Analysis of the potential of human cultured nasal epithelial cell sheets to differentiate into airway epithelium.

Understanding the expected efficacy and safety of a new regenerative therapy requires analysis of the fate of the transplanted cell graft. We have shown that transplantation of autologous cultured nasal epithelial cell sheets onto the middle ear mucosa can improve middle ear aeration and hearing. However, it remains unknown whether cultured nasal epithelial cell sheets have the potential to gain mucociliary function in the environment of the middle ear because sampling cell sheets after transplantation is challenging.

Retraction notice to "Preclinical assessment of transplantable human nasal mucosal epithelial cell sheets" [Regenerative Therapy 18 (2021) 59-65].

[This retracts the article DOI: 10.1016/j.reth.

Transplantation of a human induced pluripotent stem cell-derived airway epithelial cell sheet into the middle ear of rats.

Introduction: Early postoperative regeneration of the middle ear mucosa is essential for the prevention of postoperative refractory otitis media and recurrent cholesteatoma. As a means for intractable otitis media management, we focused on human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (AECs), which have been used in upper airway mucosal regeneration and transplantation therapy. In this study, we transplanted hiPSC-derived AECs into the middle ear of immunodeficient rats.

Cell sheet transplantation prevents inflammatory adhesions: A new treatment for adhesive otitis media.

Introduction: We developed a new treatment method that combines tympanoplasty with transplantation of autologous cultured nasal mucosal epithelial cell sheets to regenerate the mucosa of patients with adhesive otitis media, which has been difficult to treat effectively. We verified whether this procedure could be performed safely and measured its therapeutic efficacy.

Methods: Autologous nasal mucosal epithelial cell sheets were manufactured at a good manufacturing practice-compliant cell processing facility using autologous nasal mucosal tissue.

Temporary Storage of the Human Nasal Tissue and Cell Sheet for Wound Repair.

Temporary storage of nasal tissues and nasal cell sheets, which entails transportation between hospitals and cell culture facilities, is an important issue in regenerative medicine. Herein, we investigated the preservation of chilled and frozen nasal tissues and expiry dates of ready-to-use nasal cell sheets. Although the cell number in preserved tissues was lower than that in fresh tissue, nasal cell sheets could be fabricated from tissues that had been refrigerated for 5 days and frozen-thawed over 5 days.

Preclinical assessment of transplantable human nasal mucosal epithelial cell sheets.

Introduction: We previously reported a new cell transplantation therapy for patients with intractable otitis media using autologous nasal mucosal epithelial cell sheets, manufactured using temperature-responsive cell culture inserts. The current study aimed to verify whether the transplantable cell sheets could be manufactured for application in clinical trials, according to standard operational procedures (SOP), in a cell processing facility (CPF).

Methods: Human nasal mucosal epithelial cells from four volunteer donors were aseptically cultured and transplantable cell sheets successfully manufactured, with reproducibility, using temperature-responsive cell culture inserts in the CPF.

ROCK inhibitor combined with Ca controls the myosin II activation and optimizes human nasal epithelial cell sheets.

The proliferation and differentiation of cultured epithelial cells may be modified by Rho-associated kinase (ROCK) inhibition and extracellular Ca concentration. However, it was not known whether a combination would influence the behavior of cultured epithelial cells through changes in the phosphorylation of non-muscle myosin light chain II (MLC). Here we show that the combination of ROCK inhibition with Ca elevation regulated the phosphorylation of MLC and improved both cell expansion and cell-cell adhesion during the culture of human nasal mucosal epithelial cell sheets.

Efficient preparation of human and mouse CD1d proteins using silkworm baculovirus expression system.

CD1d is a major histocompatibility complex (MHC) class I-like glycoprotein and binds to glycolipid antigens that are recognized by natural killer T (NKT) cells. To date, our understanding of the structural basis for glycolipid binding and receptor recognition of CD1d is still limited. Here, we established a preparation method for the ectodomain of human and mouse CD1d using a silkworm-baculovirus expression system.

A stable protocol for the fabrication of transplantable human oral mucosal epithelial cell sheets for clinical application.

Introduction: Cultured stratified epithelial cell sheets have been clinically utilized as transplantable grafts for the regeneration of epithelial tissues, such as the esophagus, cornea, skin, and intraoral cavity. These cell sheets are expected to gain widespread use as regenerative medicine products and save many patients. For this purpose, establishing and disseminating the stale protocol of fabricating the cell sheet is crucial.

Analysis of human nasal mucosal cell sheets fabricated using transported tissue and blood specimens.

Previously, we succeeded in transplanting autologous nasal mucosal cell sheets in the middle ears of 5 patients, who underwent cholesteatoma resection, which prevents recurrence of cholesteatoma in clinical settings. Current good manufacturing practice (GMP) standards for human cell cultivation requires the establishment of cell processing centers (CPC) which act as germ-free facilities. However, due to practical difficulties involved in establishing and maintaining such facilities at each individual hospital, a functional transport system is felt to be needed for the continuation of effective regenerative therapy.

Oral keratinocyte-derived exosomes regulate proliferation of fibroblasts and epithelial cells.

Extracellular vesicles (EVs), including exosomes, are small membrane-bound particles released by cells. From a therapeutic point of view, EVs can often convey similar biological function as their parent cell. Grafts originating from oral mucosa have frequently been used in regenerative medicine, and we have previously described the use of oral cell sheets to prevent stricture formation of the esophagus.

Exosomes derived from clinical-grade oral mucosal epithelial cell sheets promote wound healing.

The oral mucosa exhibits unique regenerative properties, sometimes referred to as foetal-like wound healing. Researchers from our institute have used sheets of oral mucosa epithelial cells (OMECs) for regenerative medicine applications including cornea replacement and oesophageal epithelial regeneration for stricture prevention. Here, we have isolated exosomes from clinical-grade production of OMEC sheets from healthy human donors ( = 8), aiming to evaluate the clinical potential of the exosomes to stimulate epithelial regeneration and to improve understanding of the mode-of-action of the cells.

The role of ADAM-like decysin 1 in non-eosinophilic chronic rhinosinusitis with nasal polyps.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is classified into two subtypes: eosinophilic (ECRSwNP) and non-eosinophilic (NECRSwNP). Although the inflammatory patterns of ECRSwNP have been elucidated, NECRSwNP is poorly understood.

Aims/objectives: The metalloproteinase ADAM-like decysin 1 (ADAMDEC1) has been reported to play a role in the early stages of the inflammatory response.

Oral epithelial cell sheets engraftment for esophageal strictures after endoscopic submucosal dissection of squamous cell carcinoma and airplane transportation.

Endoscopic submucosal dissection (ESD) permits en bloc removal of superficial oesophageal squamous cell carcinoma (ESCC). However, post-procedure stricture is common after ESD for widespread tumours, and multiple endoscopic balloon dilation (EBD) procedures are required. We aimed to evaluate the safety and effectiveness of endoscopic transplantation of tissue-engineered autologous oral mucosal epithelial cell sheets that had been transported by air over a distance of 1200 km in controlling postprocedural oesophageal stricture.

Cellular events and behaviors after grafting of stratified squamous epithelial cell sheet onto a hydrated collagen gel.

Autologous stratified squamous epithelial cell sheets have been successfully used to treat epithelial defects in tissues such as the cornea and the esophagus. However, the regenerative cellular events occurring in the grafted epithelial cells are unclear in the early stages of wound healing. In this study, we created an grafting model using cultured normal human epidermal keratinocyte (NHEK) sheets and a type I collagen gel to investigate the cellular processes that occur within the grafted cell sheet.

Cutting Edge: Class II-like Structural Features and Strong Receptor Binding of the Nonclassical HLA-G2 Isoform Homodimer.

HLA-G is a natural tolerogenic molecule and has the following unique features: seven isoforms (HLA-G1 to HLA-G7), formation of disulfide-linked homodimers, and β2-microglobulin (β2m)-free forms. Interestingly, individuals null for the major isoform, HLA-G1, are healthy and expressed the α2 domain-deleted isoform, HLA-G2, which presumably compensates for HLA-G1 function. However, the molecular characteristics of HLA-G2 are largely unknown.

Brush biopsy of human oral mucosal epithelial cells as a quality control of the cell source for fabrication of transplantable epithelial cell sheets for regenerative medicine.

Autologous oral mucosal epithelial cell sheets have been used for treating epithelial defects such as cornea and esophagus. The cell source of patients' oral mucosal epithelial cell sheet should be examined in normality because it has individual difference. In this study, oral mucosal epithelial cells were less invasively collected by brush biopsy from the buccal, gingival, labial, and palate mucosa of four healthy volunteer donors without anesthesia, and analyzed the keratin expressions by western blotting and the obtained results were compared with those by immunohistochemistry of each of the native tissues.

The immunosuppressive effect of domain-deleted dimer of HLA-G2 isoform in collagen-induced arthritis mice.

HLA-G is involved in maternal-fetal immune tolerance and is reported to be a natural tolerogenic molecule. Seven-spliced isoforms including dimeric and β2m-free forms have been identified. The major isoform, HLA-G1 (and its soluble type HLA-G5), binds to the inhibitory immune receptors, leukocyte immunoglobulin (Ig)-like receptor (LILR) B1 and LILRB2.

Crystal structure of extracellular domain of human lectin-like transcript 1 (LLT1), the ligand for natural killer receptor-P1A.

Emerging evidence has revealed the pivotal roles of C-type lectin-like receptors (CTLRs) in the regulation of a wide range of immune responses. Human natural killer cell receptor-P1A (NKRP1A) is one of the CTLRs and recognizes another CTLR, lectin-like transcript 1 (LLT1) on target cells to control NK, NKT and Th17 cells. The structural basis for the NKRP1A-LLT1 interaction was limitedly understood.

How to prevent contamination with during the fabrication of transplantable oral mucosal epithelial cell sheets.

We have utilized patients' own oral mucosa as a cell source for the fabrication of transplantable epithelial cell sheets to treat limbal stem cell deficiency and mucosal defects after endoscopic submucosal dissection of esophageal cancer. Because there are abundant microbiotas in the human oral cavity, the oral mucosa was sterilized and 40 μg/mL gentamicin and 0.27 μg/mL amphotericin B were added to the culture medium in our protocol.

Prevention of esophageal strictures after endoscopic submucosal dissection.

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have recently been accepted as less invasive methods for treating patients with early esophageal cancers such as squamous cell carcinoma and dysplasia of Barrett's esophagus. However, the large defects in the esophageal mucosa often cause severe esophageal strictures, which dramatically reduce the patient's quality of life. Although preventive endoscopic balloon dilatation can reduce dysphagia and the frequency of dilatation, other approaches are necessary to prevent esophageal strictures after ESD.