Rapid and chronological expression of angiogenetic genes is a major mechanism involved in cell sheet transplantation in a rat gastric ulcer model

Optimal good manufacturing practice-compliant production of dental follicle stem cell sheet and its application in Sprague-Dawley rat periodontitis

BACKGROUND

Dental follicle stem cell (DFSC) sheets demonstrate strong extracellular secretion capabilities and efficacy in periodontal regeneration. However, existing methods for producing DFSC sheets lack a comprehensive discussion on the most efficient and cost-effective approaches at the good manufacturing practice (GMP) level.

AIM

To investigate the culture condition of GMP-compliant DFSC sheets and to compare the properties of DFSC sheets and cell suspensions.

METHODS

This study explored the optimal conditions for culturing GMP-compliant DFSC sheets, focusing on four key factors: Cell passage, cell concentration, L-ascorbic acid content, and culture duration. We evaluated the characteristics of the cell sheets under varying culture conditions, including cell viability, cell count, appearance, osteogenesis, chondrogenesis, odontogenesis, aging, relative telomere length, and extracellular matrix secretion. A comparison was also made between the periodontal regeneration, osteogenesis, and paracrine capacity of cell sheets cultured under optimal conditions and those of the cell suspensions.

RESULTS

The GMP-compliant DFSC sheets cultured from passage 4 cells exhibited the highest viability (≥ 99%, P < 0.05) and optimal osteogenic differentiation capacity (optical density ≥ 0.126, P < 0.05). When cultured for 10 days, DFSC sheets demonstrated maximal expression of osteogenic, chondrogenic and periostin genes [alkaline phosphatase, Runt-related transcription factor 2, collagen type I, osteopontin, cartilage associated protein, and PERIOSTN (P < 0.001); osteocalcin (P < 0.01)]. Concurrently, they showed the lowest senescent cell count (P < 0.01) with no progression to late-stage senescence. At a seeding density of 2500 cells/cm², GMP-compliant DFSC sheets achieved better osteogenic differentiation (P < 0.01) and maximal osteogenic, chondrogenic and periostin gene expression (P < 0.001), coupled with the highest hydroxyproline secretion (P < 0.001) and moderate sulfated glycosaminoglycan production. No statistically significant difference in senescent cell count was observed compared to DFSC sheets at a seeding density of 5000 cells/cm². Supplementation with 25 μg/mL L-ascorbic acid significantly enhanced osteogenic gene expression (P < 0.001) and elevated hydroxyproline (P < 0.01) and sulfated glycosaminoglycan secretion to high ranges. Compared with the cell suspension, the cell sheet demonstrated improved osteogenic, paracrine, and periodontal regenerative capacities in Sprague-Dawley rats. The optimized DFSC sheets demonstrated significantly higher levels of vascular endothelial growth factor and angiopoietin-1 (P < 0.001) compared to DFSC suspensions, along with enhanced osteogenic induction outcomes (optical density = 0.1333 ± 0.01270 vs 0.1007 ± 0.0005774 in suspensions, P < 0.05). Following implantation into the rat periodontal defect model, micro-computed tomography analysis revealed superior bone regeneration metrics in the cell sheet group compared to both the cell suspension group and control group (percent bone volume, trabecular thickness, trabecular number), while trabecular spacing exhibited an inverse pattern.

CONCLUSION

Optimized DFSC sheets cultured under the identified conditions outperform DFSC suspensions. This study contributes to the industrial-scale production of DFSC sheets and establishes a foundation for cell therapy applications.

A first-in-human clinical study of laparoscopic autologous myoblast sheet transplantation to prevent delayed perforation after duodenal endoscopic mucosal dissection

BACKGROUND

The detection rate of superficial non-ampullary duodenal epithelial tumors (SNADETs) has recently been increasing. Large tumors may contain malignant lesions and early therapeutic intervention is recommended. Endoscopic mucosal dissection (ESD) is considered a feasible treatment modality, however, the anatomical and physiological characteristics of the duodenum create a risk of postoperative perforation after ESD.

METHODS

To explore whether myoblast sheet transplantation could prevent delayed perforation after ESD, a first-in-human (FIH) clinical trial of laparoscopic autologous myoblast sheet transplantation after duodenal ESD was launched. Autologous myoblast sheets fabricated from muscle tissue obtained seven weeks before ESD were transplanted laparoscopically onto the serous side of the ESD. The primary endpoints were the onset of peritonitis due to delayed perforation within three days after surgery and all adverse events during the follow-up period.

RESULTS

Three patients with SNADETs ≥ 20 mm in size underwent transplantation of a myoblast sheet onto the serous side of the duodenum after ESD. In case 1, The patient's postoperative course was uneventful. Endoscopy and abdominal computed tomography revealed no signs of delayed perforation. Despite incomplete mucosal closure in case 2, and multiple micro perforations during ESD in case 3, cell sheet transplantation could prevent the postoperative massive perforation after ESD, and endoscopy on day 49 after transplantation revealed no stenosis.

CONCLUSIONS

This clinical trial showed the safety, efficacy, and procedural operability of this novel regenerative medicine approach involving transplanting an autologous myoblast sheet laparoscopically onto the serosa after ESD in cases with a high risk of delayed perforation. This result indicates the potential application of cell sheet medicine in treating various abdominal organs and conditions with minimal invasiveness in the future.

TRIAL REGISTRATION

jRCT, jRCT2073210094. Registered November 8 2021, https://jrct.niph.go.jp/latest-detail/jRCT2073210094 .

Periostin plays a key role in maintaining the osteogenic abilities of dental follicle stem cells in the inflammatory microenvironment

OBJECTIVE

This study aimed to explore the effect of periostin in the osteogenic abilities of dental follicle stem cells (DFSCs) and DFSC sheets in the inflammatory microenvironment.

DESIGN

DFSCs were isolated from dental follicles and identified. A lentiviral vector was used to knock down periostin in DFSCs. 250 ng/ml lipopolysaccharide from Porphyromonas gingivalis (P.g-LPS) was used to construct the inflammatory microenvironment. Osteogenic differentiation was evaluated by alizarin red staining, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot. The formation of extracellular matrix was assessed by qRT-PCR and immunofluorescence. The expressions of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) were measured by western blot.

RESULTS

Knockdown of periostin inhibited osteogenic differentiation and promoted adipogenic differentiation of DFSCs. In an inflammatory microenvironment, knockdown of periostin attenuated the proliferation and osteogenic differentiation of DFSCs. Knockdown of periostin inhibited the formation of extracellular matrix collagen I (COL-I), fibronectin, and laminin in DFSC sheets, but did not affect the expression of osteogenesis-related markers alkaline phosphatase (ALP) and osteocalcin (OCN). In the inflammatory microenvironment, knocking down periostin inhibited the expression of OCN and OPG in DFSC sheets, and promoted the expression of RANKL.

CONCLUSION

Periostin played a key role in maintaining the osteogenic abilities of DFSCs and DFSC sheets in the inflammatory microenvironment and might be an important molecule in the process of DFSCs coping with inflammatory microenvironment and promoting periodontal tissues regeneration.