Effect of low oxygen tension on transcriptional factor OCT4 and SOX2 expression in New Zealand rabbit bone marrow-derived mesenchymal stem cells

Enhanced immunomodulatory effects of canine adipose tissue-derived mesenchymal stem cells in 3D culture

Introduction

Mesenchymal stem cells (MSCs) have been introduced as a treatment for dogs owing to their immunomodulatory effects. In humans, 3D-cultured MSCs have recently been applied in treating various conditions, including myocardial infarction, liver disease, and kidney disease. This study aimed to evaluate whether the immunomodulatory effects of canine adipose tissue-derived MSCs (cAT-MSCs) are enhanced when cultured in a 3D environment compared to conventional 2D culture.

Methods

cAT-MSC spheroids were generated using ultra-low-adhesion plates. The structural and hypoxic characteristics of these spheroids were assessed via confocal imaging. The expression levels of the stemness markers SOX2 and OCT4 were examined through western blotting. Additionally, the expression of inflammatory factors within the cAT-MSC spheroids was analyzed using RT-PCR and ELISA. The immunomodulatory effects were further evaluated in canine macrophages (DH82) treated with conditioned media (CM) from cAT-MSC spheroids, using RT-PCR and flow cytometry.

Results

3D culture induced hypoxic conditions within the cAT-MSC spheroids and significantly increased the expression of SOX2 and OCT4 (p < 0.05). Moreover, the expression of inflammation-associated factors, including TGF-β1, TSG-6, COX-2, PGE2, and IL-10, was upregulated in the 3D culture (p < 0.05). Treatment of DH82 cells with CM from the cAT-MSC spheroids led to a significant reduction in the expression of pro-inflammatory factors such as TNF-α, IL-1β, and IL-6 (p < 0.01). Additionally, M1 polarization was diminished in DH82 cells exposed to the CM from the cAT-MSC spheroids (p < 0.0001). And M2 polarization was increased in DH82 cells exposed to the CM from the cAT-MSC spheroids (p < 0.0001).

Conclusion

This study confirms that the immunomodulatory effects of MSCs are enhanced in 3D culture. Therefore, 3D cultured MSCs may offer a more effective therapeutic approach than conventional 2D-cultured MSCs for treating canine inflammatory diseases.

Role of apoptotic inhibitors, viability, and differentiation in low oxygen tension of mesenchymal stem cells cultured in a rat model of ovarian failure

Background: Stem cell therapy shows applications potential for malnutrition-induced ovarian failure in rat models. However, it is ineffective because of the lack of viability and differentiation of transplanted stem cells, resulting in low adaptation and survival rates. We aimed to determine whether stem cells cultured under low oxygen (O 2) tension improves the adaptability and viability of stem cells, as well as ovarian failure. Methods: After four days of culturing mesenchymal stem cells (MSCs) in 21% oxygen (normoxia) as the T2 group and 1% oxygen (low O 2 or hypoxia) as the T1 group, 200 million bone marrow-derived MSCs per rat were transplanted into female rats with ovarian failure (15 rats per treatment group). A total of 15 fertile and 15 infertile rats were categorized as the C+ and C- groups, respectively. Results: The slight increase in cells expressing HSP70 (C+, T2, T1, and C- groups were 0.5 a±0.53, 1.7 a±0.82, 6.2 b±1.5, and 9.6 c±1.3, respectively), decrease in cells expressing caspase-3 as an apoptotic inhibitor (C+, T2, T1, and C- groups were 0.2 a±0.42, 0.6 a±0.52, 4.8 b±1.03, and 7.3 c±1.42, respectively), and increase in cells expressing VEGF-1 (C+, T2, T1, and C- groups were 10.8 c±1.55, 8.7 b±0.48, 0.4 a±0.52, and 0.2 a±0.42, respectively) and GDF-9 (C+, T2, T1, and C- groups were 5.8 c±1.47, 4.6 b±0.97, 0.5 a±0.53, and 0.3 a±0.48, respectively) were used as markers for viability and differentiation in ovarian tissue, indicating that MSCs cultured under low O 2 tension were more effective than those cultured under normoxic conditions as a treatment for female rats with ovarian failure. Furthermore, infertile female rats treated with MSCs cultivated under low O 2 tension had an enhanced ovarian tissue shape, as indicated by the increasing Graafian follicle count (C+, T2, T1, and C- groups were 8.9 c±0.74, 4.5 b±0.71, 0.5 a±0.53, and 0.4 a±0.52, respectively). Conclusions: MSCs cultured under low O 2 tension are an effective treatment for malnourished rats with ovarian failure.

Evaluation of the Impact of Pregnancy-Associated Factors on the Quality of Wharton's Jelly-Derived Stem Cells Using SOX2 Gene Expression as a Marker

SOX2 is a recognized pluripotent transcription factor involved in stem cell homeostasis, self-renewal and reprogramming. It belongs to, one of the SRY-related HMG-box (SOX) family of transcription factors, taking part in the regulation of embryonic development and determination of cell fate. Among other functions, SOX2 promotes proliferation, survival, invasion, metastasis, cancer stemness, and drug resistance. SOX2 interacts with other transcription factors in multiple signaling pathways to control growth and survival. The aim of the study was to determine the effect of a parturient’s age, umbilical cord blood pH and length of pregnancy on the quality of stem cells derived from Wharton’s jelly (WJSC) by looking at birth weight and using SOX2 gene expression as a marker. Using qPCR the authors, evaluated the expression of SOX2 in WJSC acquired from the umbilical cords of 30 women right after the delivery. The results showed a significant correlation between the birth weight and the expression of SOX2 in WJSC in relation to maternal age, umbilical cord blood pH, and the length of pregnancy. The authors observed that the younger the woman and the lower the umbilical cord blood pH, the earlier the delivery occurs, the lower the birth weight and the higher SOX2 gene expression in WJSC. In research studies and clinical applications of regenerative medicine utilizing mesenchymal stem cells derived from Wharton’s Jelly of the umbilical cord, assessment of maternal and embryonic factors influencing the quality of cells is critical.

Human amniotic mesenchymal stem cells combined with PPCNg facilitate injured endometrial regeneration

BACKGROUND

Caused by the injury to the endometrial basal layer, intrauterine adhesions (IUA) are characterized by uterine cavity obliteration, leading to impaired fertility. Human amniotic mesenchymal stem cells (hAMSCs) have the potential to promote endometrial regeneration mainly through paracrine ability. PPCNg is a thermoresponsive biomaterial consisted of Poly (polyethylene glycol citrate-co-N-isopropylacrylamide) (PPCN) mixed with gelatin, which has been reported as a scaffold for stem cell transplantation. This study aims to investigate the therapeutic effect of hAMSCs combined with PPCNg transplantation in promoting the regeneration of injured endometrium.

METHODS

hAMSCs were cultured in different concentrates of PPCNg in vitro, and their proliferation, apoptosis and cell cycle were examined by CCK-8 assay and flow cytometry. Immunofluorescence was used to determine the MSCs specific surface markers. The expression of pluripotent genes was analyzed by qRT-PCR. The multiple-lineage differentiation potential was further evaluated by detecting the differentiation-related genes using qRT-PCR and specific staining. The Sprague-Dawley (SD) rat IUA model was established with 95% ethanol. hAMSCs combined with PPCNg were transplanted through intrauterine injection. The retention of DiR-labeled hAMSCs was observed by vivo fluorescence imaging. The endometrium morphology was assessed using hematoxylin and eosin (H&E) and Masson staining. Immunohistochemistry staining was performed to detect biomarkers related to endometrial proliferation, re-epithelialization, angiogenesis and endometrial receptivity. The function of regenerated endometrium was evaluated by pregnancy tests.

RESULTS

hAMSCs maintained normal cell proliferation, apoptosis and cell cycle in PPCNg. Immunofluorescence and qRT-PCR showed that hAMSCs cultured in PPCNg and hAMSCs cultured alone expressed the same surface markers and pluripotent genes. hAMSCs exhibited normal multilineage differentiation potential in PPCNg. Vivo fluorescence imaging results revealed that the fluorescence intensity of hAMSCs combined with PPCNg intrauterine transplantation was stronger than that of direct hAMSCs intrauterine transplantation. Histological assays showed the increase in the thickness of endometrial and the number of endometrial glands, and the remarkably decrease in the fibrosis area in the PPCNg/hAMSCs group. The expressions of Ki-67, CK7, CK19, VEGF, ER and PR were significantly increased in the PPCNg/hAMSCs group. Moreover, the number of implanted embryos and pregnancy rate were significantly higher in the PPCNg/hAMSCs group than in the hAMSCs group.

CONCLUSIONS

PPCNg is suitable for growth, phenotype maintenance and multilineage differentiation of hAMSCs. hAMSCs combined with PPCNg intrauterine transplantation can facilitate the regeneration of injured endometrium by improving utilization rates of hAMSCs, and eventually restore reproductive capacity.