Cellular senescence in white matter microglia is induced during ageing in mice and exacerbates the neuroinflammatory phenotype.

Cellular senescence, a state of irreversible cell-cycle arrest caused by a variety of cellular stresses, is critically involved in age-related tissue dysfunction in various organs. However, the features of cells in the central nervous system that undergo senescence and their role in neural impairment are not well understood as yet. Here, through comprehensive investigations utilising single-cell transcriptome analysis and various mouse models, we show that microglia, particularly in the white matter, undergo cellular senescence in the brain and spinal cord during ageing and in disease models involving demyelination. Microglial senescence is predominantly detected in disease-associated microglia, which appear in ageing and neurodegenerative diseases. We also find that commensal bacteria promote the accumulation of senescent microglia and disease-associated microglia during ageing. Furthermore, knockout of p16INK4a, a key senescence inducer, ameliorates the neuroinflammatory phenotype in damaged spinal cords in mice. These results advance our understanding of the role of cellular senescence in the central nervous system and open up possibilities for the treatment of age-related neural disorders.

Bacterial induction of B cell senescence promotes age-related changes in the gut microbiota.

The elucidation of the mechanisms of ageing and the identification of methods to control it have long been anticipated. Recently, two factors associated with ageing-the accumulation of senescent cells and the change in the composition of gut microbiota-have been shown to play key roles in ageing. However, little is known about how these phenomena occur and are related during ageing. Here we show that the persistent presence of commensal bacteria gradually induces cellular senescence in gut germinal centre B cells. Importantly, this reduces both the production and diversity of immunoglobulin A (IgA) antibodies that target gut bacteria, thereby changing the composition of gut microbiota in aged mice. These results have revealed the existence of IgA-mediated crosstalk between the gut microbiota and cellular senescence and thus extend our understanding of the mechanism of gut microbiota changes with age, opening up possibilities for their control.

IGH cytogenetic abnormalities can be detected in multiple myeloma by imaging flow cytometry.

AIMS: Cytogenetic abnormalities involving the IGH gene are seen in up to 55% of patients with multiple myeloma. Current testing is performed manually by fluorescence in situ hybridisation (FISH) on purified plasma cells. We aimed to assess whether an automated imaging flow cytometric method that uses immunophenotypic cell identification, and does not require cell isolation, can identify IGH abnormalities. METHODS: Aspirated bone marrow from 10 patients with multiple myeloma were studied. Plasma cells were identified by CD38 and CD138 coexpression and assessed with FISH probes for numerical or structural abnormalities of IGH. Thousands of cells were acquired on an imaging flow cytometer and numerical data and digital images were analysed. RESULTS: Up to 30 000 cells were acquired and IGH chromosomal abnormalities were detected in 5 of the 10 marrow samples. FISH signal patterns seen included fused IGH signals for IGH/FGFR3 and IGH/MYEOV, indicating t(4;14) and t(11;14), respectively. In addition, three IGH signals were identified, indicating trisomy 14 or translocation with an alternate chromosome. The lowest limit of detection of an IGH abnormality was in 0.05% of all cells. CONCLUSIONS: This automated high-throughput immuno-flowFISH method was able to identify translocations and trisomy involving the IGH gene in plasma cells in multiple myeloma. Thousands of cells were analysed and without prior cell isolation. The inclusion of positive plasma cell identification based on immunophenotype led to a lowest detection level of 0.05% marrow cells. This imaging flow cytometric FISH method offers the prospect of increased precision of detection of critical genetic lesions involving IGH and other chromosomal defects in multiple myeloma.

Distinct responsiveness to rifaximin in patients with hepatic encephalopathy depends on functional gut microbial species.

Hepatic encephalopathy (HE) is the neuropsychiatric complication of liver cirrhosis (LC). The influence of gut microbiota on HE pathogenesis has been suggested but not precisely elucidated. Here, we investigate how the gut microbial profile changed in patients with HE to clarify the functional gut microbial species associated with HE. We focused on their responses to rifaximin (RFX), a nonabsorbable antibiotic used in HE therapy. Feces samples were collected from patients with decompensated LC (all HE), patients with compensated LC, and healthy controls, and fecal gut microbial profiles were compared using 16S ribosomal RNA gene amplicon and metagenomic sequencing. The linear discriminant analysis effect size was used to identify specific species. Urease-positive Streptococcus salivarius, which can produce ammonia, was identified as the most significantly abundant gut microbiota in the HE group, and its ability to elevate the levels of blood ammonia as well as brain glutamine was experimentally verified in mice. Urease-negative Ruminococcus gnavus was also identified as a significantly abundant species in patients with RFX-nonresponsive HE after RFX administration. Interestingly, R. gnavus enhanced urease activity of recombinant urease itself, implying that R. gnavus could amplify ammonia production of surrounding urease-positive microbiota. Furthermore, the sensitivity of S. salivarius and R. gnavus to RFX depended on conjugated secondary bile acid levels, suggesting a therapeutic potential of the combined use of secondary bile acid levels with RFX for enhancing the efficacy of RFX. This study identified specific gut bacterial species abundant in patients with HE and verified their functions linked to HE pathophysiology. Targeting these bacteria could be a potentially effective strategy to treat HE.

Development and evaluation of a colorectal cancer screening method using machine learning-based gut microbiota analysis.

Accumulating evidence indicates that alterations of gut microbiota are associated with colorectal cancer (CRC). Therefore, the use of gut microbiota for the diagnosis of CRC has received attention. Recently, several studies have been conducted to detect the differences in the gut microbiota between healthy individuals and CRC patients using machine learning-based gut bacterial DNA meta-sequencing analysis, and to use this information for the development of CRC diagnostic model. However, to date, most studies had small sample sizes and/or only cross-validated using the training dataset that was used to create the diagnostic model, rather than validated using an independent test dataset. Since machine learning-based diagnostic models cause overfitting if the sample size is small and/or an independent test dataset is not used for validation, the reliability of these diagnostic models needs to be interpreted with caution. To circumvent these problems, here we have established a new machine learning-based CRC diagnostic model using the gut microbiota as an indicator. Validation using independent test datasets showed that the true positive rate of our CRC diagnostic model increased substantially as CRC progressed from Stage I to more than 60% for CRC patients more advanced than Stage II when the false positive rate was set around 8%. Moreover, there was no statistically significant difference in the true positive rate between samples collected in different cities or in any part of the colorectum. These results reveal the possibility of the practical application of gut microbiota-based CRC screening tests.

SARS-CoV-2 infection triggers paracrine senescence and leads to a sustained senescence-associated inflammatory response.

Reports of post-acute COVID-19 syndrome, in which the inflammatory response persists even after SARS-CoV-2 has disappeared, are increasing1, but the underlying mechanisms of post-acute COVID-19 syndrome remain unknown. Here, we show that SARS-CoV-2-infected cells trigger senescence-like cell-cycle arrest2,3 in neighboring uninfected cells in a paracrine manner via virus-induced cytokine production. In cultured human cells or bronchial organoids, these SASR-CoV-2 infection-induced senescent cells express high levels of a series of inflammatory factors known as senescence-associated secretory phenotypes (SASPs)4 in a sustained manner, even after SARS-CoV-2 is no longer detectable. We also show that the expression of the senescence marker CDKN2A (refs. 5,6) and various SASP factor4 genes is increased in the pulmonary cells of patients with severe post-acute COVID-19 syndrome. Furthermore, we find that mice exposed to a mouse-adapted strain of SARS-CoV-2 exhibit prolonged signs of cellular senescence and SASP in the lung at 14 days after infection when the virus was undetectable, which could be substantially reduced by the administration of senolytic drugs7. The sustained infection-induced paracrine senescence described here may be involved in the long-term inflammation caused by SARS-CoV-2 infection.

In silico-labeled ghost cytometry.

Characterization and isolation of a large population of cells are indispensable procedures in biological sciences. Flow cytometry is one of the standards that offers a method to characterize and isolate cells at high throughput. When performing flow cytometry, cells are molecularly stained with fluorescent labels to adopt biomolecular specificity which is essential for characterizing cells. However, molecular staining is costly and its chemical toxicity can cause side effects to the cells which becomes a critical issue when the cells are used downstream as medical products or for further analysis. Here, we introduce a high-throughput stain-free flow cytometry called in silico-labeled ghost cytometry which characterizes and sorts cells using machine-predicted labels. Instead of detecting molecular stains, we use machine learning to derive the molecular labels from compressive data obtained with diffractive and scattering imaging methods. By directly using the compressive 'imaging' data, our system can accurately assign the designated label to each cell in real time and perform sorting based on this judgment. With this method, we were able to distinguish different cell states, cell types derived from human induced pluripotent stem (iPS) cells, and subtypes of peripheral white blood cells using only stain-free modalities. Our method will find applications in cell manufacturing for regenerative medicine as well as in cell-based medical diagnostic assays in which fluorescence labeling of the cells is undesirable.

Gut bacteria identified in colorectal cancer patients promote tumourigenesis via butyrate secretion.

Emerging evidence is revealing that alterations in gut microbiota are associated with colorectal cancer (CRC). However, very little is currently known about whether and how gut microbiota alterations are causally associated with CRC development. Here we show that 12 faecal bacterial taxa are enriched in CRC patients in two independent cohort studies. Among them, 2 Porphyromonas species are capable of inducing cellular senescence, an oncogenic stress response, through the secretion of the bacterial metabolite, butyrate. Notably, the invasion of these bacteria is observed in the CRC tissues, coinciding with the elevation of butyrate levels and signs of senescence-associated inflammatory phenotypes. Moreover, although the administration of these bacteria into ApcΔ14/+ mice accelerate the onset of colorectal tumours, this is not the case when bacterial butyrate-synthesis genes are disrupted. These results suggest a causal relationship between Porphyromonas species overgrowth and colorectal tumourigenesis which may be due to butyrate-induced senescence.

Colorectal Cancer Patients Have Four Specific Bacterial Species in Oral and Gut Microbiota in Common-A Metagenomic Comparison with Healthy Subjects.

Oral microbiota is reportedly associated with gut microbiota and influences colorectal cancer (CRC) progression; however, the details remain unclear. This study aimed to evaluate the role of oral microbiota in CRC progression. Fifty-two patients with CRC and 51 healthy controls were included. Saliva and stool samples were collected, and microbiota were evaluated using 16S rRNA analysis and next-generation sequencing. Comparative analysis was performed on both groups. Linear discriminant analysis effect size (LEfSe) revealed the presence of indigenous oral bacteria, such as Peptostreptococcus, Streptococcus, and Solobacterium spp., at a significantly higher relative abundance in saliva and stool samples of CRC patients compared with controls. Next, CRC patients were divided into early stage (Stage I, II; n = 26; 50%) and advanced stage (Stage III, IV; n = 26; 50%) disease. LEfSe revealed that S. moorei was present at a significantly higher relative abundance in the advanced-stage group compared with the early-stage group, again consistent for both saliva and stool samples. Among bacterial species with significantly higher relative abundance in CRC patients, P. stomatis, S. anginosus, S. koreensis, and S. moorei originated from the oral cavity, suggesting indigenous oral bacteria may have promoted initiation of CRC carcinogenesis. Furthermore, S. moorei may influence CRC progression.

Extraperitoneal colostomy in robotic surgery for rectal cancer using a tip-up fenestrated grasper.

INTRODUCTION: Although extraperitoneal colostomy could reduce the risk for parastomal hernia formation, it is often technically demanding to dissect the extraperitoneal route laparoscopically. Here, we demonstrate our original surgical technique for extraperitoneal tunneling using a robotic instrument. MATERIALS AND SURGICAL TECHNIQUE: After total mesorectal excision (TME) and before specimen retrieval, the edge of the outer leaf of the parietal peritoneum was elevated by the grasper in the left hand and the tip-up fenestrated grasper (Tip-Up) in the right hand. The extraperitoneal tissue was opened using the scissor forceps (right hand). Then, extraperitoneal tunneling (inner tunnel) was performed using a Tip-Up with a width of approximately 4 cm that could reach adjacent to the lateral border of the abdominal rectus muscle. A round incision was made at a preoperatively marked site on the skin. The anterior rectal sheath was cut in a cruciate fashion. The abdominal rectus muscle was split, and then the posterior rectus sheath was cut longitudinally not just below the stoma marking site but also at a slant on the lateral side. The peritoneum was dissected with care to avoid opening the peritoneum. The outer side of the tunnel was broken through to the inner tunnel using an easy blunt dissection with two fingers. Kelly forceps were introduced through the extraperitoneal tunnel along with the fingers, and the stump of the sigmoid colon was grasped and exteriorized through this tunnel. DISCUSSION: Robotic retroperitoneal tunneling using a Tip-Up is easy and useful for preventing parastomal hernia.

Fluoroalkanesulfinate Salts as Dual Fluoroalkyl and SO2 Sources: Atom-Economical Fluoroalkyl-Sulfonylation of Alkenes and Alkynes by Photoredox Catalysis.

We disclose that fluoroalkanesulfinate salts ((RFSO2)nM) such as the Langlois reagent, CF3SO2Na, serve as dual fluoroalkyl (RF) and sulfur dioxide (SO2) sources by the action of photoredox catalysis. An operationally simple strategy for the vicinal installation of RF and SO2 groups onto unsaturated carbon-carbon bonds, i.e., fluoroalkyl-sulfonylation, has been developed. In particular, the present photocatalytic trifluoromethyl-sulfonylation can be applied to aromatic alkynes in addition to aliphatic and aromatic alkenes bearing various functional groups.

Airway bacteria of the recipient but not the donor are relevant to post-lung transplant pneumonia.

BACKGROUND: Optimal management of early airway infection is essential for the survival of lung transplant (LTx) recipients during the first 12 months after transplantation. This study aimed to explore the main cause of post-lung transplant pneumonia (PLTP) within 30 days after LTx. METHODS: Forty LTx patients were retrospectively analyzed. Sputum sampling from donors' and recipients' airways was performed pretransplant and posttransplant daily for the first 30 days after LTx. Organisms in the recipient's and donor's original airways were compared to pathogens responsible for PLTP. Patients with and without PLTP were also compared to identify relevant risk factors. RESULTS: Seventeen (42.5%) patients developed pneumonia (PLTP group) and 23 had no episode of pneumonia (Non-PLTP group) during the first 30 days. In the PLTP group, median time from LTx to PLTP onset was 6 days. A significantly higher incidence of PLTP was caused by recipient's rather than donor's original airway bacteria (62% vs 13%, p < 0.01). Smoking history of the donor and pretransplant airway bacterial colonization of the recipient were independent risk factors of PLTP which was associated with prolonged posttransplant mechanical ventilation with longer intensive care unit stay and worse survival outcomes. CONCLUSIONS: The recipient's original airway microflora rather than the donor's, was highly associated with PLTP. A combination of donor smoking history and recipient airway infection should be avoided, while evidence of donor lung infection is not a contraindication for LTx.

Visualization of bronchial circulation at bronchial anastomotic site using bronchial fluorescein angiography technique.

OBJECTIVES: Successful bronchial healing after a bronchoplastic procedure mainly depends on bronchial circulation at the anastomostic site. We developed a bronchial fluorescein angiography (B-FAG) technique for visualizing circulation on the bronchial surface. The technique was evaluated in animals. METHODS: Fluorescein was used as a contrast agent and an autofluorescence imaging (AFI) bronchoscope as a detector. The left main pulmonary artery (PA) and main bronchus of 10 pigs were isolated. After transection of the left main bronchus and bronchial arteries and re-anastomosis of the bronchus, the pigs were randomly divided into two groups: the PA- group (n = 5), in which the pulmonary artery was transected; and the PA+ group (n = 5), in which the pulmonary artery was preserved. Following intravenous injection of fluorescein, the distal anastomotic site was observed for 30 min with autofluorescence imaging bronchoscopy. Bronchial specimens sampled 2 days after the surgical intervention were histologically evaluated. RESULTS: In the PA- group, there was no fluorescein enhancement in the distal bronchus throughout the observation time. However, enhancement, which turned the bronchial surface from magenta to bright green, was clearly observed in less than 207 ± 102.5 s in the PA+ group. The enhancement status detected by bronchial fluorescein angiography was related to the extent of tissue damage, as was proven histologically in the acute healing stage. CONCLUSIONS: Bronchial fluorescein angiography clearly visualized the circulatory status promptly after the anastomosis procedure at the central bronchus. This technique is a potentially practical approach to predict ischaemic airway complications following bronchial anastomosis.

Use of Extended-Criteria Lungs on a Lobe-by-Lobe Basis Through Ex Vivo Lung Perfusion Assessment.

Initially rejected and extended-criteria lungs were partially used through an ex vivo lung perfusion (EVLP) assessment that was first clinically applied in Asia. The truly injured lobe (left lower lobe) was identified during 89-minute normothermic EVLP and was excised, and the remaining lobes were successfully transplanted into a patient with lymphangioleiomyomatosis. The lung lobes showed heterogeneous changes on the ex vivo rig, and a brief duration of EVLP helped differentiate lung quality on a lobe-by-lobe basis.

Establishment of transgenic lines for jumpstarter method using a composite transposon vector in the ladybird beetle, Harmonia axyridis.

In this post-genomic era, genome-wide functional analysis is indispensable. The recent development of RNA interference techniques has enabled researchers to easily analyze gene function even in non-model organisms. On the other hand, little progress has been made in the identification and functional analyses of cis-regulatory elements in non-model organisms. In order to develop experimental platform for identification and analyses of cis-regulatory elements in a non-model organism, in this case, the ladybird beetle, Harmonia axyridis, we established transgenic transposon-tagged lines using a novel composite vector. This vector enables the generation of two types of insertion products (jumpstarter and mutator). The jumpstarter portion carries a transposase gene, while the mutator segment carries a reporter gene for detecting enhancers. The full-composite element is flanked by functional termini (required for movement); however, the mutator region has an extra terminus making it possible for the mutator to remobilize on its own, thus leaving an immobile jumpstarter element behind. Each insertion type is stable on its own, but once crossed, jumpstarters can remobilize mutators. After crossing a jumpstarter and mutator line, all tested G2 females gave rise to at least one new insertion line in the next generation. This jumping rate is equivalent to the P-element-mediated jumpstarter method in Drosophila. These established transgenic lines will offer us the ideal experimental materials for the effective screening and identification of enhancers in this species. In addition, this jumpstarter method has the potential to be as effective in other non-model insect species and thus applicable to any organism.

Adult mesenchymal hamartoma of the chest wall: report of a case.

We present an adult case of the chest wall tumor, which was accidentally pointed out by a medical checkup. Surgical resection was performed for the tumor, as preoperative biopsy of the tumor suggested the possibility of malignancy. Postoperative pathological examination revealed the diagnosis of mesenchymal hamartoma of the chest wall, which usually occurs in early infancy and childhood. Immunohistochemical staining for Sox9 was positive for chondrocytes and partially positive for spindle tumor cells. It is considered that the present case was not pointed out until the patient became an adult, because the tumor was relatively small and thus asymptomatic.

Accumulation of arginine-rich cell-penetrating peptides in tumors and the potential for anticancer drug delivery in vivo.

We investigated the biodistribution of arginine-rich cell-penetrating peptides (CPPs) in tumor-xenografted nude mice after intravenous injection of fluorescently labeled CPPs using in vivo imaging. The CPPs used included HIV-1 Tat (48-60), penetratin, and the L- and D-enantiomers of oligoarginines (8, 12, and 16 residues), all of which are reported to have high cell penetration. Among the tested peptides, high accumulation in tumors was observed for the D-form of octaarginine (r8), and glycosaminoglycans played a key role. Injection of an r8-doxorubicin conjugate (4mg doxorubicin/kg) effectively suppressed tumor proliferation, with no significant decrease in mouse weight, whereas administration of doxorubicin itself (6mg/kg), yielding a similar degree of tumor-growth suppression, resulted in significant weight loss. These results suggest the potential of r8 as a prototypic tumor-targeting vector.

[Feasibility and anti-tumor activity of postoperative adjuvant chemotherapy with gemcitabine for resected pancreatic cancer].

The feasibility and anti-tumor activity of gemcitabine (GEM) as postoperative adjuvant chemotherapy were evaluated retrospectively. Between September 1998 and June 2007, patients with resected invasive pancreatic cancer (stage III, IVa, IVb) were given adjuvant chemotherapy with GEM (GEM group, n=10) or did not receive chemotherapy (n=11). Started the administration of GEM 38.5 days after surgery, and the mean duration was 15.4 months. Grade 3 or 4 adverse event was not observed in the GEM group. There was a significant difference in overall survival between the GEM group and the no-chemotherapy group (p=0.037), but there was no significant difference in disease-free survival between the two groups. Adjuvant chemotherapy with GEM was feasible and showed a benefit in patients with invasive pancreatic cancer.

Monte Carlo simulation of pressure-induced phase transitions in spin-crossover materials.

Pressure-induced phase transitions of spin-crossover materials are studied in a microscopic model taking into account the elastic interaction among distortions of lattice due to the difference of the molecular sizes between the high-spin state and the low-spin state. We perform Monte Carlo simulations in the constant pressure ensemble and reproduce several important properties of the pressure effect in a unified way with a microscopic mechanism for the first time. The simulation newly reveals how the temperature dependence of the ordering process changes with the pressure.