Therapeutic effect of adipose-derived mesenchymal stem cells (ASCs) on radiation-induced skin damage in rats

Emerging role of mesenchymal stem cell-derived exosome microRNA in radiation injury

PURPOSE

Radiation injury (RI) is a common occurrence in malignant tumors patients receiving radiation therapy. While killing tumor cells, normal tissue surrounding the target area is inevitably irradiated at a certain dose, which can cause varying results of radiation injury. Currently, there are limited clinical treatments available for radiation injuries. In recent years, the negative effects of stem cell therapy have been reported more clearly and non-cellular therapies such as exosomes have become a focus of attention for researchers. As a type of vesicle-like substances secreted by mesenchymal stem cells (MSC), MSC derived exosomes (MSC-exo) carry DNA, mRNA, microRNA (miRNAs), specific proteins, lipids, and other active substances involved in intercellular information exchange. miRNAs released by MSC-exo are capable of alleviating and repairing damaged tissues through anti-apoptosis, modulating immune response, regulating inflammatory response and promoting angiogenesis, which indicates that MSC-exo miRNAs have great potential for application in the prevention and treatment of radiation injury. Therefore, it is necessary to explore the underlying therapeutic mechanisms of MSC-exo miRNAs in this process, which may shed new lights on the treatment of radiation injury.

CONCLUSIONS

Increasing evidence confirms that MSC-exo has shown encouraging applications in tissue repair due to the anti-apoptotic, immunoreactive, and pro-angiogenesis effects of the miRNAs it carries as intercellular communication carriers. However, miRNA-based therapeutics are still in their infancy and many practical issues remain to be addressed for clinical applications.

A single-cell transcriptome atlas of Lueyang black-bone chicken skin

As the largest organ of the body, the skin participates in various physiological activities, such as barrier function, sensory function, and temperature regulation, thereby maintaining the balance between the body and the natural environment. To date, compositional and transcriptional profiles in chicken skin cells have not been reported. Here, we report detailed transcriptome analyses of cell populations present in the skin of a black-feather chicken and a white-feather chicken using single-cell RNA sequencing (scRNA-seq). By analyzing cluster-specific gene expression profiles, we identified 12 cell clusters, and their corresponding cell types were also characterized. Subsequently, we characterized the subpopulations of keratinocytes, myocytes, mesenchymal cells, fibroblasts, and melanocytes. It is worth noting that we have identified a subpopulation of keratinocytes involved in pigment granule capture and a subpopulation of melanocytes involved in pigment granule deposition, both of which have a higher cell abundance in black-feather chicken compared to white-feather chicken. Meanwhile, we also compared the cellular heterogeneity features of Lueyang black-bone chicken skin with different feather colors. In addition, we also screened out 12 genes those could be potential markers of melanocytes. Finally, we validated the specific expression of SGK1, WNT5A, CTSC, TYR, and LAPTM5 in black-feather chicken, which may be the key candidate genes determining the feather color differentiation of Lueyang black-bone chicken. In summary, this study first revealed the transcriptome characteristics of chicken skin cells via scRNA-seq technology. These datasets provide valuable information for the study of avian skin characteristics and have important implications for future poultry breeding.

Exploring the mechanisms behind autologous lipotransfer for radiation-induced fibrosis: A systematic review

AIM

Radiation-induced fibrosis is a recognised consequence of radiotherapy, especially after multiple and prolonged dosing regimens. There is no definitive treatment for late-stage radiation-induced fibrosis, although the use of autologous fat transfer has shown promise. However, the exact mechanisms by which this improves radiation-induced fibrosis remain poorly understood. We aim to explore existing literature on the effects of autologous fat transfer on both in-vitro and in-vivo radiation-induced fibrosis models, and to collate potential mechanisms of action.

METHOD

PubMed, Cochrane reviews and Scopus electronic databases from inception to May 2023 were searched. Our search strategy combined both free-text terms with Boolean operators, derived from synonyms of adipose tissue and radiation-induced fibrosis.

RESULTS

The search strategy produced 2909 articles. Of these, 90 underwent full-text review for eligibility, yielding 31 for final analysis. Nine conducted in-vitro experiments utilising a co-culture model, whilst 25 conducted in-vivo experiments. Interventions under autologous fat transfer included adipose-derived stem cells, stromal vascular function, whole fat and microfat. Notable findings include downregulation of fibroblast proliferation, collagen deposition, epithelial cell apoptosis, and proinflammatory processes. Autologous fat transfer suppressed hypoxia and pro-inflammatory interferon-γ signalling pathways, and tissue treated with adipose-derived stem cells stained strongly for anti-inflammatory M2 macrophages. Although largely proangiogenic initially, studies show varying effects on vascularisation. There is early evidence that adipose-derived stem cell subgroups may have different functional properties.

CONCLUSION

Autologous fat transfer functions through pro-angiogenic, anti-fibrotic, immunomodulatory, and extracellular matrix remodelling properties. By characterising these mechanisms, relevant drug targets can be identified and used to further improve clinical outcomes in radiation-induced fibrosis. Further research should focus on adipose-derived stem cell sub-populations and augmentation techniques such as cell-assisted lipotransfer.

The Therapeutic Application of Stem Cells and Their Derived Exosomes in the Treatment of Radiation-Induced Skin Injury

Radiation-induced skin injury (RISI) is a serious concern for nuclear accidents and cancer radiotherapy, which seriously affects the quality of life of patients. This injury differs from traditional wounds due to impaired healing and the propensity to recurrence and is divided into acute and chronic phases on the basis of the injury time. Unfortunately, there are few effective therapies for preventing or mitigating this injury. Over the last few decades, various studies have focused on the effects of stem cell-based therapies to address the tissue repair and regeneration of irradiated skin. These stem cells modulate inflammation and instigate tissue repair by differentiating into specific kinds of cells or releasing paracrine factors. Stem cell-based therapies, including bone marrow-derived stem cells (BMSCs), adipose-derived stem cells (ADSCs) and stromal vascular fraction (SVF), have been reported to facilitate wound healing after radiation exposure. Moreover, stem cell-derived exosomes have recently been suggested as an effective and cell-free approach to support skin regeneration, circumventing the concerns respecting direct application of stem cells. Based on the literature on stem cell-based therapies for radiation-induced skin injury, we summarize the characteristics of different stem cells and describe their latest animal and clinical applications, as well as potential mechanisms. The promise of stem-cell based therapies against radiation-induced skin injury contribute to our response to nuclear events and smooth progress of cancer radiotherapy.

Platelet Rich Plasma Hybridized Adipose Transplant (PHAT) for the Treatment of Hair Loss: A Case Series

BACKGROUND

Platelet-rich plasma (PRP) has long been used for the restoration of hair in conjunction with microneedling or on its own. Fat grafting to the scalp has also been utilized in the past to improve the quality of hair and the possibility of successful hair transplant. The novel therapy reported in this case series combines the natural progression of these two techniques and utilizes synergistic effects to improve the quality of hair, either in preparation for micrografting or without hair transplant.

OBJECTIVES

To demonstrate the principles behind the novel approach to restoration of hair and the rationale for its use.

METHODS

A review of the evidence for PRP and fat transfer for non-scarring alopecia serves as the foundation for the combination treatment reported herein. Through presentation of three cases in this series, we provide examples of the utility of this approach for non-scarring alopecia. This report includes a female who suffered non-scarring alopecia following COVID-19 hospitalization and intensive care stay where she lost a large percentage of her hair, in addition to two male patients suffering from androgenic alopecia.

RESULTS

Platelet-rich plasma-hybridized adipose transplant hair was shown in these three cases to improve both the quality and density of hair. It improved the density of hair in all patients and was characterized first by a short period of transient hair loss followed by new hair growth which develops starting at 4 weeks and was readily apparent at 12-week follow-up. Results were maintained at 6-month and 1-year follow-up.

CONCLUSIONS

PHAT hair offers a combination of beneficial effects-namely the unique healing properties and growth signaling provided by PRP, along with adipocyte angiogenic and growth signaling, which both work to improve scalp quality. The combination of these effects is better than previously characterized PRP injections alone in the hands of these individual practices. This may be due to synergistic interactions at a cellular level, but additional clinical studies are needed to better understand this novel treatment and the observed effects.

LEVEL OF EVIDENCE IV

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