The regulatory sciences for stem cell-based medicinal products

How to establish infrastructures to achieve more efficient regenerative medicine?

The field of regenerative medicine (RM) as an innovative technology has the ability to affect the healthcare system. It develops a variety of techniques through stem cell biology, genetics, bioengineering, biomaterial science, and tissue engineering to replace or restore the role of lost, disabled, or aging cells in the human body. However, the field's proficiency has still been underwhelming at the clinical trial level. This could be due to the innovation of such technologies, as well as their incredible nature. Therefore, managing the infrastructure framework for the safe and efficient application of the aforementioned field of science would help in the process of progress. In this context, the current review focuses on how to establish infrastructures for more effective RM.

Individual heterogeneity screened umbilical cord-derived mesenchymal stromal cells with high Treg promotion demonstrate improved recovery of mouse liver fibrosis

Background

To investigate the heterogeneities of human umbilical cord mesenchymal stromal cells (HUCMSCs) derived from different donors and their therapeutic variations when applied to mouse liver fibrosis model.

Methods

The characteristics of HUCMSCs derived from multiple donors were comprehensively analyzed including expressions of surface markers, viability, growth curve, karyotype analysis, tumorigenicity, differentiation potentials, and immune regulation capability. Then, the HUCMSCs with distinct immunomodulatory effects were applied to treat mouse liver fibrosis and their therapeutic effects were observed.

Results

The HUCMSCs derived from multiple donors kept a high consistency in surface marker expressions, viability, growth curve, and tumorigenicity in nude mice but had robust heterogeneities in differentiation potentials and immune regulations. In addition, three HUCMSC lines applied to mice liver fibrosis model had different therapeutic outcomes, in line with individual immune regulation capability.

Conclusion

The HUCMSCs derived from different donors have individual heterogeneity, which potentially lead to distinct therapeutic outcomes in mouse liver fibrosis, indicating we could make use of the donor-variation of MSCs to screen out guaranteed general indicators of MSCs for specific diseases in further stromal cell therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02430-6.

The quality evaluation system establishment of mesenchymal stromal cells for cell-based therapy products

BACKGROUND

Cell-based therapy products are supposed to be the most complex medicine products in the history of human medical care. In this study, we established a safety evaluation system for therapeutic stromal cells based on the existing regulations and current testing techniques to provide general quality requirements for human umbilical cord mesenchymal stromal cell (HUCMSC) therapy product.

METHODS

In this system, we comprehensively evaluate the environmental monitoring program, quality control of critical raw materials and reagents, donor screening criteria, cell safety, quality, and biological effects, not only in line with the basic criteria of biological products, but also following the general requirements of drugs.

RESULTS

The qualified HUCMSCs were tested for various clinical researches in our hospital, and no severe adverse reaction was observed in 225 patients during a 1-year follow-up period.

CONCLUSION

In this study, we establish a systemic quality control and potent assays to guarantee the safety and effectiveness of HUCMSCs based on a minimum set of standards in MSC-based product.

A Reflective Account of a Research Ethics Course for an Interdisciplinary Cohort of Graduate Students

The graduate course in research ethics in the Graduate School for Integrative Sciences and Engineering at the National University of Singapore consists of a semester long mandatory course titled: "Research Ethics and Scientific Integrity." The course provides students with guiding principles for appropriate conduct in the professional and social settings of scientific research and in making morally weighted and ethically sound decisions when confronted with moral dilemmas. It seeks to enhance understanding and appreciation of the moral reasoning underpinning various rules and legislative constraints associated with research subjects and procedures. Further, students are trained to critically analyse cases and issues associated with scientific misconduct preparing them to act in a responsible and effective manner should they encounter such cases. The diverse background and training of the cohort also provide a unique setting and opportunity for student-initiated collaborative interdisciplinary learning. This article offers a reflective account of the course and some preliminary insights into learning outcomes.

Human lung epithelial BEAS-2B cells exhibit characteristics of mesenchymal stem cells

BEAS-2B was originally established as an immortalized but non-tumorigenic epithelial cell line from human bronchial epithelium. Because of general recognition for its bronchial epithelial origin, the BEAS-2B cell line has been widely used as an in vitro cell model in a large variety of studies associated with respiratory diseases including lung carcinogenesis. However, very few studies have discussed non-epithelial features of BEAS-2B cells, especially the features associated with mesenchymal stem cells (MSCs), which represent a group of fibroblast-like cells with limited self-renewal and differentiation potential to various cell lineages. In this study, we compared BEAS-2B with a human umbilical cord-derived MSCs (hMSCs) cell line, hMSC1, which served as a representative of hMSCs in terms of expressing common features of hMSCs. It was observed that both BEAS-2B and hMSC1 shared the same expression profile of surface markers of hMSCs and exhibited similar osteogenic and adipogenic differentiation potential. In addition, like hMSC1, the BEAS-2B cell line exhibited suppressive activities on proliferation of mitogen-activated total T lymphocytes as well as Th1 lymphocytes, and IFNγ-induced expression of IDO1, all thus demonstrating that BEAS-2B cells exhibited an almost identical characteristic profile with hMSCs, even though, there was a clear difference between BEAS-2B and hMSCs in the effects on type 2 macrophage polarization. Most importantly, the hMSCs features of BEAS-2B were unlikely a consequence of epithelial-mesenchymal transition. Therefore, this study provided a set of evidence to provoke reconsideration of epithelial origin of BEAS-2B.

The notch signaling regulates CD105 expression, osteogenic differentiation and immunomodulation of human umbilical cord mesenchymal stem cells

Mesenchymal stem cells (MSCs) are a group of multipotent cells with key properties of multi-lineage differentiation, expressing a set of relatively specific surface markers and unique immunomodulatory functions. IDO1, a catabolic enzyme of tryptophan, represents a critical molecule mediating immunomodulatory functions of MSCs. However, the signaling pathways involved in regulating these key properties still remain elusive. To investigate the involvement of Notch signaling as well as other potential signaling pathway(s) in regulating these critical properties of MSCs, we treated human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) with γ-secreatase inhibitor I (GSI-I), which inhibits both Notch signaling and ubiquitin-proteasome activities. It was shown that the GSI-I treatment resulted in apoptosis, reduced expression of surface markers CD73, CD90 and CD105, reduced osteogenic differentiation, and reduction of the hUC-MSCs-mediated suppression of Th1 lymphocyte proliferation and the IFN-γ-induced IDO1 expression. Through distinguishing the effects of GSI-I between Notch inhibition and proteasome inhibition, it was further observed that, whereas both Notch inhibition and proteasome inhibition were attributable to the reduced CD105 expression and osteogenic differentiation, but not to the induced apoptosis. However, Notch inhibition, but not proteasome inhibition, only contributed to the significant effect of GSI-I on Th1 proliferation probably through reducing IDO1 promoter activity. In conclusion, the Notch signaling may represent a very important cell signaling capable of regulating multiple critical properties, especially the immunomodulatory functions of MSCs.

Establishing a Quality Control System for Stem Cell-Based Medicinal Products in China

Stem cell-based medicinal products (SCMPs) are emerging as novel therapeutic products. The success of its development depends on the existence of an effective quality control system, which is constituted by quality control technologies, standards, reference materials, guidelines, and the associated management system in accordance with regulatory requirements along product lifespan. However, a worldwide, effective quality control system specific for SCMPs is still far from established partially due to the limited understanding of stem cell sciences and lack of quality control technologies for accurately assessing the safety and biological effectiveness of SCMPs before clinical use. Even though, based on the existing regulations and current stem cell sciences and technologies, initial actions toward the goal of establishing such a system have been taken as exemplified by recent development of new "interim guidelines" for governing quality control along development of SCMPs and new development of the associated quality control technologies in China. In this review, we first briefly introduced the major institutions involved in the regulation of cell substrates and therapeutic cell products in China and the existing regulatory documents and technical guidelines used as critical references for developing the new interim guidelines. With focus only on nonhematopoietic stem cells, we then discussed the principal quality attributes of SCMPs as well as our thinking of proper testing approaches to be established with relevant evaluation technologies to ensure all quality requirements of SCMPs along different manufacturing processes and development stages. At the end, some regulatory and technical challenges were also discussed with the conclusion that combined efforts should be taken to promote stem cell regulatory sciences to establish the effective quality control system for SCMPs.

Clinical research skills development program in cell-based regenerative medicine

Cell-based therapy aimed at restoring organ function is one of the most exciting and promising areas of medical research. However, a novel intervention like cell-based therapy requires physician education and training. An increasing number of physicians untrained in regenerative medicine are using cell-based therapy to treat patients for a wide variety of chronic illnesses. The current lack of training for physicians in this area combined with the sharply increasing practice of regenerative medicine is concerning for a number of reasons, namely potential harm to patients and avoidable conflicts between governmental regulatory agencies and physicians. Academic medical fellowship training programs are needed that specifically prepare physicians for treating patients with cell-based therapies for various organ systems and chronic diseases. The National Heart, Lung, and Blood Institute established the Cardiovascular Cell Therapy Network to design and conduct clinical trials that advance the field of cell-based therapy for patients with cardiovascular disease. As part of the network, a two-year Clinical Research Skills Development Program was supported at two centers with the goal of training early career investigators in cell-based clinical and translational research. In this review, we describe the implementation of this training program at our institution with the purpose of promoting the further development of academic fellowship programs in cell-based regenerative medicine.