Identification of herbal drug extracts that promote growth of Akkermansia muciniphila in high-fat diet fed mice.

Disruption of the gut microbiota causes metabolic dysfunction, and intervention in the gut microbiota has the potential to improve host glucose metabolism. Akkermanisa muciniphila is an intestinal bacterium involved in anti-obesity and insulin resistance. Developing interventions to increase A. muciniphla would be useful for new treatment strategies. In this study, we screened herbal drug extracts that promoted the growth of A. muciniphila. Among the 123 herbal drugs, five herbal drug extracts significantly increased A. muciniphila DNA levels compared with that in controls. In particular, Dioscoreae rhizoma extract increased the growth of A. muciniphila in the intestines of mice fed a high-fat diet and improved obesity. It significantly reduced body weight gain, improved glucose tolerance even when the administration was initiated after the induction of dietary obesity. These results suggest that herbal drug extracts, such as Dioscoreae rhizome, that increase A. muciniphila could be a new therapeutic strategy for metabolic syndrome. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-024-00713-w.

Comparison of the efficacy of first­/second­generation EGFR­tyrosine kinase inhibitors and osimertinib for EGFR­mutant lung cancer with negative or low PD­L1 expression.

In epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) with negative or low programmed death ligand-1 (PD-L1) expression, the acquisition rate of the T790M mutation is higher after treatment with first-/second-generation EGFR-tyrosine kinase inhibitors (TKIs) and the progression-free survival (PFS) is longer in patients treated with osimertinib. The present study compared the clinical course after the initiation of each EGFR-TKI monotherapy in patients with EGFR-mutant NSCLC with negative or low PD-L1 expression. Data of patients with EGFR-mutant NSCLC with negative or low PD-L1 expression who were treated with EGFR-TKI monotherapy were retrieved and retrospectively analyzed. Between June 2013 and November 2023, 26 and 29 patients were treated with first-/second-generation EGFR-TKIs and osimertinib, respectively. The PFS time was longer in patients treated with osimertinib (median, 22.5 months) than in those treated with first-/second-generation EGFR-TKIs (median, 12.9 months). However, the EGFR-TKI treatment duration, defined as the PFS for osimertinib, or the sum of the PFS for first-/second-generation EGFR-TKIs and sequential osimertinib therapy after the acquisition of the T790M mutation, was similar between patients treated with first-/second-generation EGFR-TKIs (median, 23.0 months) and osimertinib (median, 22.5 months). The Cox proportional hazard model suggested that there was no significant difference in the EGFR-TKI treatment duration between patients treated with first-/second-generation EGFR-TKIs and patients treated with osimertinib (hazard ratio, 1.31, 95% CI, 0.55-3.13). In conclusion, first-/second-generation EGFR-TKIs and osimertinib were associated with a similar EGFR-TKI treatment duration in patients with EGFR-mutant NSCLC with negative or low PD-L1 expression. The findings suggested that both treatments are promising for this population.

History and future perspectives of adipose tissue macrophage biology.

Macrophages contribute to adipose tissue homeostasis; however, they are also thought to be responsible for insulin resistance in obesity. Macrophages, which were oversimplified in past methodologies, have become rather difficult to understand comprehensively as recent developments in research methodology have revealed their diversity. This review highlights recent studies on adipose tissue macrophages, identifies controversial issues that need to be resolved and proposes a scenario for further development of adipose tissue macrophage biology.

Immune Checkpoint Inhibitor Therapy for Patients With Non-small Cell Lung Cancer Ineligible for Platinum Doublet Chemotherapy.

BACKGROUND/AIM: Combined therapy with immune checkpoint inhibitors plus platinum doublet chemotherapy has a survival advantage over platinum doublet chemotherapy in patients with non-small cell lung cancer. However, a variety of factors make it difficult to administer treatment with platinum doublet chemotherapy in many patients in clinical practice and there are few reports on the efficacy and safety of first-line treatments with immune checkpoint inhibitors for patients who are ineligible for platinum doublet chemotherapy. This observational study aimed to evaluate the efficacy and safety of first-line immune checkpoint inhibitor therapy for this population. PATIENTS AND METHODS: We retrospectively assessed the survival and adverse events from the initiation of first-line immune checkpoint inhibitor therapy, including pembrolizumab or nivolumab plus ipilimumab in patients with non-small cell lung cancer who were ineligible for platinum doublet chemotherapy. RESULTS: Data from 48 patients were analyzed. Seventeen patients showed a performance status (PS) of ≥2 while 16 and 15 patients were considered ineligible for platinum doublet chemotherapy because of age and comorbidities, respectively. The median (95% confidential interval, CI) progression-free survival (PFS) and overall survival (OS) of the 48 patients were 7.1 (1.7-13.7) and 31.7 (8.8-not estimated) months, respectively. The two-year PFS and OS rates (95% CI) were 30.8% (18.2%-47.2%) and 50.7% (33.7%-67.7%), respectively. In patients with a PS of ≥2, the median (95% CI) PFS and OS were 1.6 (1.2-not estimated) and 5.5 (2.3-not estimated) months, respectively. The two-year PFS and OS rates (95% CI) were 34.3% (15.8%-59.2%) and 45.3% (22.2%-70.7%), respectively. CONCLUSION: Patients with non-small cell lung cancer and a PS of 0-1 who were ineligible for platinum doublet chemotherapy had favorable outcome after the initiation of ICI therapy, and even in patients with a PS of ≥2, they achieved high two-year PFS and OS rates.

Characterization of Diabetic Striatopathy With Repeated Follow-Up Using Multiple Imaging Studies.

Diabetic striatopathy is a rare condition with a prevalence of less than one in 100,000. Herein, we report a case of diabetic striatopathy exacerbated by hyperglycemia and hypoglycemia, with repeated follow-up with multiple imaging studies. This case suggested that putamen neuronal loss and dysfunction, gliosis, and ischemia are associated with diabetic striatopathy pathophysiology. In addition, striatal hyperintensity on T1-weighted MRI images was more pronounced after symptom remission when evaluated several times over a short period. Therefore, clinicians should be aware that even if MRI findings are normal in the very early stages of the onset of diabetic striatopathy, repeating MRIs at intervals may reveal typical findings.

Short-term recovery of insulin secretion in response to a meal is associated with future glycemic control in type 2 diabetes patients.

AIMS/INTRODUCTION: Endogenous insulin secretion could be recovered by improving hyperglycemia in patients with type 2 diabetes. This study aimed to investigate the association between short-term recovery of insulin secretion during hospitalization and clinical background or future glycemic control in patients with type 2 diabetes. MATERIALS AND METHODS: A total of 127 patients with type 2 diabetes were included. The recovery of endogenous insulin secretion was determined using the following indices: index A: fasting C-peptide index (CPI) at discharge - fasting CPI on admission; index B: postprandial CPI at discharge - postprandial CPI on admission; and index C: Δ C-peptide immunoreactivity (CPR) (postprandial CPR - fasting CPR) at discharge - ΔCPR on admission. We examined the associations of each index with clinical background and future glycemic control measured by glycosylated hemoglobin and continuous glucose monitoring. RESULTS: Using index A and B, the age was significantly younger, whereas BMI and visceral fat area were significantly higher in the high-recovery group than in the low-recovery group. Changes in glycosylated hemoglobin levels were significantly greater at 6 and 12 months in the high-recovery group in the analysis of index C. The receiver operating characteristic curve analysis identified the index B and index C as indicators to predict glycosylated hemoglobin <7.0% at 6 months after discharge. Furthermore, index C was positively correlated with the time in the target glucose range, and inversely correlated with the standard deviation of glucose at 3 and 12 months after discharge. CONCLUSIONS: Short-term recovery of insulin secretion in response to a meal during hospitalization, evaluated with the index-C, might predict future glycemic control.

A Case Report of Anti-TIF1-γAntibody-Positive Dermatomyositis Concomitant with Small Cell Neuroendocrine Carcinoma of the Urinary Bladder.

Small cell neuroendocrine carcinoma is rare among urinary bladder cancer types, and to date, there are no case reports of concurrent antitranscriptional intermediary factor 1-γantibody-positive dermatomyositis. We describe the case of a 69-year-old Japanese man who presented with elevated creatine kinase levels and haematuria on medical examination. Approximately one month later, he developed dysphagia. Laryngoscopy confirmed laryngeal dysfunction. He also presented with muscle weakness and a skin rash. Magnetic resonance imaging of the upper extremities suggested bilateral brachial muscle myositis. He was diagnosed as having dermatomyositis and was later found to be positive for antitranscriptional intermediary factor 1-γ antibody. Computed tomography revealed an intravesical space-occupying lesion and right iliac lymphadenopathy, suggesting urinary bladder cancer. The patient was admitted to our hospital for treatment. Urinary bladder biopsy confirmed small cell neuroendocrine carcinoma because tumour cells were positive for synaptophysin, CD56, and chromogranin A. Thus, the patient was diagnosed as having an antitranscriptional intermediary factor 1-γantibody-positive dermatomyositis concomitant with urinary bladder small cell neuroendocrine carcinoma. The patient was treated with glucocorticoid and intravenous immune globulin therapy for dermatomyositis. Radiotherapy was selected for the carcinoma. Although muscle weakness and skin symptoms improved with treatment, dysphagia persisted. Furthermore, expression of the transcriptional intermediary factor 1-γ protein in tumour cells was also confirmed by immunohistochemistry, but the significance is unknown. It should be noted that antitranscriptional intermediary factor 1-γantibody-positive dermatomyositis can occur concomitantly with such a rare malignancy.

Isoxanthohumol improves obesity and glucose metabolism via inhibiting intestinal lipid absorption with a bloom of Akkermansia muciniphila in mice.

OBJECTIVE: Polyphenols have health-promoting effects, such as improving insulin resistance. Isoxanthohumol (IX), a prenylated flavonoid found in beer hops, has been suggested to reduce obesity and insulin resistance; however, the mechanism remains unknown. METHODS: High-fat diet-fed mice were administered IX. We analyzed glucose metabolism, gene expression profiles and histology of liver, epididymal adipose tissue and colon. Lipase activity, fecal lipid profiles and plasma metabolomic analysis were assessed. Fecal 16s rRNA sequencing was obtained and selected bacterial species were used for in vitro studies. Fecal microbiota transplantation and monocolonization were conducted to antibiotic-treated or germ-free (GF) mice. RESULTS: The administration of IX lowered weight gain, decreased steatohepatitis and improved glucose metabolism. Mechanistically, IX inhibited pancreatic lipase activity and lipid absorption by decreasing the expression of the fatty acid transporter CD36 in the small intestine, which was confirmed by increased lipid excretion in feces. IX administration increased markers of intestinal barrier function, including thickening the mucin layer and increasing caludin-1, a tight-junction related protein in the colon. In contrast, the effects of IX were nullified by antibiotics. As revealed using 16S rRNA sequencing, the microbial community structure changed with a significant increase in the abundance of Akkermansia muciniphila in the IX-treated group. An anaerobic chamber study showed that IX selectively promoted the growth of A. muciniphila while exhibiting antimicrobial activity against some Bacteroides and Clostridium species. To further explore the direct effect of A. muciniphila on lipid and glucose metabolism, we monocolonized either A. muciniphila or Bacteroides thetaiotaomicron to GF mice. A. muciniphila monocolonization decreased CD36 expression in the jejunum and improved glucose metabolism, with decreased levels of multiple classes of fatty acids determined using plasma metabolomic analysis. CONCLUSIONS: Our study demonstrated that IX prevents obesity and enhances glucose metabolism by inhibiting dietary fat absorption. This mechanism is linked to suppressing pancreatic lipase activity and shifts in microbial composition, notably an increase in A. muciniphila. These highlight new treatment strategies for preventing metabolic syndrome by boosting the gut microbiota with food components.

Hepatic FASN deficiency differentially affects nonalcoholic fatty liver disease and diabetes in mouse obesity models.

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes are interacting comorbidities of obesity, and increased hepatic de novo lipogenesis (DNL), driven by hyperinsulinemia and carbohydrate overload, contributes to their pathogenesis. Fatty acid synthase (FASN), a key enzyme of hepatic DNL, is upregulated in association with insulin resistance. However, the therapeutic potential of targeting FASN in hepatocytes for obesity-associated metabolic diseases is unknown. Here, we show that hepatic FASN deficiency differentially affects NAFLD and diabetes depending on the etiology of obesity. Hepatocyte-specific ablation of FASN ameliorated NAFLD and diabetes in melanocortin 4 receptor-deficient mice but not in mice with diet-induced obesity. In leptin-deficient mice, FASN ablation alleviated hepatic steatosis and improved glucose tolerance but exacerbated fed hyperglycemia and liver dysfunction. The beneficial effects of hepatic FASN deficiency on NAFLD and glucose metabolism were associated with suppression of DNL and attenuation of gluconeogenesis and fatty acid oxidation, respectively. The exacerbation of fed hyperglycemia by FASN ablation in leptin-deficient mice appeared attributable to impairment of hepatic glucose uptake triggered by glycogen accumulation and citrate-mediated inhibition of glycolysis. Further investigation of the therapeutic potential of hepatic FASN inhibition for NAFLD and diabetes in humans should thus consider the etiology of obesity.

Peripheral CD4 memory T cells predict the efficacy of immune checkpoint inhibitor therapy in patients with non-small cell lung cancer.

Immune checkpoint inhibitors have significantly improved the prognosis in patients with non-small cell lung cancer, compared with cytotoxic agents. However, the prediction of treatment response is often difficult, even after assessing the tumor programmed death-ligand 1 expression. We conducted this observational study to analyze the association between the differentiation of peripheral CD4 + T cells and the efficacy of immune checkpoint inhibitor therapy. We enrolled patients who were diagnosed with non-small cell lung cancer and received immune checkpoint inhibitor therapy between 2020 and 2022. Blood samples were collected at the start of immune checkpoint inhibitor therapy, and the expressions of PD-1, CCR7, and CD45RA in peripheral CD4 + T cells were analyzed by flow cytometry. The association between the findings of flow cytometry and survival after the initiation of the immune checkpoint inhibitor therapy was evaluated. Forty patients with non-small cell lung cancer were enrolled. The Cox proportional hazards model showed that an increased proportion of CD45RA-CD4 + T cells was associated with a reduced risk of progression after adjustment for performance status, tumor programmed death-ligand 1 expression level, mutation status of the epidermal growth factor receptor gene, and combined therapy with cytotoxic agents. The present study showed that the proportion of peripheral CD45RA- CD4 + T cells was associated with progression-free survival after the initiation of immune checkpoint inhibitor therapy, independent of several clinical factors.

An autopsy case of anti-MDA5 antibody-positive amyopathic dermatomyositis with an initial manifestation of panniculitis on the left upper arm.

A 53-year-old man was presented with refractory panniculitis on the left upper arm that had persisted for 10 months. The patient was diagnosed with lupus profundus, wherein oral glucocorticoid therapy was initiated. Four months prior, ulceration was observed in the same area. Dapson was administered instead, scarring the ulcer but enlarging the panniculitis. Five weeks earlier, he developed a fever, productive cough, and dyspnoea. Three weeks earlier, a skin rash was observed on the forehead, left auricle posterior to the neck, and extensor aspect of the left elbow. Chest computed tomography showed pneumonia in the right lung, after which the patient's dyspnoea worsened. The patient was admitted and diagnosed with anti-MDA5 antibody-positive amyopathic dermatomyositis (ADM) based on skin findings, hyperferritinaemia, and rapidly progressive diffuse lung shadows. Glucocorticoid pulse therapy, intravenous cyclophosphamide, and tacrolimus were initiated, and later, plasma exchange therapy was combined. However, his condition worsened and required management with extracorporeal membrane oxygenation. The patient expired on day 28 after hospitalisation. An autopsy revealed hyalinising to fibrotic stages of diffuse alveolar damage. Strong expression of myxovirus resistance protein A was observed in three skin biopsy specimens from the time of initial onset, consistent with ADM. Anti-MDA5 antibody-positive ADM not only manifests typical cutaneous symptoms, but also rarely occurs with localised panniculitis, such as in the present case. In patients with panniculitis of unknown aetiology, the possibility of initial symptoms of ADM should be included in the differential diagnosis.

Association Between the Severity of Immune-related Adverse Events and the Prognosis in Patients With Non-small Cell Lung Cancer Receiving Treatment With Immune Checkpoint Inhibitors.

BACKGROUND/AIM: Among patients with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (ICI), survival is reported to be longer in those experiencing immune-related adverse events (irAEs). We evaluated the progression-free survival (PFS) in the absence of further treatment after ICI therapy was discontinued because of the emergence of irAEs in patients with NSCLC. PATIENTS AND METHODS: Data from patients with NSCLC in whom ICI therapy was discontinued because of the development of irAEs were retrospectively analyzed. The primary endpoint was the PFS from the last day of administration of ICIs, in the absence of any further treatment. RESULTS: A total of 162 patients with NSCLC received treatment with ICIs between January 2016 and December 2021. Among them, ICI therapy was discontinued in 33 patients because of the appearance of irAEs. The median (95% confidence interval) PFS in the absence of any treatment after the last administration of ICIs was 7.2 (4.2-12.3) months. According to the Common Terminology Criteria for Adverse Events, the Cox proportional hazards model was used to identify the severity of irAEs, which were determined to be significantly associated with the PFS in the absence of any further treatment after the last administration of ICI therapy. CONCLUSION: Although the present study showed that the PFS in patients with NSCLC was relatively long in the absence of any further treatment after the last administration of ICIs, the PFS was associated with the severity of the irAEs, and some patients showed early disease progression or death.

Thrombotic thrombocytopenic purpura that developed 3 years after systemic lupus erythematosus had remitted with rituximab therapy.

Patients with systemic lupus erythematosus (SLE) occasionally develop thrombotic thrombocytopenic purpura (TTP), which can be fatal. Here, we report a case of TTP developing 3 years after SLE remitted with rituximab (RTX) therapy. A 50-year-old woman was treated with RTX for marked immune thrombocytopenic purpura and autoimmune haemolytic anaemia due to SLE relapse. After induction of remission, she was treated with prednisolone alone without maintenance therapy with RTX. Approximately 3 years later, she was readmitted with marked thrombocytopenia and severe renal dysfunction. On admission, she was diagnosed with TTP for the first time based on severe reduction in a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity and detection of ADAMTS13 inhibitors. CD19+ B cells in the patient's serum increased to 34%, suggesting that B cells had reactivated once the effect of RTX had subsided. The patient was successfully treated with plasmapheresis, glucocorticoid pulse therapy, and RTX. There are no previous reports of newly diagnosed TTP with ADAMTS13 inhibitor production after having achieved remission of SLE with RTX. Therefore, our report also discusses the potential mechanisms of production of new autoantibodies after B-cell depletion therapy.

Heterogeneity of adipose tissue-resident macrophages-beyond M1/M2 paradigm.

Adipose tissue-resident macrophages (ATMs) are reported to be important for maintaining adipose tissue remodeling and homeostasis. ATMs were classified for the first time in 2007 into the M1 and M2 types. This theory suggests that in the non-obese adipose tissue, the anti-inflammatory, alternatively activated macrophages (AAMs) predominate, and regulate tissue homeostasis, remodeling, and insulin sensitivity. On the other hand, classically activated M1-type macrophages increase rapidly in obesity, secrete inflammatory cytokines, such as TNFα and IL-6, and induce insulin resistance. In recent years, experimental findings that cannot be explained by this theory have been clarified one after another and the theory is being reconsidered. In this review, based on recent findings, we summarize reports on the novel metabolic regulatory functions of ATMs beyond the M1/M2 paradigm.

Associations of immune checkpoint inhibitor therapy efficacy with clinical parameters and tumor­infiltrating CD68­positive cell counts in patients with EGFR­mutant non­small cell lung cancer.

Immune checkpoint inhibitor (ICI) therapy has been less effective in patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations than in patients with EGFR wild-type NSCLC. This retrospective study was conducted to investigate the associations of clinical parameters with the efficacy of ICI therapy in patients with EGFR-mutant NSCLC. Clinical information was retrieved from the medical charts, and immunohistochemical analysis was performed in some cases to determine the tumor-infiltrating CD68-positive cell count. Data from 46 patients were included in the analysis. The median (95% confidence interval) progression-free survival and overall survival from the initiation of ICI therapy was 1.4 months (1.0-1.7 months) and 6.4 months (3.9-19.0 months), respectively. Analysis using a Cox proportional hazards model revealed that tumor programmed death-ligand 1 expression was associated with the overall survival of patients with EGFR-mutant NSCLC after ICI treatment. The tumor-infiltrating CD68-positive cell count was evaluated in 11 patients. Comparison using the log-rank test revealed that the progression-free survival time after ICI treatment was longer in the patients with lower tumor-infiltrating CD68-positive cell counts than those with higher tumor-infiltrating CD68-positive cell counts. The present analysis demonstrated that PD-L1 expression and the tumor-infiltrating CD68-positive cell count may be associated with the efficacy of ICI therapy in patients with NSCLC harboring EGFR mutations.

PDGF receptor signal mediates the contribution of Nestin-positive cell lineage to subcutaneous fat development.

The beiging of white adipose tissue (WAT) is expected to improve systemic metabolic conditions; however, the regulation and developmental origin of this process remain insufficiently understood. In the present study, the implication of platelet-derived growth factor receptor alpha (PDGFRα) was examined in the beiging of inguinal WAT (ingWAT) of neonatal mice. Using in vivo Nestin expressing cell (Nestin+) lineage tracing and deletion mouse models, we found that, in the mice with Pdgfra gene inactivation in Nestin+ lineage (N-PRα-KO mice), the growth of inguinal WAT (ingWAT) was suppressed during neonatal periods as compared with control wild-type mice. In the ingWAT of N-PRα-KO mice, the beige adipocytes appeared earlier that were accompanied by the increased expressions of both adipogenic and beiging markers compared to control wild-type mice. In the perivascular adipocyte progenitor cell (APC) niche of ingWAT, many PDGFRα+ cells of Nestin+ lineage were recruited in Pdgfra-preserving control mice, but were largely decreased in N-PRα-KO mice. This PDGFRα+ cell depletion was replenished by PDGFRα+ cells of non-Nestin+ lineage, unexpectedly resulting in an increase of total PDGFRα+ cell number in APC niche of N-PRα-KO mice over that of control mice. These represented a potent homeostatic control of PDGFRα+ cells between Nestin+ and non-Nestin+ lineages that was accompanied by the active adipogenesis and beiging as well as small WAT depot. This highly plastic nature of PDGFRα+ cells in APC niche may contribute to the WAT remodeling for the therapeutic purpose against metabolic diseases.

Efficacy of immune checkpoint inhibitor therapy in patients with pulmonary sarcomatoid carcinoma in clinical practice.

OBJECTIVE: Studies have suggested the potential efficacy of immune checkpoint inhibitors (ICIs) for pulmonary sarcomatoid carcinoma. This multicenter observational study was conducted to evaluate the efficacy of systemic ICI therapy and chemoradiation followed by durvalumab therapy for pulmonary sarcomatoid carcinoma. METHODS: We analyzed the data of patients with pulmonary sarcomatoid carcinoma who received systemic ICI therapy or chemoradiation followed by durvalumab therapy between 2016 and 2022. RESULTS: In this study, data of a total of 22 patients who received systemic ICI therapy and four patients who received chemoradiation followed by durvalumab therapy were analyzed. In the patients who received systemic ICI therapy, the median progression-free survival after initiation of therapy was 9.6 months, and the overall survival did not reach the median. The 1-year progression-free survival rate and overall survival rate were estimated to be 45.5% and 50.1%, respectively. Although the log-rank test revealed no significant association between the tumor expression level of programmed death ligand-1 (tumor proportion score evaluated using 22C3 antibody: ≥50% vs. <50%) and the survival duration, the majority of patients showing long-term survival showed a tumor proportion score of ≥50%. Of four patients treated with chemoradiation followed by durvalumab therapy, two patients showed an overall survival of ≥30 months, whereas the remaining two patients died within 12 months. CONCLUSION: The progression-free survival of patients who received systemic ICI therapy was 9.6 months, suggesting that ICI therapy might be effective in patients with pulmonary sarcomatoid carcinoma.

N-glycan in the variable region of monoclonal ACPA (CCP-Ab1) promotes the exacerbation of experimental arthritis.

OBJECTIVES: The variable region of most ACPA IgG molecules in the serum of RA patients carries N-glycan (N-glycanV). To analyse the pathogenicity of N-glycanV of ACPAs, we analysed the pathogenicity of a monoclonal ACPA, CCP-Ab1, with or without N-glycanV, which had been isolated from a patient with RA. METHODS: CCP-Ab1 with no N-glycosylation site in the variable region (CCP-Ab1 N-rev) was generated, and antigen binding, the effect on in vitro differentiation of osteoclasts from bone marrow mononuclear cells of autoimmune arthritis-prone SKG mice (the cell size of TRAP+ cells and bone resorption capacity) and the in vivo effect on the onset or exacerbation of autoimmune arthritis in SKG mice were evaluated in comparison with glycosylated CCP-Ab1. RESULTS: Amino acid residues in citrullinated peptide (cfc1), which are essential for binding to CCP-Ab1 N-rev and original CCP-Ab1, were almost identical. The size of TRAP+ cells was significantly larger and osteoclast bone resorption capacity was enhanced in the presence of CCP-Ab1, but not with CCP-Ab1 N-rev. This enhancing activity required the sialic acid of the N-glycan and Fc region of CCP-Ab1. CCP-Ab1, but not CCP-Ab1 N-rev, induced the exacerbation of experimental arthritis in the SKG mouse model. CONCLUSIONS: These data showed that N-glycanV was required for promoting osteoclast differentiation and bone resorption activity in both in vitro and in vivo assays. The present study demonstrated the important role of N-glycanV in the exacerbation of experimental arthritis by ACPAs.

Impact of Vancomycin Treatment and Gut Microbiota on Bile Acid Metabolism and the Development of Non-Alcoholic Steatohepatitis in Mice.

The potential roles of the gut microbiota in the pathogenesis of non-alcoholic fatty liver disease, including non-alcoholic steatohepatitis (NASH), have attracted increased interest. We have investigated the links between gut microbiota and NASH development in Tsumura-Suzuki non-obese mice fed a high-fat/cholesterol/cholate-based (iHFC) diet that exhibit advanced liver fibrosis using antibiotic treatments. The administration of vancomycin, which targets Gram-positive organisms, exacerbated the progression of liver damage, steatohepatitis, and fibrosis in iHFC-fed mice, but not in mice fed a normal diet. F4/80+-recruited macrophages were more abundant in the liver of vancomycin-treated iHFC-fed mice. The infiltration of CD11c+-recruited macrophages into the liver, forming hepatic crown-like structures, was enhanced by vancomycin treatment. The co-localization of this macrophage subset with collagen was greatly augmented in the liver of vancomycin-treated iHFC-fed mice. These changes were rarely seen with the administration of metronidazole, which targets anaerobic organisms, in iHFC-fed mice. Finally, the vancomycin treatment dramatically modulated the level and composition of bile acid in iHFC-fed mice. Thus, our data demonstrate that changes in inflammation and fibrosis in the liver by the iHFC diet can be modified by antibiotic-induced changes in gut microbiota and shed light on their roles in the pathogenesis of advanced liver fibrosis.