, but not myoglobin-related renal failure, pulmonary thrombosis, lipid emboli, or inflammation. The hyperkalemia was not corrected by glucose-insulin infusion and led to the death of the patient due to the preexisting cardiomyopathy, coronary sclerosis, and a predisposition to VT. In addition to the autopsy, the analysis of the clinical course was indispensable for determining the cause of death as hyperkalemia-related VT.

Intermittent hypoxia upregulates hepatic heme oxygenase-1 and ferritin-1, thereby limiting hepatic pathogenesis in rats fed a high-fat diet

Non-alcoholic fatty liver disease (NAFLD) is prevalent in patients with sleep apnea syndrome (SAS). Intermittent hypoxia (IH) and a high-fat diet (HFD) reproduce SAS and NAFLD, respectively, in rodents. In this study, rats were fed either an HFD or a standard diet (SD) for 2 weeks, and breathed either IH air or normoxic air for 4 days (early phase) or 6 weeks (late phase), with the same diets maintained during the exposure. HFD increased hepatic lipid accumulation, as detected by oil-red staining and triglyceride content. However, IH exposure reversed the hepatic steatosis at the late phase in these HFD-rats. IH exposure also increased hepatic expression of HO-1 and iron-binding protein ferritin-1 at the late phase, in association with increase in serum iron, bilirubin, and hepatic levels of lipid peroxides, such as 4-hydroxy-2-nonenal (HNE). IH exposure increased serum levels of hemoglobin (Hb) at the early phase and immunofluorescence of Hb and HO-1 in CD68-positive Kupffer cells (KCs) at the late phase. These findings support that IH induces erythrocytosis, erythro-phagocytosis, and generation of Hb in the KCs. The Hb promotes HO-1 expression in KCs, thereby produces iron, bilirubin, and carbon monoxide (CO). The iron would be either sequestrated by ferritin-1, transferred to the bone marrow for erythropoiesis, or would produce hydroxyradicals and HNE in the liver of rats fed an HFD. HNE might also contribute to the upregulation of HO-1, transferrin-1, and IκB, thereby limiting hepatic steatosis and inflammation via inhibition of nuclear factor κB (NFκB) activation.

Mitochondrial m-calpain opens the mitochondrial permeability transition pore in ischemia-reperfusion

BACKGROUND/OBJECTIVES

Opening of the mitochondrial permeability transition pore (mPTP) is involved in ischemia-reperfusion injury. Isoforms of Ca(2+)-activated cysteine proteases, calpains, are implicated in the development of myocardial infarction in ischemia-reperfusion. Growing evidence has revealed the presence of calpains in the mitochondria. We aimed to characterize mitochondrial calpains in the rat heart and to investigate the roles of calpains in mPTP opening after ischemia-reperfusion.

METHODS AND RESULTS

Western blotting analysis showed the expression of μ-calpain, m-calpain and calpain 10 in mitochondria isolated from male Sprague-Dawley rats, but casein zymography detected only m-calpain activity. Subcellular fractionation of mitochondria demonstrated the distribution of m-calpain to the matrix fraction. Addition of >500μM of Ca(2+) to isolated mitochondria induced mitochondrial swelling, reflecting mPTP opening, and calpain activation. Ca(2+)-induced mitochondrial swelling was inhibited partially by the calpain inhibitor calpeptin. These results support a partial contribution of calpain in the opening of the mPTP. The addition of Ca(2+) to the mitochondria induced inactivation of complex I of the electron transport chain, and cleavage of the ND6 complex I subunit, which were inhibited by calpeptin. Mitochondria isolated from rat hearts that underwent 30min of coronary occlusion followed by 30min of reperfusion showed activation of mitochondrial calpains, ND6 cleavage, complex I inactivation, and mPTP opening, which were inhibited by pretreatment with calpain inhibitor 1.

CONCLUSIONS

We demonstrated for the first time the presence of mitochondrial matrix m-calpain, and its contribution to complex I inactivation and mPTP opening after postischemic reperfusion in the rat heart.

Multiple hepatic sclerosing hemangioma mimicking metastatic liver tumor successfully treated by laparoscopic surgery: Report of a case

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Sclerosing hemangioma should be included among the differential diagnoses of multiple liver tumors in patients with colorectal cancer.

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Laparoscopic hepatectomy is useful for diagnostic therapy for undiagnosed multiple liver tumors.

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This report is the first to describe multiple hepatic sclerosing hemangiomas treated by laparoscopic surgery.

Introduction

Hepatic sclerosing hemangioma is a very rare benign tumor, characterized by fibrosis and hyalinization occurring in association with degeneration of a hepatic cavernous hemangioma. We report here a rare case of multiple hepatic sclerosing hemangioma mimicking metastatic liver tumor that was successfully treated using laparoscopic surgery.

Presentation of case

A 67-year-old woman with multiple liver tumors underwent single-incision laparoscopic sigmoidectomy under a diagnosis of advanced sigmoid cancer with multiple liver metastases. Examination of surgical specimens of sigmoid colon revealed moderately differentiated adenocarcinoma invading the serosa, and no lymph node metastases. Serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9 remained within normal limits throughout the course. Two months after sigmoidectomy, the patient underwent laparoscopic partial hepatectomy of S1 and S6 of the liver and cholecystectomy. Histopathological examination showed that the tumors mainly comprised hyalinized tissue and collagen fibers with sporadic vascular spaces on hematoxylin and eosin-stained sections, yielding a diagnosis of multiple hepatic sclerosing hemangioma. No evidence of recurrence has been seen as of 21 months postoperatively.

Discussion

Differentiating multiple sclerosing hemangiomas from metastatic liver tumors was quite difficult because the radiological findings were closely compatible with liver metastases. Laroscopic hepatectomy provided less blood loss, a shorter duration of hospitalization, and good cosmetic results.

Conclusion

Sclerosing hemangioma should be included among the differential diagnoses of multiple liver tumors in patients with colorectal cancer. Laparoscopic hepatectomy is useful for diagnostic therapy for undiagnosed multiple liver tumors.

Immunohistochemical study of the autophagy marker microtubule-associated protein 1 light chain 3 in normal and steatotic human livers

AIM

Autophagy has been implicated in lipid droplet (LD) turnover. Adipose differentiation-related protein (ADRP) and microtubule-associated protein 1 light chain 3 (LC3) monitor LD and autophagosomes, respectively. We examined whether immunohistochemical staining of ADRP and LC3 can monitor LD and autophagy, and if so, whether autophagy is related to LD turnover in post-mortem human livers.

METHODS

We performed conventional immunohistochemistry of LC3 in paraffin-embedded human livers with different severities of steatosis, obtained at autopsy. Double immunofluorescence microscopy using anti-LC3 and anti-ADRP antibodies was performed to elucidate the relationship between autophagy and LD turnover.

RESULTS

LC3 immunohistochemistry reproducibly delineated puncta in normal human livers, which were preferentially located around the central venal zone. The extent of LC3 immunostaining reduced with progressing steatosis. Double immunofluorescence for ADRP and LC3 demonstrated an inverse relationship between ADRP positive areas and LC3 positive areas, as well as the co-localization of ADRP and LC3 on a part of small LD but not large LD.

CONCLUSION

These findings suggest that impaired autophagy promotes steatosis and that autophagy may be implicated in LD turnover.

Influence of injection beam emittance on beam transmission efficiency in a cyclotron

The JAEA AVF cyclotron accelerates various kinds of high-energy ion beams for research in biotechnology and materials science. Beam intensities of an ion species of the order of 10(-9)-10(-6) ampere are often required for various experiments performed sequentially over a day. To provide ion beams with sufficient intensity and stability, an operator has to retune an ion source in a short time. However, the beam intensity downstream of the cyclotron rarely increases in proportion to the intensity at the ion source. To understand the cause of this beam behavior, transmission efficiencies of a (12)C(5+) beam from an electron cyclotron resonance ion source to the cyclotron were measured for various conditions of the ion source. Moreover, a feasible region for acceleration in the emittance of the injection beam was clarified using a transverse-acceptance measuring system. We confirmed that the beam emittance and profile were changed depending on the condition of the ion source and that matching between the beam emittance and the acceptance of the cyclotron was degraded. However, after fine-tuning to improve the matching, beam intensity downstream of the cyclotron increased.