ETS1 governs pathological tissue-remodeling programs in disease-associated fibroblasts.

Fibroblasts, the most abundant structural cells, exert homeostatic functions but also drive disease pathogenesis. Single-cell technologies have illuminated the shared characteristics of pathogenic fibroblasts in multiple diseases including autoimmune arthritis, cancer and inflammatory colitis. However, the molecular mechanisms underlying the disease-associated fibroblast phenotypes remain largely unclear. Here, we identify ETS1 as the key transcription factor governing the pathological tissue-remodeling programs in fibroblasts. In arthritis, ETS1 drives polarization toward tissue-destructive fibroblasts by orchestrating hitherto undescribed regulatory elements of the osteoclast differentiation factor receptor activator of nuclear factor-κB ligand (RANKL) as well as matrix metalloproteinases. Fibroblast-specific ETS1 deletion resulted in ameliorated bone and cartilage damage under arthritic conditions without affecting the inflammation level. Cross-tissue fibroblast single-cell data analyses and genetic loss-of-function experiments lent support to the notion that ETS1 defines the perturbation-specific fibroblasts shared among various disease settings. These findings provide a mechanistic basis for pathogenic fibroblast polarization and have important therapeutic implications.

Expression of the readthrough transcript CiDRE in alveolar macrophages boosts SARS-CoV-2 susceptibility and promotes COVID-19 severity.

Lung infection during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via the angiotensin-I-converting enzyme 2 (ACE2) receptor induces a cytokine storm. However, the precise mechanisms involved in severe COVID-19 pneumonia are unknown. Here, we showed that interleukin-10 (IL-10) induced the expression of ACE2 in normal alveolar macrophages, causing them to become vectors for SARS-CoV-2. The inhibition of this system in hamster models attenuated SARS-CoV-2 pathogenicity. Genome-wide association and quantitative trait locus analyses identified a IFNAR2-IL10RB readthrough transcript, COVID-19 infectivity-enhancing dual receptor (CiDRE), which was highly expressed in patients harboring COVID-19 risk variants at the IFNAR2 locus. We showed that CiDRE exerted synergistic effects via the IL-10-ACE2 axis in alveolar macrophages and functioned as a decoy receptor for type I interferons. Collectively, our data show that high IL-10 and CiDRE expression are potential risk factors for severe COVID-19. Thus, IL-10R and CiDRE inhibitors might be useful COVID-19 therapies.

Dysregulated Expression of the Nuclear Exosome Targeting Complex Component Rbm7 in Nonhematopoietic Cells Licenses the Development of Fibrosis.

Fibrosis is an incurable disorder of unknown etiology. Segregated-nucleus-containing atypical monocytes (SatMs) are critical for the development of fibrosis. Here we examined the mechanisms that recruit SatMs to pre-fibrotic areas. A screen based on cytokine expression in the fibrotic lung revealed that the chemokine Cxcl12, which is produced by apoptotic nonhematopoietic cells, was essential for SatM recruitment. Analyses of lung tissues at fibrosis onset showed increased expression of Rbm7, a component of the nuclear exosome targeting complex. Rbm7 deletion suppressed bleomycin-induced fibrosis and at a cellular level, suppressed apoptosis of nonhematopoietic cells. Mechanistically, Rbm7 bound to noncoding (nc)RNAs that form subnuclear bodies, including Neat1 speckles. Dysregulated expression of Rbm7 resulted in the nuclear degradation of Neat1 speckles, the dispersion of the DNA repair protein BRCA1, and the triggering of apoptosis. Thus, Rbm7 in epithelial cells plays a critical role in the development of fibrosis by regulating ncRNA decay and thereby the production of chemokines that recruit SatMs.

Malt1-induced cleavage of regnase-1 in CD4(+) helper T cells regulates immune activation.

Regnase-1 (also known as Zc3h12a and MCPIP1) is an RNase that destabilizes a set of mRNAs, including Il6 and Il12b, through cleavage of their 3' UTRs. Although Regnase-1 inactivation leads to development of an autoimmune disease characterized by T cell activation and hyperimmunoglobulinemia in mice, the mechanism of Regnase-1-mediated immune regulation has remained unclear. We show that Regnase-1 is essential for preventing aberrant effector CD4(+) T cell generation cell autonomously. Moreover, in T cells, Regnase-1 regulates the mRNAs of a set of genes, including c-Rel, Ox40, and Il2, through cleavage of their 3' UTRs. Interestingly, T cell receptor (TCR) stimulation leads to cleavage of Regnase-1 at R111 by Malt1/paracaspase, freeing T cells from Regnase-1-mediated suppression. Furthermore, Malt1 protease activity is critical for controlling the mRNA stability of T cell effector genes. Collectively, these results indicate that dynamic control of Regnase-1 expression in T cells is critical for controlling T cell activation.

TDAG51 promotes transcription factor FoxO1 activity during LPS-induced inflammatory responses.

Tight regulation of Toll-like receptor (TLR)-mediated inflammatory responses is important for innate immunity. Here, we show that T-cell death-associated gene 51 (TDAG51/PHLDA1) is a novel regulator of the transcription factor FoxO1, regulating inflammatory mediator production in the lipopolysaccharide (LPS)-induced inflammatory response. TDAG51 induction by LPS stimulation was mediated by the TLR2/4 signaling pathway in bone marrow-derived macrophages (BMMs). LPS-induced inflammatory mediator production was significantly decreased in TDAG51-deficient BMMs. In TDAG51-deficient mice, LPS- or pathogenic Escherichia coli infection-induced lethal shock was reduced by decreasing serum proinflammatory cytokine levels. The recruitment of 14-3-3ζ to FoxO1 was competitively inhibited by the TDAG51-FoxO1 interaction, leading to blockade of FoxO1 cytoplasmic translocation and thereby strengthening FoxO1 nuclear accumulation. TDAG51/FoxO1 double-deficient BMMs showed significantly reduced inflammatory mediator production compared with TDAG51- or FoxO1-deficient BMMs. TDAG51/FoxO1 double deficiency protected mice against LPS- or pathogenic E. coli infection-induced lethal shock by weakening the systemic inflammatory response. Thus, these results indicate that TDAG51 acts as a regulator of the transcription factor FoxO1, leading to strengthened FoxO1 activity in the LPS-induced inflammatory response.

Apple-shaped obesity: A risky soil for cytokine-accelerated severity in COVID-19.

Obesity has been recognized as one of the most significant risk factors for the deterioration and mortality associated with COVID-19, but the significance of obesity itself differs among ethnicity. Multifactored analysis of our single institute-based retrospective cohort revealed that high visceral adipose tissue (VAT) burden, but not other obesity-associated markers, was related to accelerated inflammatory responses and the mortality of Japanese COVID-19 patients. To elucidate the mechanisms how VAT-dominant obesity induces severe inflammation after severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection, we infected two different strains of obese mice, C57BL/6JHamSlc-ob/ob (ob/ob), C57BLKS/J-db/db (db/db), genetically impaired in the leptin ligand and receptor, respectively, and control C57BL/6 mice with mouse-adapted SARS-CoV-2. Here, we revealed that VAT-dominant ob/ob mice were extremely more vulnerable to SARS-CoV-2 due to excessive inflammatory responses when compared to SAT-dominant db/db mice. In fact, SARS-CoV-2 genome and proteins were more abundant in the lungs of ob/ob mice, engulfed in macrophages, resulting in increased cytokine production including interleukin (IL)-6. Both an anti-IL-6 receptor antibody treatment and the prevention of obesity by leptin replenishment improved the survival of SARS-CoV-2-infected ob/ob mice by reducing the viral protein burden and excessive immune responses. Our results have proposed unique insights and clues on how obesity increases the risk of cytokine storm and death in patients with COVID-19. Moreover, earlier administration of antiinflammatory therapeutics including anti-IL-6R antibody to VAT-dominant patients might improve clinical outcome and stratification of the treatment for COVID-19, at least in Japanese patients.

Trim41 is required to regulate chromosome axis protein dynamics and meiosis in male mice.

Meiosis is a hallmark event in germ cell development that accompanies sequential events executed by numerous molecules. Therefore, characterization of these factors is one of the best strategies to clarify the mechanism of meiosis. Here, we report tripartite motif-containing 41 (TRIM41), a ubiquitin ligase E3, as an essential factor for proper meiotic progression and fertility in male mice. Trim41 knockout (KO) spermatocytes exhibited synaptonemal complex protein 3 (SYCP3) overloading, especially on the X chromosome. Furthermore, mutant mice lacking the RING domain of TRIM41, required for the ubiquitin ligase E3 activity, phenocopied Trim41 KO mice. We then examined the behavior of mutant TRIM41 (ΔRING-TRIM41) and found that ΔRING-TRIM41 accumulated on the chromosome axes with overloaded SYCP3. This result suggested that TRIM41 exerts its function on the chromosome axes. Our study revealed that Trim41 is essential for preventing SYCP3 overloading, suggesting a TRIM41-mediated mechanism for regulating chromosome axis protein dynamics during male meiotic progression.

Role of the NLRP1 inflammasome in skin cancer and inflammatory skin diseases.

Inflammasomes are cytoplasmic protein complexes that play a crucial role in protecting the host against pathogenic and sterile stressors by initiating inflammation. Upon activation, these complexes directly regulate the proteolytic processing and activation of proinflammatory cytokines interleukin (IL)-1ß and IL-18 to induce a potent inflammatory response, and induce a programmed form of cell death called pyroptosis to expose intracellular pathogens to the surveillance of the immune system, thus perpetuating inflammation. There are various types of inflammasome complexes, with the NLRP1 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-1) inflammasome being the first one identified and currently recognized as the predominant inflammasome sensor protein in human keratinocytes. Human NLRP1 exhibits a unique domain structure, containing both an N-terminal pyrin (PYD) domain and an effector C-terminal caspase recruitment domain (CARD). It can be activated by diverse stimuli, such as viruses, ultraviolet B radiation and ribotoxic stress responses. Specific mutations in NLRP1 or related genes have been associated with rare monogenic skin disorders, such as multiple self-healing palmoplantar carcinoma; familial keratosis lichenoides chronica; autoinflammation with arthritis and dyskeratosis; and dipeptidyl peptidase 9 deficiency. Recent research breakthroughs have also highlighted the involvement of dysfunctions in the NLRP1 pathway in a handful of seemingly unrelated dermatological conditions. These range from monogenic autoinflammatory diseases to polygenic autoimmune diseases such as vitiligo, psoriasis, atopic dermatitis and skin cancer, including squamous cell carcinoma, melanoma and Kaposi sarcoma. Additionally, emerging evidence implicates NLRP1 in systemic lupus erythematosus, pemphigus vulgaris, Addison disease, Papillon-Lefèvre syndrome and leprosy. The aim of this review is to shed light on the implications of pathological dysregulation of the NLRP1 inflammasome in skin diseases and investigate the potential rationale for targeting this pathway as a future therapeutic approach.

Curcumin effects on age-related changes in oral immunity: an in vivo study.

The current study aimed to investigate the effects of ageing on oral immunity using ß-defensin (DEFB) 1/2 as a marker and evaluate the effects of curcumin (CUR) on these processes. The study sample included thirty male C57BL/6J mice divided into three groups based on the treatment method used. The young control (YC) and old control (OC) groups received 0·5 % methylcellulose-400 (CUR vehicle) orally for 5 days, whereas the CUR group of older mice received a CUR solution suspended in 0·5 % methylcellulose-400 (dose: 3·0 mg/kg body). DEFB1/2 and immune indicator levels were measured in the saliva and salivary glands post-treatment. The saliva volume and protein content were significantly reduced in the OC group compared with the YC group. CUR administration restored these parameters, decreased DEFB1 expression in the salivary gland and increased DEFB1/2 secretion and DEFB2 expression. These findings were supported by epigenetic gene regulation and partial cytokine activation from changes in WD40 repeat protein 5, TNF alpha and IL-1beta. CUR can partially restore age-related changes in oral immune responses and promote oral health, thereby preventing frailty in the older population through a nutritional therapeutic pathway.

Metabolic Dysfunction-Associated Fatty Liver Disease on Distinct Microbial Communities at the Bacterial Phylum Level.

INTRODUCTION: Limited data are available on the correlation between microbial communities and metabolic dysfunction-associated fatty liver disease (MAFLD). This study aimed to evaluate the influence of MAFLD on diverse microbial communities. METHODS: We recruited 43 patients with a nonviral liver disease. Enrolled patients were divided into two groups according to MAFLD criteria. The fecal microbial composition was evaluated using the variable V3-V4 region of the 16S ribosomal RNA region, which was amplified using polymerase chain reaction. First, we assessed the influence of MAFLD on distinct microbial communities at the bacterial phylum level. Next, the correlation between the microbial communities and diversity in patients with MAFLD was evaluated. RESULTS: Among the enrolled participants, the non-MAFLD and MAFLD groups consisted of 21 and 22 patients, respectively. Sequences were distributed among ten bacterial phyla. The relative abundance of Firmicutes was significantly higher in the MAFLD group than in the non-MAFLD group (p = 0.014). The microbial diversity was not significantly influenced by the presence of MAFLD (Chao-1 index: p = 0.215 and Shannon index: p = 0.174, respectively); nonetheless, the correlation coefficient between the abundances of Firmicutes and microbial diversity was higher in the non-MAFLD group than in the MAFLD group. CONCLUSION: The presence of MAFLD increased the relative abundances of Firmicutes at the bacterial phylum level, which may cause the discrepancy between the abundances of Firmicutes and diversity in patients with MAFLD.

Electrophilic properties of itaconate and derivatives regulate the IκBζ-ATF3 inflammatory axis.

Metabolic regulation has been recognized as a powerful principle guiding immune responses. Inflammatory macrophages undergo extensive metabolic rewiring 1 marked by the production of substantial amounts of itaconate, which has recently been described as an immunoregulatory metabolite 2 . Itaconate and its membrane-permeable derivative dimethyl itaconate (DI) selectively inhibit a subset of cytokines 2 , including IL-6 and IL-12 but not TNF. The major effects of itaconate on cellular metabolism during macrophage activation have been attributed to the inhibition of succinate dehydrogenase2,3, yet this inhibition alone is not sufficient to account for the pronounced immunoregulatory effects observed in the case of DI. Furthermore, the regulatory pathway responsible for such selective effects of itaconate and DI on the inflammatory program has not been defined. Here we show that itaconate and DI induce electrophilic stress, react with glutathione and subsequently induce both Nrf2 (also known as NFE2L2)-dependent and -independent responses. We find that electrophilic stress can selectively regulate secondary, but not primary, transcriptional responses to toll-like receptor stimulation via inhibition of IκBζ protein induction. The regulation of IκBζ is independent of Nrf2, and we identify ATF3 as its key mediator. The inhibitory effect is conserved across species and cell types, and the in vivo administration of DI can ameliorate IL-17-IκBζ-driven skin pathology in a mouse model of psoriasis, highlighting the therapeutic potential of this regulatory pathway. Our results demonstrate that targeting the DI-IκBζ regulatory axis could be an important new strategy for the treatment of IL-17-IκBζ-mediated autoimmune diseases.

Regulation of Chloride Channels by Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor-Induced α-Defensin 5.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are used to treat non-small cell lung cancer with EGFR mutations. However, first-generation erlotinib and second-generation afatinib often cause diarrhea, which may develop because of the association between EGFR-TKIs and the chloride channel or abnormalities in the intestinal microbiota due to disruption of the intestinal immune system. As reports on the effects of EGFR-TKIs on intestinal immunity are lacking, we aimed to determine whether the intestinal immune system is involved in the molecular effects of EGFR-TKIs on chloride channels using Caco-2 cells. Initially, we evaluated the association of chloride channels with α-defensin 5 (DEFA5), a marker of intestinal immunity. Erlotinib and afatinib significantly increased the extracellularly secreted DEFA5 level and autophagy-related 16-like 1 and X-box binding protein 1 transcript levels, indicative of enhanced granule exocytosis. Conversely, intracellular DEFA5 and Toll-like receptor 4 protein expression and tumor necrosis factor-α transcript levels decreased significantly, suggesting that Toll-like receptor 4 suppression repressed DEFA5 production. Furthermore, among the chloride channels, DEFA5 was found to significantly increase the transcript levels of cystic fibrosis transmembrane conductance regulators. These results indicate that DEFA5 plays a significant role in the mechanism of chloride channel-mediated diarrhea induced by EGFR-TKIs. Therefore, we successfully elucidated the potential host action of DEFA5 in cancer therapy for the first time.

Loss of FCHSD1 leads to amelioration of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD/emphysema) is a life-threatening disorder and there are few effective therapies. Cigarette smoke-induced oxidative stress, airway inflammation, and apoptosis of lung cells have been reported to be involved in the pathogenesis of COPD/emphysema and lead to alveolar septal destruction. Here we show that the expression level of FCH and double SH3 domains 1 (FCHSD1) was drastically increased in mice in response to elastase instillation, an experimental model of COPD. FCHSD1 is a member of the F-BAR family with two SH3 domains. We found that Fchsd1 knockout (Fchsd1-/-) mice were protected against airspace enlargement induced by elastase. Elastase-instilled lungs of Fchsd1-/- mice showed reduced inflammation and apoptosis compared with WT mice. We also found that elastase-induced reduction of Sirtuin 1 (SIRT1) levels, a histone deacetylase reported to protect against emphysema, was attenuated in the lungs of Fchsd1-/- mice. Furthermore, FCHSD1 deficiency enhanced nuclear translocation of nuclear factor-like 2 (NRF2), a redox-sensitive transcription factor, following H2O2 stimulation. Conversely, Fchsd1 overexpression inhibited NRF2 nuclear translocation and increased the reduction of SIRT1 levels. Notably, FCHSD1 interacted with NRF2 and SNX9. Our results show that FCHSD1 forms a multicomplex with NRF2 and SNX9 in the cytosol that prevents NRF2 from translocating to the nucleus. We propose that FCHSD1 promotes initiation of emphysema development by inhibiting nuclear translocation of NRF2, which leads to down-regulation of SIRT1.

The IκB kinase complex regulates the stability of cytokine-encoding mRNA induced by TLR-IL-1R by controlling degradation of regnase-1.

Toll-like receptor (TLR) signaling activates the inhibitor of transcription factor NF-κB (IκB) kinase (IKK) complex, which governs NF-κB-mediated transcription during inflammation. The RNase regnase-1 serves a critical role in preventing autoimmunity by controlling the stability of mRNAs that encode cytokines. Here we show that the IKK complex controlled the stability of mRNA for interleukin 6 (IL-6) by phosphorylating regnase-1 in response to stimulation via the IL-1 receptor (IL-1R) or TLR. Phosphorylated regnase-1 underwent ubiquitination and degradation. Regnase-1 was reexpressed in IL-1R- or TLR-activated cells after a period of lower expression. Regnase-1 mRNA was negatively regulated by regnase-1 itself via a stem-loop region present in the regnase-1 3' untranslated region. Our data demonstrate that the IKK complex phosphorylates not only IκBα, thereby activating transcription, but also regnase-1, thereby releasing a 'brake' on IL-6 mRNA expression.

Characterisation of IL-1 family members in Sweet syndrome highlights the overexpression of IL-1ß and IL-1R3 as possible therapeutic targets.

Sweet syndrome (SS) as a prototypic neutrophilic dermatosis (NDs) shares certain clinical and histologic features with monogenic auto-inflammatory disorders in which interleukin (IL)-1 cytokine family members play an important role. This has led to the proposal that NDs are polygenic auto-inflammatory diseases and has fuelled research to further understand the role of IL-1 family members in the pathogenesis of NDs. The aim of this study was to characterise the expression of the IL-1 family members IL-1ß, IL-36γ, IL-33 and IL-1R3 (IL-1RaP) in SS. The expression profile of IL-1ß, IL-33, IL-36γ and their common co-receptor IL-1R3 was analysed by immunohistochemistry, in situ hybridisation and double immunofluorescence (IF) in healthy control skin (HC) and lesional skin samples of SS. Marked overexpression of IL-1ß in the dermis of SS (p < 0.001), and a non-significant increase in dermal (p = 0.087) and epidermal (p = 0.345) IL-36γ expression compared to HC was observed. Significantly increased IL-1R3 expression within the dermal infiltrate of SS skin samples (p = 0.02) was also observed, whereas no difference in IL-33 expression was found between SS and HC (p = 0.7139). In situ hybridisation revealed a good correlation between gene expression levels and the above protein expression levels. Double IF identifies neutrophils and macrophages as the predominant sources of IL-1ß. This study shows that IL-1ß produced by macrophages and neutrophils and IL-1R3 are significantly overexpressed in SS, thereby indicating a potential pathogenic role for this cytokine and receptor in SS.

Divergent in situ expression of IL-31 and IL-31RA between bullous pemphigoid and pemphigus vulgaris.

Bullous pemphigoid (BP) and pemphigus vulgaris (PV) are two major autoimmune blistering skin diseases. Unlike PV, BP is accompanied by intense pruritus, suggesting possible involvement of the pruritogenic cytokine IL-31. However, the underlying mechanisms of the clinical difference between BP and PV in terms of pruritus are not fully understood. To compare the expression levels of IL-31 and its receptor IL-31RA in the lesional skin, including peripheral nerves in BP and PV patients, immunohistochemical staining for IL-31 and IL-31RA was performed in skin samples of BP and PV patients and healthy controls (HC). The IL-31RA-expressing area in epidermis and peripheral nerves was analysed using ImageJ and the percentage of positive cells for IL-31/IL-31RA in dermal infiltrating cells was manually quantified. Quantitative analyses revealed that IL-31/IL-31RA expressions in the epidermis and dermal infiltrate were significantly increased in BP compared to PV and HC. The difference between BP and PV became more obvious when advanced bullous lesions were compared. Peripheral nerves in BP lesions presented significantly higher IL-31RA expression compared to PV lesions. In conclusion, we found significantly augmented expressions of IL-31/IL-31RA in BP lesions, including peripheral nerves, in comparison to PV. These results suggest a possible contribution of IL-31/IL-31RA signalling to the difference between BP and PV in the facilitation of pruritus and local skin inflammation, raising the possibility of therapeutic targeting of the IL-31/IL-31RA pathway in BP patients.

Impact of liver fibrosis on the relative abundance of a urease-positive Streptococcus salivarius group from saliva in patients with chronic liver disease.

AIM: We performed genomic analysis to study the relative abundance of a urease-positive Streptococcus salivarius group isolated from the saliva of patients with chronic liver disease. METHODS: Male and female patients with chronic liver disease aged over 20 years were included. First, we assessed the frequency and type of the S. salivarius group isolated from oral saliva using molecular biology techniques based on 16S rRNA and dephospho-coenzyme A kinase gene sequencing. Next, we assessed the correlation between the urease positivity rate in the S. salivarius group isolated from oral saliva and liver fibrosis based on chronic liver disease. Urease-positive strains were identified by the urease test using urea broth (Difco, Franklin Lakes, NJ, USA). Liver fibrosis was evaluated by the liver stiffness measurement value based on magnetic resonance elastography. RESULTS: A total of 45 patients identified using the multiplex polymerase chain reaction for the 16S rRNA gene were tested using the multiplex polymerase chain reaction for the dephospho-coenzyme A kinase gene. Confirming the strains detected in each of the 45 patients, urease-positive S. salivarius was detected in 28 patients (62%), urease-negative S. salivarius in 25 patients (56%), and urease-positive Streptococcus vestibularis in 12 patients (27%). There was no patient with urease-negative S. vestibularis. The urease-positive rate of the S. salivarius group in the cirrhosis and non-cirrhosis groups were 82.2% and 39.2%, respectively. The liver cirrhosis group had a higher urease positivity rate than the non-cirrhotic group (p < 0.001). CONCLUSIONS: Liver fibrosis influences the frequency of a urease-positive S. salivarius group isolated from oral saliva.

Identification of an atypical monocyte and committed progenitor involved in fibrosis.

Monocytes and macrophages comprise a variety of subsets with diverse functions. It is thought that these cells play a crucial role in homeostasis of peripheral organs, key immunological processes and development of various diseases. Among these diseases, fibrosis is a life-threatening disease of unknown aetiology. Its pathogenesis is poorly understood, and there are few effective therapies. The development of fibrosis is associated with activation of monocytes and macrophages. However, the specific subtypes of monocytes and macrophages that are involved in fibrosis have not yet been identified. Here we show that Ceacam1+Msr1+Ly6C-F4/80-Mac1+ monocytes, which we term segregated-nucleus-containing atypical monocytes (SatM), share granulocyte characteristics, are regulated by CCAAT/enhancer binding protein ß (C/EBPß), and are critical for fibrosis. Cebpb deficiency results in a complete lack of SatM. Furthermore, the development of bleomycin-induced fibrosis, but not inflammation, was prevented in chimaeric mice with Cebpb-/- haematopoietic cells. Adoptive transfer of SatM into Cebpb-/- mice resulted in fibrosis. Notably, SatM are derived from Ly6C-FcεRI+ granulocyte/macrophage progenitors, and a newly identified SatM progenitor downstream of Ly6C-FcεRI+ granulocyte/macrophage progenitors, but not from macrophage/dendritic-cell progenitors. Our results show that SatM are critical for fibrosis and that C/EBPß licenses differentiation of SatM from their committed progenitor.

Computational estimation of sediment symbiotic bacterial structures of seagrasses overgrowing downstream of onshore aquaculture.

Coastal seagrass meadows are essential in blue carbon and aquatic ecosystem services. However, this ecosystem has suffered severe eutrophication and destruction due to the expansion of aquaculture. Therefore, methods for the flourishing of seagrass are still being explored. Here, data from 49 public coastal surveys on the distribution of seagrass and seaweed around the onshore aquaculture facilities are revalidated, and an exceptional area where the seagrass Zostera marina thrives was found near the shore downstream of the onshore aquaculture facility. To evaluate the characteristics of the sediment for growing seagrass, physicochemical properties and bacterial ecological evaluations of the sediment were conducted. Evaluation of chemical properties in seagrass sediments confirmed a significant increase in total carbon and a decrease in zinc content. Association analysis and linear discriminant analysis refined bacterial candidates specified in seagrass overgrown- and nonovergrown-sediment. Energy landscape analysis indicated that the symbiotic bacterial groups of seagrass sediment were strongly affected by the distance close to the seagrass-growing aquaculture facility despite their bacterial population appearing to fluctuate seasonally. The bacterial population there showed an apparent decrease in the pathogen candidates belonging to the order Flavobacteriales. Moreover, structure equation modeling and a linear non-Gaussian acyclic model based on the machine learning data estimated an optimal sediment symbiotic bacterial group candidate for seagrass growth as follows: the Lachnospiraceae and Ruminococcaceae families as gut-inhabitant bacteria, Rhodobacteraceae as photosynthetic bacteria, and Desulfobulbaceae as cable bacteria modulating oxygen or nitrate reduction and oxidation of sulfide. These observations confer a novel perspective on the sediment symbiotic bacterial structures critical for blue carbon and low-pathogenic marine ecosystems in aquaculture.

Introduction of direct-acting antiviral agents alters frequencies of anti-GPIIb/IIIa antibody-producing B cells in chronic hepatitis C patients with thrombocytopenia.

The pathogenesis of thrombocytopenia in chronic hepatitis C (CHC) conceivably involves autoimmunity; however, the dynamics of autoantibodies and other autoimmune mechanisms remain unclear. In this study, we examined the changes in the frequency of anti-glycoprotein (GP) IIb/IIIa antibody-producing B cells and the levels of plasma B-cell-activating factor (BAFF), a proliferation-inducing ligand (APRIL), and interleukin (IL)-21 following treatment of CHC with direct-acting antiviral agents (DAA). We recruited 28 patients with CHC who underwent treatment with DAA for 8-12 weeks and subsequently tested negative for serum hepatitis C virus RNA. Thirty healthy controls were recruited for comparison. Platelet counts increased significantly (p = .016), and the frequency of anti-GPIIb/IIIa antibody-producing B cells decreased significantly (p = .002) in CHC patients with thrombocytopenia at the end of treatment (EOT) than before DAA treatment (baseline). However, these changes were not observed in CHC patients without thrombocytopenia. Plasma BAFF levels in CHC patients with thrombocytopenia significantly decreased from baseline to EOT (p = .002). Anti-GPIIb/IIIa antibody-producing B cells were positively correlated with plasma BAFF levels in these patients (r = 0.669, p = .039). These results suggest that DAA treatment suppresses the autoimmune response against platelets and improves thrombocytopenia.

What is the context? Production of antiplatelet antibodies is one of the mechanisms underlying thrombocytopenia in patients with chronic hepatitis C.Antiplatelet antibodies against platelet membrane glycoprotein (GP) IIb/IIIa are commonly detected in hepatitis C virus-associated immune thrombocytopenia.Hepatitis C virus elimination by direct-acting antiviral agents (DAA) improves thrombocytopenia in patients with hepatitis C; however, the dynamics of autoantibodies and other autoimmune mechanisms remain unclear.What is new? In this study, we determined whether DAA treatment can alter the autoimmune response against platelets and improve platelet count.The frequency of anti-GPIIb/IIIa antibody-producing B cells decreased significantly from the baseline following DAA treatment in chronic hepatitis C patients with thrombocytopenia.DAA treatment reduced the levels of B-cell-activating factor, a cytokine associated with autoantibody production.What is the impact? The study provides evidence that DAA treatment diminishes the autoimmune response to GPIIb/IIIa and, therefore, improves platelet counts in chronic hepatitis C patients with thrombocytopenia.