All Publications

  • Autophagic state prospectively identifies facultative stem cells in the intestinal epithelium EMBO REPORTS Johnson, N. M., Parham, L. R., Na, J., Monaghan, K. E., Kolev, H. M., Klochkova, A., Kim, M. S., Danan, C. H., Cramer, Z., Simon, L. A., Naughton, K. E., Adams-Tzivelekidis, S., Tian, Y., Williams, P. A., Leu, N., Sidoli, S., Whelan, K. A., Li, N., Lengner, C. J., Hamilton, K. E. 2022: e55209


    The intestinal epithelium exhibits a rapid and efficient regenerative response to injury. Emerging evidence supports a model where plasticity of differentiated cells, particularly those in the secretory lineages, contributes to epithelial regeneration upon ablation of injury-sensitive stem cells. However, such facultative stem cell activity is rare within secretory populations. Here, we ask whether specific functional properties predict facultative stem cell activity. We utilize in vivo labeling combined with ex vivo organoid formation assays to evaluate how cell age and autophagic state contribute to facultative stem cell activity within secretory lineages. Strikingly, we find that cell age (time elapsed since cell cycle exit) does not correlate with secretory cell plasticity. Instead, high autophagic vesicle content predicts plasticity and resistance to DNA damaging injury independently of cell lineage. Our findings indicate that autophagic status prior to injury serves as a lineage-agnostic marker for the prospective identification of facultative stem cells.

    View details for DOI 10.15252/embr.202255209

    View details for Web of Science ID 000857851900001

    View details for PubMedID 36120829

  • Limitations to Understanding Intestinal Stem Cell Activity via Cre-Lox-Based Lineage Tracing. Cellular and molecular gastroenterology and hepatology Johnson, N. M., Na, J., Monaghan, K. E., Tang, A. T., Tian, Y., Leu, N. A., Li, N., Kahn, M. L., Lengner, C. J. 2022

    View details for DOI 10.1016/j.jcmgh.2022.08.007

    View details for PubMedID 36031151

  • Human placenta-derived mesenchymal stem cells trigger repair system in TAA-injured rat model via antioxidant effect. Aging Na, J., Song, J., Kim, H. H., Seok, J., Kim, J. Y., Jun, J. H., Kim, G. J. 2020; 13 (1): 61-76


    Oxidative stress induces damages of various cell types or tissues through a repetitive imbalance between the systemic manifestation of reactive oxygen species (ROS) and detoxification of the reactive intermediates. Thioacetamide (TAA) is well known for causing several degenerative diseases by oxidative stress. However, study of the antioxidant mechanisms of stem cells in TAA-injured rat model is insufficient. Therefore, we investigated the effect of placenta-derived mesenchymal stem cells (PD-MSCs) transplantation on liver and ovary of TAA-injured rat models to study the antioxidant effect in degenerative diseases. In TAA-injured rat model, PD-MSCs engrafted into damaged organ including liver and ovary in PD-MSCs transplanted groups (Tx) compared with non-transplanted groups (NTx) (*p<0.05). Transplanted PD-MSCs reduced inflammatory factors and upregulated oxidative stress factors in Tx compared with NTx (*p<0.05). Also, transplanted PD-MSCs enhanced antioxidants factors and organ functional restoration factors in Tx compared with NTx. These data show that PD-MSC transplantation triggers the regeneration of organ (e.g., liver and ovary) damaged by oxidative stress from TAA treatment via activating antioxidant factors. Therefore, these data suggest the therapeutic potential via antioxidant effect and help understand the therapeutic mechanism of PD-MSCs in damaged tissues such as in liver and reproductive system.

    View details for DOI 10.18632/aging.202348

    View details for PubMedID 33406506

    View details for PubMedCentralID PMC7835021

  • Recent trends in stem cell therapy for premature ovarian insufficiency and its therapeutic potential: a review. Journal of ovarian research Na, J., Kim, G. J. 2020; 13 (1): 74


    Stem cell therapy is attracting attention in the field of regenerative medicine and is advancing rapidly. Many recent studies have applied stem cell therapy to treat reproductive system diseases; however, data are not yet available as to whether this therapy shows enhanced therapeutic effects. This paper analyzes recent preclinical studies on stem cell therapy for ovarian dysfunction in several types of animal models. Several clinical trials and pending projects are also discussed. This review will provide a background for developing stem cell therapies to enhance ovarian function.

    View details for DOI 10.1186/s13048-020-00671-2

    View details for PubMedID 32576209

    View details for PubMedCentralID PMC7313218