Fabry disease (FD) is a congenital metabolic disorder characterized by the accumulation of globotriaosylceramide (Gb3) due to deficient alpha-galactosidase A (GLA) activity. Although the presence of urinary mulberry bodies (uMBs) in FD is well documented, their precise origins and molecular composition remain poorly understood. In the present study, we performed comprehensive morphological, molecular, pathological, and structural analyses of uMBs. Our results revealed that uMBs are dynamic structures that exhibit substantial structural plasticity in response to fluid flow. We demonstrated that uMBs originate from podocytes rather than renal tubular cells and are primarily composed of lysosome-derived structures. Furthermore, we identified glomerular basement membrane components within these podocyte-derived uMBs, suggesting a complex shedding process in the urine. Three-dimensional reconstruction with confocal laser scanning microscopy was used to successfully visualize the complex internal architectures of these structures. Experiments using GLA knockout cells suggested a potential association between Gb3 accumulation and the induction of cell death via the JNK signaling pathway. These findings provide novel insights into the structural characteristics and pathological relevance of uMBs in the pathogenesis of FD nephropathy.

Currently, no drugs directly treat liver fibrosis. Previously, we have shown that treatment with miR-29a-3p improved liver fibrosis in a mouse model. To investigate the effectiveness of nucleic acid therapy at a lower dose, a modified nucleic acid was prepared based on miR-29a-3p. The original microRNA was changed to an RNA-DNA hybrid structure: the 20 position of the RNA was modified with a fluorine base, and locked nucleic acid and phosphorothioate were crosslinked (hereafter called modified nucleic acid). In a mouse model of chronic liver disease treated with carbon tetrachloride (CCl4), the inhibitory effect on liver fibrosis was evaluated with oral administration of the modified nucleic acid. The modified nucleic acid was detected in the liver and gastrointestinal tract within 15 min of oral administration. After 5 weeks of stimulation with CCl4, oral administration of the modified nucleic acid for 2 weeks improved liver fibrosis; CCl4 stimulation was continued during this period as well. This treatment also suppressed the worsening of liver fibrosis. We developed a method to improve liver fibrosis orally using nuclease-resistant nucleic acids without using a drug delivery system. This method may be used as a new treatment for inhibiting the progression of liver fibrosis.

DICER1 syndrome is a tumor predisposition syndrome caused by familial genetic mutations in DICER1. Pathogenic variants of DICER1 have been discovered in many rare cancers, including cystic liver tumors. However, the molecular mechanisms underlying liver lesions induced by these variants remain unclear. In the present study, we sought to gain a better understanding of the pathogenesis of these variants by generating a mouse model of liver-specific DICER1 syndrome. The mouse model developed bile duct hyperplasia with fibrosis, similar to congenital hepatic fibrosis, as well as cystic liver tumors resembling those in Caroli's syndrome, intrahepatic cholangiocarcinoma, and hepatocellular carcinoma. Interestingly, the mouse model of DICER1 syndrome showed abnormal formation of primary cilia in the bile duct epithelium, which is a known cause of bile duct hyperplasia and cyst formation. These results indicated that DICER1 mutations contribute to cystic liver tumors by inducing defective primary cilia. The mouse model generated in this study will be useful for elucidating the potential mechanisms of tumorigenesis induced by DICER1 variants and for obtaining a comprehensive understanding of DICER1 syndrome. © 2024 The Pathological Society of Great Britain and Ireland.

Introduction: Mesenchymal stem cells (MSCs) are promising therapeutic tools in regenerative medicine. In particularly adipose tissue derived MSC (AMSC) has powerful potential for the therapeutics of rheumatoid arthritis (RA) because these cells can control immune balance. RA systemically occurs autoimmune disease. Interestingly, IL-1 receptor antagonist deficient (IL-1ra−/−) mice induce inflammation in joints like RA. In RA therapy, although AMSC improves the inflammation activity, it is little known to play roles of extracellular microvesicles (EV) for improvement of RA. To clarify the MSC-derived EVs are involved amelioration mechanisms for RA by themselves, we examined the functional effects of development for RA by AMSC-EVs. Methods: We isolated AMSCs derived mice adipose tissue and purified EVs from the culture supernatant of AMSCs. To examine whether EVs can improve RA, we administrated EVs or AMSCs to IL-1ra knockout mice as RA model mice. We analyzed EVs-included factor by western blot methods and RA improvement effect by ELISA. Results: In this study, we showed that the swellings of joints on mice in wild type AMSC and that in AMSC-EVs decreased than that in IL-1ra−/− mice-AMSC-EVs and in none-treated. We detected IL-1ra expression in AMSC-EVs in wild type mice but not that in IL-1ra−/− mice. Proinflammatory cytokine expression changes in mice showed in AMSCs and AMSC-EVs, but no apparent differences cytokine expressions were detected in IL-1ra−/− mice. Conclusions: In this study, we concluded that MSCs might improve RA by the transferring of factors such as IL-1ra, which are included their MSC derived- EVs.

Triple negative breast cancer (TNBC) is responsible for significant number of breast cancer-associated deaths because of lacking of successful molecular-targeted therapy. To explore a therapeutic target for TNBC, we performed a siRNA-mediated knockdown screening and identified Polo-like kinase 1 (PLK1) as a potential therapeutic target for TNBC. Knockdown of PLK1 as well as a small compound inhibitor for PLK1, BI-2536, induced G2/M arrest and created polyploid cell population, shown by increased DNA content and nuclear size. Inhibition of PLK1 eventually triggered apoptosis in multiple TNBC cell lines. In addition, we confirmed that PLK1 was significantly overexpressed in the tissues from TNBC patients compared with the tissues of normal mammary glands and benign breast tumors. Our data indicated that PLK1 plays a pivotal role in the regulation of mitosis of TNBC cells. Although future in vivo studies are warranted, targeting PLK1 by a selective inhibitor such as BI-2536 can be an attractive molecular-targeted therapy for TNBC.

RNA interference (RNAi) has become a powerful tool for suppressing gene expression in vitro and in vivo. A great deal of evidence has demonstrated the potential for the use of synthetic small interfering RNAs (siRNAs) as therapeutic agents. However, the application of siRNA to clinical medicine is still limited, mainly due to sequence-independent suppression of angiogenesis mediated by Toll-like receptor 3 (TLR3). Here, we describe novel types of synthetic RNA, named nkRNA and PnkRNA, that exhibit sequence-specific gene silencing through RNAi without activating TLRs or RIG-I-like receptor signaling. In addition, we confirmed the therapeutic effect for the novel types of RNA in an animal model of age-related macular degeneration (AMD) without retinal degeneration. These data indicate that nkRNA and PnkRNA are of great potential utility as therapies against blinding choroidal neovascularization due to AMD.

Despite the therapeutic potential of nucleic acid drugs, their clinical application has been limited in part by a lack of appropriate delivery systems. Exosomes or microvesicles are small endosomally derived vesicles that are secreted by a variety of cell types and tissues. Here, we show that exosomes can efficiently deliver microRNA (miRNA) to epidermal growth factor receptor (EGFR)-expressing breast cancer cells. Targeting was achieved by engineering the donor cells to express the transmembrane domain of platelet-derived growth factor receptor fused to the GE11 peptide. Intravenously injected exosomes delivered let-7a miRNA to EGFR-expressing xenograft breast cancer tissue in RAG2(-/-) mice. Our results suggest that exosomes can be used therapeutically to target EGFR-expressing cancerous tissues with nucleic acid drugs.

A variety of cells release membrane vesicles, such as exosomes and microvesicles (MVs), that are thought to play key roles in cell–cell communication, antigen presentation, and the spread of infectious agents throughout the body. There have been considerable efforts to use MVs as diagnostic or prognostic markers because their composition is reflective of minor physiological changes. Furthermore, recent studies demonstrate that MVs derived from infected cells and tumors contribute to disease pathogenesis. This review presents an overview of the potential roles of MVs with respect to clinical diagnosis and disease pathogenesis.

Regarding the process of uveitis development, many past studies have used the experimental autoimmune uveoretinitis (EAU) and other animal models to observe histologically the infiltration of inflammatory cells and the process of lesion progression. However, no detailed study of the process of clearance of infiltrated inflammatory cells from the eye has been reported. The purpose of this study was to investigate the process of clearance of polymorphonuclear leukocytes (PMNs) using an experimental hypopyon model. PMNs obtained from ascites of SD rat were injected into the anterior chamber of SD rats. The process of PMNs clearance was evaluated by serial photography and 3D optical coherence tomography (3D-OCT), and histological changes were observed simultaneously. The hypopyon heights regressed from 1.04 ± 0.06 mm at 1 h (day0) to 0.45 ± 0.07 mm at day1, and 0 mm at day3 after PMNs injection. When the hypopyon heights at the three time points were compared, significant differences were found between groups (P < 0.05). The hypopyon volumes also decreased from 1.46 ± 0.07 mm3 at 1 h to 1.16 ± 0.09 mm3 at 2 h, and 0.83 ± 0.04 mm3 at 3 h after PMN injection. When the hypopyon volumes at the three time points were compared, significant differences were found between groups (P < 0.05). Light micrographs of inferior segment of the eyeball revealed dense PMNs in the chamber angle at 1 h after PMNs injection and many PMNs in the iris stroma and vessels, as well as at the episcleral and subconjunctival tissues around limbus at 3 h and day1 after PMNs injection. Light micrographs of superior segment of the eyeball at 3 h after injection revealed PMNs in the episcleral and subconjunctival vessels. Electron micrographs of inferior segment of the eyeball at 3 h after PMNs injection revealed dense PMNs with slightly condensed nuclei in the anterior chamber, as well as in the iris stroma and vessels. In conclusion, in the experimental hypopyon model, PMNs injected into the anterior chamber were cleared from the eye mainly through the iris stroma and vessels, as well as the episcleral and subconjunctival tissues around limbus.

The fusion oncoproteins, TLS-CHOP and EWS-CHOP, are characteristic markers for myxoid and round cell liposarcomas (MLS/RCLS). Especially, the peptide sequence of 26 amino acids corresponding to the normally untranslated CHOP exon 2 and parts of exon 3 (5-UTR) is a unique structure for these chimeric proteins. In this report, we have generated monoclonal antibodies against the unique peptide sequence of TLS/EWS-CHOP oncoproteins. These antibodies reacted with TLS-CHOP fusion protein, but not reacted with normal TLS and CHOP proteins by Western blot analysis. In addition, one of the antibodies also recognized the chimeric oncoprotein in archival paraffin-embedded tissue samples of MLS/RCLS. The oncoprotein was detectable by the antibody even in the paraffin-embedded tissue samples whose mRNAs were too degraded to be detected by a nested reverse transcription-polymerase chain reaction-based assay. Thus, the molecular assay using the novel antibody is expected to be one of the most sensitive diagnostic assays for MLS/RCLS.

We report a tumor in an 80-year-old man that was difficult to distinguish from other tumors, i.e., small cell carcinoma of the lung, PNET/Ewing tumor, malignant lymphoma, or malignant melanoma (amelanotic), and which was finally identified as cutaneous neuroendocrine carcinoma using immunohistochemical and ultrastructural methods. Autopsy did not show any tumors in the lungs, excluding the possibility of small cell carcinoma of the lung. Immunohistochemistry tests gave negative results for LCA, UCHL-1, CD3, and CD20, thereby excluding malignant lymphoma, and the negative results for S-100 protein and HMB-45 ruled out malignant melanoma. The possibility of PNET/Ewing sarcoma was also excluded because of negativity for CD99. In addition, the ultramicrostructure showed intercellular junctional complexes and neuroendocrine granules, indicating that the tumor had characteristics of both epithelial and neuroendocrine tissues. We therefore diagnosed the primary carcinoma of the skin as cutaneous neuroendocrine carcinoma.