Fibrocyte Phenotype of ENTPD1+CD55+ Cells and Its Association with Pain in Osteoarthritic Synovium.

Osteoarthritis (OA) is a prevalent degenerative joint disorder characterized by cartilage erosion, structural changes, and inflammation. Synovial fibroblasts play a crucial role in OA pathophysiology, with abnormal fibroblastic cells contributing significantly to joint pathology. Fibrocytes, expressing markers of both hematopoietic and stromal cells, are implicated in inflammation and fibrosis, yet their marker and role in OA remain unclear. ENTPD1, an ectonucleotidase involved in purinergic signaling and expressed in specific fibroblasts in fibrotic conditions, led us to speculate that ENTPD1 plays a role in OA pathology by being expressed in fibrocytes. This study aimed to investigate the phenotype of ENTPD1+CD55+ and ENTPD1-CD55+ synovial fibroblasts in OA patients. Proteomic analysis revealed a distinct molecular profile in ENTPD1+CD55+ cells, including the upregulation of fibrocyte markers and extracellular matrix-related proteins. Pathway analysis suggested shared mechanisms between OA and rheumatoid arthritis. Correlation analysis revealed an association between ENTPD1+CD55+ fibrocytes and resting pain in OA. These findings highlight the potential involvement of ENTPD1 in OA pain and suggest avenues for targeted therapeutic strategies. Further research is needed to elucidate the underlying molecular mechanisms and validate potential therapeutic targets.

Assessment of inconsistencies in the solvent-accessible surfaces of proteins between crystal structures and solution structures observed by LC-MS.

Structural proteomics techniques are useful for identifying the binding sites of proteins. The surface of a target protein with and without a bound binding partner is artificially labeled using a hydroxy radical, deuterium, or a low-molecular-weight chemical, and the difference in the label strength with and without the bound partner is determined. Label strength maps are then prepared on the Protein Data Bank (PDB) structure to identify the binding surface. However, the surface-accessible sites determined using such structural proteomics methods are frequently inconsistent with those calculated based on PDB structures, speculating that the measurement determines chemical accessibility rather than solvent accessibility. In this study, the solvent-accessible surface of human serum albumin was analyzed using covalent protein labeling with varying concentrations of CH2O and then compared to surfaces derived from 27 PDB structures. The results indicated that inconsistencies in solvent-accessible surface area values calculated from PDB structures are not caused by the limited capabilities of liquid chromatography-mass spectrometry coupled with covalent protein painting but instead are due to the lack of PDB data representing the structures in solution.

Tyrosine Kinase Inhibitors Do Not Promote a Decrease in SARS-CoV-2 Anti-Spike IgG after BNT162b2 Vaccination in Chronic Myeloid Leukemia: A Prospective Observational Study.

We performed a prospective observational study of chronic myeloid leukemia (CML) patients after anti-SARS-CoV-2 BNT162b2 vaccination (VC). In total, 32 CML patients with tyrosine kinase inhibitor (TKI) therapy, 10 CML patients with treatment-free remission, and 16 healthy subjects participated in the study. From April 2021 to September 2021, all cases (median age = 58 years) were vaccinated twice. Immunoglobulin G for SARS-CoV-2 spike protein (S-IgG) was measured at three timepoints (before the first VC, 1−5 weeks after the second VC (T1), and approximately 6 months after the second VC (T2)). S-IgG was not observed before the first VC in any participant. At T1, all cases had acquired S-IgG. There were no significant differences in S-IgG levels among groups. A paired sample comparison of median S-IgG titers between T1 and T2 in all groups showed a significant reduction in T2 S-IgG titers. There were no significant differences in S-IgG levels among groups. When all patients were analyzed, those aged ≥58 years had significantly lower S-IgG levels than those aged <58 years at T1. The BNT162b2 vaccine was highly effective in CML patients with or without TKIs, and S-IgG levels were as persistent as those in healthy individuals.

[Desquamative esophagitis associated with unrelated allogeneic peripheral blood stem cell transplantation using the FBM conditioning regimen].

Desquamative esophagitis (DE) is a rare benign condition characterized by sheet-like shedding of esophageal squamous epithelial tissue. Although cases of drug-induced DE, such as those induced by direct oral anticoagulants, have been reported, cases of DE complicated with hematopoietic stem cell transplantation (HSCT) are rare. We herein report the case of a 52-year-old woman with FLT3-ITD mutation-positive acute myeloid leukemia who presented with DE immediately after HSCT. Allogeneic peripheral blood HSCT with FBM (fludarabine 180 mg/m2, busulfan 12.8 mg/m2, and melphalan 80 mg/m2) was performed during the first remission. Tacrolimus plus short-term methotrexate was planned for graft-versus-host disease prevention. Common Terminology Criteria for Adverse Events grade 3 equivalent vomiting was observed during treatment with the conditioning regimen. On day 5 after HSCT, a white band of 10 cm in length and 1 cm in width was discharged from the oral cavity during vomiting. Upper gastrointestinal endoscopy revealed mucosal detachment in the entire esophagus and the diagnosis of DE was made. DE improved on providing conservative treatment. We concluded that the mechanical pressure that developed on the esophagus due to frequent vomiting contributed to the mucosal detachment owing to regimen-related toxicity. Even in the FBM regimen, which is widely used as a conditioning regimen, caution is required to prevent DE.

Involvement of a cyclic adenosine monophosphate-dependent signal in the diet-induced canalicular trafficking of adenosine triphosphate-binding cassette transporter g5/g8.

UNLABELLED: The adenosine triphosphate-binding cassette (ABC) half-transporters Abcg5 and Abcg8 promote the secretion of neutral sterol into bile. Studies have demonstrated the diet-induced gene expression of these transporters, but the regulation of their trafficking when the nutritional status changes in the liver remains to be elucidated. Here, we generated a novel in vivo kinetic analysis that can monitor the intracellular trafficking of Abcg5/Abcg8 in living mouse liver by in vivo transfection of the genes of fluorescent protein-tagged transporters and investigated how hypernutrition affects the canalicular trafficking of these transporters. The kinetic analysis showed that lithogenic diet consumption accelerated the translocation of newly synthesized fluorescent-tagged transporters to intracellular pools in an endosomal compartment and enhanced the recruitment of these pooled gene products into the bile canalicular membrane in mouse liver. Because some ABC transporters are reported to be recruited from intracellular pools to the bile canaliculi by cyclic adenosine monophosphate (cAMP) signaling, we next evaluated the involvement of this machinery in a diet-induced event. Administration of a protein kinase A inhibitor, N-(2-{[3-(4-bromophenyl)-2-propenyl]amino}ethyl)-5-isoquinolinesulfonamide, decreased the canalicular expression of native Abcg5/Abcg8 in lithogenic diet-fed mice, and injection of a cAMP analog, dibutyryl cAMP, transiently increased their levels in standard diet-fed mice, indicating the involvement of cAMP signaling. Indeed, canalicular trafficking of the fluorescent-tagged Abcg5/Abcg8 was enhanced by dibutyryl cAMP administration. CONCLUSION: These observations suggest that diet-induced lipid loading into liver accelerates the trafficking of Abcg5/Abcg8 to the bile canalicular membrane through cAMP signaling machinery.