Vitronectin regulates osteoclastogenesis and bone remodeling in a mouse model of osteoporosis.

Vitronectin (VN) is an extracellular matrix protein with a crucial role in regulating bone remodeling. In this study, we aimed to investigate the effect of VN deficiency in a mouse model of osteoporosis induced by ovariectomy (OVX). The findings revealed that the absence of VN led to an increase in the activity of tartrate-resistant acid phosphatase (TRAP), a marker for osteoclasts, in the plasma of OVX-operated mice. TRAP staining further demonstrated that VN deficiency resulted in a higher number of osteoclasts within the femurs of OVX-operated mice. X-ray micro-computed tomography analysis of the femurs in OVX-operated mice indicated that VN deficiency significantly suppressed the OVX-induced increase of marrow area and total volume of bone. Additionally, we assessed structural model index (SMI) and degree of anisotropy (DA) as indices of osteoporosis. The results showed that VN deficiency effectively attenuated the OVX-induced increase in SMI and DA among OVX-operated mice. In summary, our study demonstrates the vital role of VN in regulating osteoclastogenesis and bone remodeling in the mouse model of osteoporosis.

Craniofacial bone anomalies related to cholesterol synthesis defects.

DHCR7 and SC5D are enzymes crucial for cholesterol biosynthesis, and mutations in their genes are associated with developmental disorders, which are characterized by craniofacial deformities. We have recently reported that a loss of either Dhcr7 or Sc5d results in a failure in osteoblast differentiation. However, it remains unclear to what extent a loss of function in either DHCR7 or SC5D affects craniofacial skeletal formation. Here, using micro computed tomography (µCT), we found that the bone phenotype differs in Dhcr7-/- and Sc5d-/- mice in a location-specific fashion. For instance, in Sc5d-/- mice, although craniofacial bones were overall affected, some bone segments, such as the anterior part of the premaxilla, the anterior-posterior length of the frontal bone, and the main body of the mandible, did not present significant differences compared to WT controls. By contrast, in Dhcr7-/- mice, while craniofacial bones were not much affected, the frontal bone was larger in width and volume, and the maxilla and palatine bone were hypoplastic, compared to WT controls. Interestingly the mandible in Dhcr7-/- mice was mainly affected at the condylar region, not the body. Thus, these results help us understand which bones and how greatly they are affected by cholesterol metabolism aberrations in Dhcr7-/- and Sc5d-/- mice.

Immune checkpoint inhibitor-associated colitis in unresectable hepatocellular carcinoma: two cases of early onset after treatment with durvalumab plus tremelimumab.

The HIMALAYA trial is the first chemotherapeutic trial to demonstrate the efficacy of combined immune checkpoint inhibitors (ICIs) for unresectable hepatocellular carcinoma (u-HCC). The STRIDE regimen used in this trial consists of a cytotoxic T-lymphocyte antigen-4 (CTLA-4) inhibitor and programmed cell death ligand 1 (PD-L1) inhibitor. Herein, we report two cases of ICI-colitis that occurred immediately after the initiation of the STRIDE regimen for u-HCC. A 73-year-old man and 75-year-old man with u-HCC were treated with the STRIDE regimen. Both patients developed grade 3 diarrhea (Common Terminology Criteria for Adverse Events, ver. 5.0) within 10 days of treatment initiation. Colonoscopy revealed aphthous erosions and erythema extending from the terminal ileum to the rectum in one case, while the other showed aphthous ulcers in the terminal ileum and shallow ulcers in the colorectum. Histopathological examination of a biopsy specimen revealed epithelial cell apoptosis and neutrophil infiltration bodies, consistent with ICI-colitis. Prednisolone (0.5 mg/kg) was effective in both patients. Our experience suggests the need for both careful monitoring and early endoscopic examination of ICI colitis in patients with unresectable HCC treated with the STRIDE regimen.

Single-cell multiomics decodes regulatory programs for mouse secondary palate development.

Perturbations in gene regulation during palatogenesis can lead to cleft palate, which is among the most common congenital birth defects. Here, we perform single-cell multiome sequencing and profile chromatin accessibility and gene expression simultaneously within the same cells (n = 36,154) isolated from mouse secondary palate across embryonic days (E) 12.5, E13.5, E14.0, and E14.5. We construct five trajectories representing continuous differentiation of cranial neural crest-derived multipotent cells into distinct lineages. By linking open chromatin signals to gene expression changes, we characterize the underlying lineage-determining transcription factors. In silico perturbation analysis identifies transcription factors SHOX2 and MEOX2 as important regulators of the development of the anterior and posterior palate, respectively. In conclusion, our study charts epigenetic and transcriptional dynamics in palatogenesis, serving as a valuable resource for further cleft palate research.

Seroprevalence and incidence of hepatitis E virus infection in the general population of Iwate prefecture, Japan: A retrospective cohort study.

AIM: Hepatitis E virus (HEV) causes subclinical or acute self-limiting hepatitis. We surveyed the current seroprevalence and incidence of HEV infection among the general population in Iwate Prefecture, Japan, where the endemic infection is presumed to be low. METHODS: Between 2014 and 2016, we recruited individuals from Iwate Prefecture, Japan, who visited a general medical work-up program. Serum anti-HEV antibody and HEV RNA were measured twice, with an interval of 2 years. Anti-HEV antibody was measured with enzyme-linked immunosorbent assay and HEV RNA with reverse transcription-polymerase chain reaction. RESULTS: Study participants comprised 1284 Japanese (650 men and 634 women) with age ranging 20-89 years. A total of 90 participants were found to be positive for anti-HEV immunoglobulin G on the first visit, with a prevalence of 7.0% (95% confidence interval [CI] 5.6%-8.4%). Seroprevalence was higher in men than in women (10.1% vs. 3.7%, p < 0.001), and in those aged in their 50s-80s than in those aged in their 20s-40s (p = 0.006). Positive seroconversion indicating new HEV infection was found in seven of 1194 seronegative participants (0.59%; 95% CI 0.15%-1.0%), indicating the incidence of HEV infection to be 272 per 100 000 person-years (95% CI 109-561). CONCLUSIONS: Our observations suggest that the incidence of HEV infection is high and that it is a leading cause of hepatitis virus infection in Iwate Prefecture, Japan.

Loss of Sc5d results in micrognathia due to a failure in osteoblast differentiation.

INTRODUCTION: Mutations in genes related to cholesterol metabolism, or maternal diet and health status, affect craniofacial bone formation. However, the precise role of intracellular cholesterol metabolism in craniofacial bone development remains unclear. OBJECTIVE: The aim of this study is to determine how cholesterol metabolism aberrations affect craniofacial bone development. METHODS: Mice with a deficiency in Sc5d, which encodes an enzyme involved in cholesterol synthesis, were analyzed with histology, micro computed tomography (microCT), and cellular and molecular biological methods. RESULTS: Sc5d null mice exhibited mandible hypoplasia resulting from defects in osteoblast differentiation. The activation of the hedgehog and WNT/ß-catenin signaling pathways, which induce expression of osteogenic genes Col1a1 and Spp1, was compromised in the mandible of Sc5d null mice due to a failure in the formation of the primary cilium, a cell surface structure that senses extracellular cues. Treatments with an inducer of hedgehog or WNT/ß-catenin signaling or with simvastatin, a drug that restores abnormal cholesterol production, partially rescued the defects in osteoblast differentiation seen in Sc5d mutant cells. CONCLUSION: Our results indicate that loss of Sc5d results in mandibular hypoplasia through defective primary cilia-mediated hedgehog and WNT/ß-catenin signaling pathways.

A Case of Autoimmune Hepatitis Complicated by Undiagnosed Factor VII Deficiency: A Pitfall of Coagulopathy.

Prothrombin time (PT) is a key parameter for assessing the severity of liver disease. We present the case of a 37-year-old woman with severe acute liver injury due to autoimmune hepatitis. Although prednisolone drastically improved her hepatocyte function, her PT did not recover to the reference range. A review of her medical records revealed that the patient had normal transaminase levels and prolonged PT 2 years previously. Further examinations of her coagulopathy revealed that she had low factor VII activity, suggesting a diagnosis of factor VII deficiency. Our experience suggests that altered coagulopathy should be considered in cases of liver injury with an extraordinary PT.

Coincidental items in the definition of metabolic dysfunction-associated fatty liver are useful in identifying patients having significant fibrosis with fatty liver.

AIM: We aimed to establish a method that will identify patients at a high risk for progressive phenotype of fatty liver. METHODS: Patients with fatty liver who underwent liver biopsy between July 2008 and November 2019 were included as cohort 1, and those who underwent abdominal ultrasound screening examination by general physicians between August 2020 and May 2022 served as cohort 2. According to the definition of metabolic dysfunction-associated fatty liver (MAFLD), the subjects were classified by body mass index of ≥23, diabetes mellitus, and coexistence of two or more metabolic risk items. The progressive phenotype of MAFLD is defined by significant fibrosis complicated with either nonalcoholic fatty liver disease activity score ≥4 (BpMAFLD) or steatosis grade ≥2 by ultrasound examination (UpMAFLD). RESULTS: One hundred sixty-eight patients and 233 patients were enrolled in cohorts 1 and 2, respectively. In cohort 1, the prevalence of BpMAFLD was 0% in patients without a complicating factor (n = 10), 13% in those with one complicating factor (n = 67), 32% in those with two (n = 73), and 44% in those with all three complicating factors (n = 36). A logistic regression analysis revealed that factors in the MAFLD definition were significantly associated with BpMAFLD. In cohort 2, a criterion of two or more positive MAFLD definitions was found to have a 97.4% negative predictive value for the diagnosis of UpMAFLD. CONCLUSION: Patients with two or more complicating factors in the MAFLD definition should have further evaluation for liver fibrosis.

Circulating Cell-Free DNA as a Biomarker for Prognosis and Response to Systemic Therapy in Patients with Unresectable Hepatocellular Carcinoma.

INTRODUCTION: Systemic therapy provides clinical benefits to a subset of patients with advanced unresectable hepatocellular carcinoma (HCC). However, few biomarkers are available for predicting prognosis and treatment response in patients with advanced HCC undergoing treatment with systemic therapies. This study aimed to examine whether circulating cell-free DNA (cfDNA) containing circulating tumor DNA can act as a therapeutic response and prognostic biomarker in patients with advanced HCC. METHODS: We analyzed longitudinally collected plasma cfDNA of patients with advanced HCC who were naïve to systemic therapy, and assessed their prognostic and predictive values to determine treatment responses. RESULTS: cfDNA concentration positively correlated with entire tumor volume on computed tomography before (p = 0.0231) and at the end (p < 0.0001) of the first-line systemic therapy. The overall survival rate was higher in patients with cfDNA concentrations lower than the median cfDNA level at baseline compared to patients with higher cfDNA concentrations (hazard ratio, 0.2765; 95% confidence interval, 0.08-0.81; p = 0.0197). The ratio of cfDNA at 4 weeks to that at baseline was predictive of radiographic disease response. In patients with progressive disease, cfDNA concentration at 4 weeks increased significantly (p = 0.0245), whereas the concentration remained unchanged in patients with other disease courses (p = 0.9375). CONCLUSION: The baseline plasma cfDNA concentration can be used as a prognostic biomarker in patients with advanced HCC. cfDNA kinetics may also predict the tumor response to therapy and disease progression.

Current elimination status of hepatitis C virus-infected maintenance hemodialysis patients in Iwate Prefecture, Japan.

INTRODUCTION: The aim is to clarify the hepatitis C virus (HCV) status of hemodialysis (HD) patients and patient management after HCV elimination. METHODS: Questionnaire survey was conducted in Iwate prefecture, Japan from 2016 to 2021. RESULTS: Patients underwent HD was 2944, including 132 anti-HCV antibody-positive patients, with 91 HCV RNA-positive patients. Of the 91 HCV RNA-positive patients, 51 received antiviral treatment. Sustained virological response (SVR) rate was 94%. The patients treated with direct antiviral agents had significantly lower mortality rate than the untreated patients, and no liver-related deaths occurred in patients who achieved SVR or in HCV RNA-negative patients. The HCV RNA-positive prevalence was finally 0.79%. Approximately 40% of the facilities had dedicated beds and dialysis-related items for patients who achieved an SVR. CONCLUSION: To eliminate HCV in HD facilities, it is necessary to promote HCV RNA testing for anti-HCV antibody-positive patients and to provide antiviral treatment for HCV RNA-positive patients. Additionally, collaboration among hepatologists and HD specialists are essential.

MicroRNAs and Gene Regulatory Networks Related to Cleft Lip and Palate.

Cleft lip and palate is one of the most common congenital birth defects and has a complex etiology. Either genetic or environmental factors, or both, are involved at various degrees, and the type and severity of clefts vary. One of the longstanding questions is how environmental factors lead to craniofacial developmental anomalies. Recent studies highlight non-coding RNAs as potential epigenetic regulators in cleft lip and palate. In this review, we will discuss microRNAs, a type of small non-coding RNAs that can simultaneously regulate expression of many downstream target genes, as a causative mechanism of cleft lip and palate in humans and mice.

Impact of SARS-CoV-2 exposure history on the T cell and IgG response.

Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposures, from infection or vaccination, can potently boost spike antibody responses. Less is known about the impact of repeated exposures on T cell responses. Here, we compare the prevalence and frequency of peripheral SARS-CoV-2-specific T cell and immunoglobulin G (IgG) responses in 190 individuals with complex SARS-CoV-2 exposure histories. As expected, an increasing number of SARS-CoV-2 spike exposures significantly enhances the magnitude of IgG responses, while repeated exposures improve the number of T cell responders but have less impact on SARS-CoV-2 spike-specific T cell frequencies in the circulation. Moreover, we find that the number and nature of exposures (rather than the order of infection and vaccination) shape the spike immune response, with spike-specific CD4 T cells displaying a greater polyfunctional potential following hybrid immunity compared with vaccination only. Characterizing adaptive immunity from an evolving viral and immunological landscape may inform vaccine strategies to elicit optimal immunity as the pandemic progress.

Tailored synthesis of molecularly thin platinum nanosheets using designed 2D surfactant solids.

The assembly of the surfactants has been utilized as unique templates for the controlled synthesis of metal nanosheets. However, current strategies for metal nanosheets have mainly focused on the liquid-phase surfactant assembly. Herein, we found the solid-state surfactants as designable crystals suitable for nanostructural control and proposed a novel synthetic route for molecularly thin Pt metal nanosheets using solid surfactant crystals as a precursor. The 2D surfactant crystals containing planarly arranged Pt complexes were prepared, and the subsequent UV-ozone treatment and reduction process allowed us to obtain Pt metal nanosheets. Pt metal nanosheets had a distinct morphology with various thicknesses (from 1.5 nm to 3.0 nm), characteristic of 2D surfactant crystals.

Impaired GATE16-mediated exocytosis in exocrine tissues causes Sjögren's syndrome-like exocrinopathy.

Sjögren's syndrome (SjS) is a chronic autoimmune disease characterized by immune cell infiltration of the exocrine glands, mainly the salivary and lacrimal glands. Despite recent advances in the clinical and mechanistic characterization of the disease, its etiology remains largely unknown. Here, we report that mice with a deficiency for either Atg7 or Atg3, which are enzymes involved in the ubiquitin modification pathway, in the salivary glands exhibit a SjS-like phenotype, characterized by immune cell infiltration with autoantibody detection, acinar cell death, and dry mouth. Prior to the onset of the SjS-like phenotype in these null mice, we detected an accumulation of secretory vesicles in the acinar cells of the salivary glands and found that GATE16, an uncharacterized autophagy-related molecule activated by ATG7 (E1-like enzyme) and ATG3 (E2-like enzyme), was highly expressed in these cells. Notably, GATE16 was activated by isoproterenol, an exocytosis inducer, and localized on the secretory vesicles in the acinar cells of the salivary glands. Failure to activate GATE16 was correlated with exocytosis defects in the acinar cells of the salivary glands in Atg7 and Atg3 cKO mice. Taken together, our results show that GATE16 activation regulated by the autophagic machinery is crucial for exocytosis and that defects in this pathway cause SjS.

Micro-computed tomography assessment of bone structure in aging mice.

High-resolution computed tomography (CT) is widely used to assess bone structure under physiological and pathological conditions. Although the analytic protocols and parameters for micro-CT (µCT) analyses in mice are standardized for long bones, vertebrae, and the palms in aging mice, they have not yet been established for craniofacial bones. In this study, we conducted a morphometric assessment of craniofacial bones, in comparison with long bones, in aging mice. Although age-related changes were observed in the microarchitecture of the femur, tibia, vertebra, and basisphenoid bone, and were more pronounced in females than in males, the microarchitecture of both the interparietal bone and body of the mandible, which develop by intramembranous ossification, was less affected by age and sex. By contrast, the condyle of the mandible was more affected by aging in males compared to females. Taken together, our results indicate that mouse craniofacial bones are uniquely affected by age and sex.

Crucial Roles of microRNA-16-5p and microRNA-27b-3p in Ameloblast Differentiation Through Regulation of Genes Associated With Amelogenesis Imperfecta.

Amelogenesis imperfecta is a congenital disorder within a heterogeneous group of conditions characterized by enamel hypoplasia. Patients suffer from early tooth loss, social embarrassment, eating difficulties, and pain due to an abnormally thin, soft, fragile, and discolored enamel with poor aesthetics and functionality. The etiology of amelogenesis imperfecta is complicated by genetic interactions. To identify mouse amelogenesis imperfecta-related genes (mAIGenes) and their respective phenotypes, we conducted a systematic literature review and database search and found and curated 70 mAIGenes across all of the databases. Our pathway enrichment analysis indicated that these genes were enriched in tooth development-associated pathways, forming four distinct groups. To explore how these genes are regulated and affect the phenotype, we predicted microRNA (miRNA)-gene interaction pairs using our bioinformatics pipeline. Our miRNA regulatory network analysis pinpointed that miR-16-5p, miR-27b-3p, and miR-23a/b-3p were hub miRNAs. The function of these hub miRNAs was evaluated through ameloblast differentiation assays with/without the candidate miRNA mimics using cultured mouse ameloblast cells. Our results revealed that overexpression of miR-16-5p and miR-27b-3p, but not miR-23a/b-3p, significantly inhibited ameloblast differentiation through regulation of mAIGenes. Thus, our study shows that miR-16-5p and miR-27b-3p are candidate pathogenic miRNAs for amelogenesis imperfecta.

Suppression of microRNA 124-3p and microRNA 340-5p ameliorates retinoic acid-induced cleft palate in mice.

The etiology of cleft lip with or without cleft palate (CL/P), a common congenital birth defect, is complex, with genetic and epigenetic, as well as environmental, contributing factors. Recent studies suggest that fetal development is affected by maternal conditions through microRNAs (miRNAs), a group of short noncoding RNAs. Here, we show that miR-129-5p and miR-340-5p suppress cell proliferation in both primary mouse embryonic palatal mesenchymal cells and O9-1 cells, a neural crest cell line, through the regulation of Sox5 and Trp53 by miR-129-5p, and the regulation of Chd7, Fign and Tgfbr1 by miR-340-5p. Notably, miR-340-5p, but not miR-129-5p, was upregulated following all-trans retinoic acid (atRA; tretinoin) administration, and a miR-340-5p inhibitor rescued the cleft palate (CP) phenotype in 47% of atRA-induced CP mice. We have previously reported that a miR-124-3p inhibitor can also partially rescue the CP phenotype in atRA-induced CP mouse model. In this study, we found that a cocktail of miR-124-3p and miR-340-5p inhibitors rescued atRA-induced CP with almost complete penetrance. Taken together, our results suggest that normalization of pathological miRNA expression can be a preventive intervention for CP.

T cell responses to SARS-CoV-2 spike cross-recognize Omicron.

The SARS-CoV-2 Omicron variant (B.1.1.529) has multiple spike protein mutations1,2 that contribute to viral escape from antibody neutralization3-6 and reduce vaccine protection from infection7,8. The extent to which other components of the adaptive response such as T cells may still target Omicron and contribute to protection from severe outcomes is unknown. Here we assessed the ability of T cells to react to Omicron spike protein in participants who were vaccinated with Ad26.CoV2.S or BNT162b2, or unvaccinated convalescent COVID-19 patients (n = 70). Between 70% and 80% of the CD4+ and CD8+ T cell response to spike was maintained across study groups. Moreover, the magnitude of Omicron cross-reactive T cells was similar for Beta (B.1.351) and Delta (B.1.617.2) variants, despite Omicron harbouring considerably more mutations. In patients who were hospitalized with Omicron infections (n = 19), there were comparable T cell responses to ancestral spike, nucleocapsid and membrane proteins to those in patients hospitalized in previous waves dominated by the ancestral, Beta or Delta variants (n = 49). Thus, despite extensive mutations and reduced susceptibility to neutralizing antibodies of Omicron, the majority of T cell responses induced by vaccination or infection cross-recognize the variant. It remains to be determined whether well-preserved T cell immunity to Omicron contributes to protection from severe COVID-19 and is linked to early clinical observations from South Africa and elsewhere9-12.

4PBA reduces growth deficiency in osteogenesis imperfecta by enhancing transition of hypertrophic chondrocytes to osteoblasts.

Short stature is a major skeletal phenotype in osteogenesis imperfecta (OI), a genetic disorder mainly caused by mutations in genes encoding type I collagen. However, the underlying mechanism is poorly understood, and no effective treatment is available. In OI mice that carry a G610C mutation in COL1A2, we previously found that mature hypertrophic chondrocytes (HCs) are exposed to cell stress due to accumulation of misfolded mutant type I procollagen in the endoplasmic reticulum (ER). By fate mapping analysis of HCs in G610C OI mice, we found that HCs stagnate in the growth plate, inhibiting translocation of HC descendants to the trabecular area and their differentiation to osteoblasts. Treatment with 4-phenylbutyric acid (4PBA), a chemical chaperone, restored HC ER structure and rescued this inhibition, resulting in enhanced longitudinal bone growth in G610C OI mice. Interestingly, the effects of 4PBA on ER dilation were limited in osteoblasts, and the bone fragility was not ameliorated. These results highlight the importance of targeting HCs to treat growth deficiency in OI. Our findings demonstrate that HC dysfunction induced by ER disruption plays a critical role in the pathogenesis of OI growth deficiency, which lays the foundation for developing new therapies for OI.