Stem Cell Reviews and Reports最新文献

Background: Mesenchymal stromal/stem cells (MSCs) have been suggested for salivary gland (SG) restoration following radio-induced salivary gland damage. This study aimed to determine the safety and effectiveness of MSC therapy on radio-induced SG damage and hypofunction in preclinical in vivo studies.

Methods: PubMed and EMBASE were systematically searched for preclinical in vivo interventional studies evaluating efficacy and safety of MSC treatment following radio-induced salivary gland damage published before 10th of January 2022. The primary endpoint was salivary flow rate (SFR) evaluated in a meta-analysis. The study protocol was published and registered on PROSPERO ( www.crd.ac.uk/prospero ), registration number CRD42021227336.

Results: A total of 16 preclinical in vivo studies were included for qualitative analysis (858 experimental animals) and 13 in the meta-analysis (404 experimental animals). MSCs originated from bone marrow (four studies), adipose tissue (10 studies) and salivary gland tissue (two studies) and were administered intravenously (three studies), intra-glandularly (11 studies) or subcutaneously (one study). No serious adverse events were reported. The overall effect on SFR was significantly increased with a standardized mean difference (SMD) of 6.99 (95% CI: 2.55-11.42). Studies reported improvements in acinar tissue, vascular areas and paracrine factors.

Conclusion: In conclusion, this systematic review and meta-analysis showed a significant effect of MSC therapy for restoring SG functioning and regenerating SG tissue following radiotherapy in preclinical in vivo studies without serious adverse events. MSC therapy holds significant therapeutic potential in the treatment of radio-induced xerostomia, but comprehensive, randomized, clinical trials in humans are required to ascertain their efficacy in a clinical setting.

Background: Dental pulp regeneration therapy is a challenge to achieve early vascularization during treatment. Studying the regulatory mechanisms of vascular formation during human dental pulp development may provide insights for related therapies. In this study, we utilized single-cell sequencing analysis to compare the gene expression of dental pulp stem cells (DPSCs) and vascular endothelial cells (ECs) from developing and mature dental pulps.

Method: Immunohistochemistry, Western blot, and real-time polymerase chain reaction (RT-PCR) were used to detect fibronectin 1 (FN1) expression and molecules, such as PI3K/AKT. Cell proliferation assay, scratch assay, tube formation assay and were used to investigate the effects of DPSCs on the vasculogenetic capability of ECs. Additionally, animal experiments involving mice were conducted.

Result: The results revealed that DPSCs exist around dental pulp vasculature. FN1 expression was significantly higher in DPSCs from young permanent pulps than mature pulps, promoting HUVEC proliferation, migration, and tube formation via ITGA5 and the downstream PI3K/AKT signaling pathway.

Conclusion: Our data indicate that intercellular communication between DPSCs and ECs mediated by FN1-ITGA5 signaling is crucial for vascularizationduring dental pulp development, laying an experimental foundation for future clinical studies.

Malfunction in spermatogenesis due to genetic diseases, trauma, congenital disorders or gonadotoxic treatments results in infertility in approximately 7% of males. The behavior of spermatogonial stem cells (SSCs) within three-dimensional, multifactorial, and dynamic microenvironment implicates a niche that serves as a repository for fertility, since can serve as a source of mature and functional male germ cells. Current protocols enable reprogramming of mature somatic cells into induced pluripotent stem cells (iPSCs) and their limited differentiation to SSCs within the range of 0–5%. However, the resulting human iPSC-derived haploid spermatogenic germ cell yield in terms of number and functionality is currently insufficient for transfer to infertility clinic as a therapeutic tool. In this article, we reviewed the evolution of experimental culture platforms and introduced a novel iPSCs-based approach for in vitro spermatogenesis based on a niche perspective bearing cellular, chemical, and physical factors that provide the complex arrangement of testicular seminiferous tubules embedded within a vascularized stroma. We believe that bioengineered organoids supported by smart bio-printed tubules and microfluidic organ-on-a-chip systems offer efficient, precise, personalized platforms for autologous pluripotent stem cell sources to undergo the spermatogenetic cycle, presenting a promising tool for infertile male patients with complete testicular aplasia.

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Various groups including animal protection organizations, medical organizations, research centers, and even federal agencies such as the U.S. Food and Drug Administration, are working to minimize animal use in scientific experiments. This movement primarily stems from animal welfare and ethical concerns. However, recent advances in technology and new studies in medicine have contributed to an increase in animal experiments throughout the years. With the rapid increase in animal testing, concerns arise including ethical issues, high cost, complex procedures, and potential inaccuracies.

Alternative solutions have recently been investigated to address the problems of animal testing. Some of these technologies are related to stem cell technologies, such as organ-on-a-chip, organoids, and induced pluripotent stem cell models. The aim of the review is to focus on stem cell related methodologies, such as organoids, that can serve as an alternative to animal testing and discuss its advantages and limitations, alongside regulatory considerations.

Although stem cell related methodologies has shortcomings, it has potential to replace animal testing. Achieving this requires further research on stem cells, with potential societal and technological benefits.

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Endometrial stem/progenitor cells are a type of stem cells with the ability to self-renew and differentiate into multiple cell types. They exist in the endometrium and form niches with their neighbor cells and extracellular matrix. The interaction between endometrial stem/progenitor cells and niches plays an important role in maintaining, repairing, and regenerating the endometrial structure and function. This review will discuss the characteristics and functions of endometrial stem/progenitor cells and their niches, the mechanisms of their interaction, and their roles in endometrial regeneration and diseases. Finally, the prospects for their applications will also be explored.

Purinergic signaling is an ancient primordial signaling system regulating tissue development and specification of various types of stem cells. Thus, functional purinergic receptors are present in several types of cells in the body, including multiple populations of stem cells. However, one stem cell type that has not been evaluated for expression of purinergic receptors is very small embryonic stem cells (VSELs) isolated from postnatal tissues. Herein, we report that human umbilical cord blood (UCB) and murine bone marrow (BM) purified VSELs express mRNA for P1 and P2 purinergic receptors and CD39 and CD73 ectonucleotidases converting extracellular ATP (eATP) into its signaling metabolite extracellular adenosine (eAdo), that antagonizes eATP effects. More importantly, we demonstrate that human and murine VSELs respond by chemotaxis to eATP, and eAdo inhibits this migration. These responses to eATP are mediated by activation of Nlrp3 inflammasome, and exposure of VSELs to its specific inhibitor MCC950 abolished the chemotactic response to ATP. We conclude that purinergic signaling plays an essential, underappreciated role in the biology of these cells and their potential role in response to tissue/organ injuries.

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