Current Stem Cell Research & Therapy - Volume 20, Issue 1, 2025

Pulmonary fibrosis (PF) is a fatal disease distinguished by structural destruction and dysfunction, accompanied by continuous accumulation of fibroblasts, which eventually leads to lung failure. Preclinical studies have shown that the administration of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) may be a safe and effective treatment for PF. The purpose of our meta-analysis is to evaluate the efficacy of MSC-EVs therapy and identify therapeutic aspects related to PF.

Our study (up to April 6, 2022) identified English and Chinese, preclinical, controlled, and in vivo studies to examine the application of MSC-EVs in the treatment of PF. The risk of bias (ROB) is assessed using the SYRCLE bias risk tool. The primary outcomes include collagen content, α-smooth muscle actin (α-SMA), hydroxyproline (HYP) content, and transforming growth factor-β1 (TGF-β1).

Thirteen studies were included in this meta-analysis. Ten studies evaluated the collagen content, five studies evaluated the α-SMA, five studies evaluated the HYP content, and six studies evaluated the TGF-β1. Compared to the control group, MSC-EVs therapy was associated with a significant reduction of collagen accumulation, α-SMA, HYP content, and TGF-β1.

The administration of MSC-EVs is beneficial for the treatment of rodent PF models. However, the safety and effectiveness of the application in human PF diseases have yet to be confirmed. The application of MSC-EVs in the treatment of PF needs to be further standardized in terms of source, route of administration, and culture method.

One of the main reasons for cancer resistance to chemotherapy is the presence of cancer stem cells (CSCs) in cancer tissues. It is also believed that CSCs are the unique originators of all tumor cells. On the other hand, the Epithelial-Mesenchymal Transition pathway (EMT) can act as the main agent of metastasis. Therefore, it is possible that targeting CSCs as well as the EMT pathway could help in cancer therapy. Considering that CSCs constitute only a small percentage of the total tumor mass, enrichment before study is necessary. In our previous study, CSCs were enriched in the human colon cancer cell line HT29 by induction of EMT. These CSC-enriched HT29 cells with mesenchymal morphology were named “HT29-shE”. In the present study, these cells were used to investigate the effect of Pioglitazone (Pio) and Cetuximab (Cet) in order to find CSC and EMT targeting agents.

The viability and IC50 rate of cells treated with different concentrations of Pio and Cet were evaluated using the MTT test. EMT and CSC markers and cell morphology were assessed in Pio and Cet treated and untreated HT29-shE cells using flow cytometry, realtime PCR, immunocytochemistry, and microscopic monitoring.

The findings showed that Pio and Cet at concentrations of 250 µM and 40 µg/ml, respectively, decrease cell viability by 50%. Also, they were able to reduce the expression of CSC markers (CD133 and CD44) in the CSC enriched HT29 cell line. Furthermore, Pio and Cet could efficiently reduce the expression of vimentin as a mesenchymal marker and significantly upregulate the expression of E-cadherin as an epidermal marker of EMT and its reverse mesenchymal- to-epithelial transition (MET). In addition, the mesenchymal morphology of HT29-shE changed into epithelial morphology after Cet treatment.

Pio and Cet could inhibit EMT and reduce CSC markers in the EMT induced/CSC enriched cell line. We expect that focus on finding EMT/CSC-targeting agents like these drugs can be helpful for cancer treatment.

Osteoporosis increases bone brittleness and the risk of fracture. Umbilical cord mesenchymal stem cell (UCMSC) treatment is effective, but how to improve the biological activity and clinical efficacy of UCMSCs has not been determined.

A rat model of osteoporosis was induced with dexamethasone sodium phosphate. Highly active umbilical cord mesenchymal stem cells (HA-UCMSCs) and UCMSCs were isolated, cultured, identified, and infused intravenously once at a dose of 2.29 × 10⁶ cells/kg. In the 4th week of treatment, bone mineral density (BMD) was evaluated via cross-micro-CT, tibial structure was observed via HE staining, osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) was examined via alizarin red staining, and carboxy-terminal cross-linked telopeptide (CTX), nuclear factor-κβ ligand (RANKL), procollagen type 1 N-terminal propeptide (PINP) and osteoprotegerin (OPG) levels were investigated via enzyme-linked immunosorbent assays (ELISAs). BMMSCs were treated with 10^-6 mol/L dexamethasone and cocultured with HA-UCMSCs and UCMSCs in transwells. The osteogenic and adipogenic differentiation of BMMSCs was subsequently examined through directional induction culture. The protein expression levels of WNT, β-catenin, RUNX2, IFN-γ and IL-17 in the bone tissue were measured via Western blotting.

The BMD in the healthy group was higher than that in the model group. Both UCMSCs and HA-UCMSCs exhibited a fusiform morphology; swirling growth; high expression of CD73, CD90 and CD105; and low expression of CD34 and CD45 and could differentiate into adipocytes, osteoblasts and chondrocytes, while HA-UCMSCs were smaller in size; had a higher nuclear percentage; and higher differentiation efficiency. Compared with those in the model group, the BMD increased, the bone structure improved, the trabecular area, number, and perimeter increased, the osteogenic differentiation of BMMSCs increased, RANKL expression decreased, and PINP expression increased after UCMSC and HA-UCMSC treatment for 4 weeks. Furthermore, the BMD, trabecular area, number and perimeter, calcareous nodule counts, and OPG/RANKL ratio were higher in the HA-UCMSC treatment group than in the UCMSC treatment group. The osteogenic and adipogenic differentiation of dexamethasone-treated BMMSCs was enhanced after the coculture of UCMSCs and HA-UCMSCs, and the HA-UCMSC group exhibited better effects than the UCMSC coculture group. The protein expression of WNT, β-catenin, and runx2 was upregulated, and IFN-γ and IL-17 expression was downregulated after UCMSC and HA-UCMSC treatment.

HA-UCMSCs have a stronger therapeutic effect on osteoporosis compared with that of UCMSCs. These effects include an improved bone structure, increased BMD, an increased number and perimeter of trabeculae, and enhanced osteogenic differentiation of BMMSCs via activation of the WNT/β-catenin pathway and inhibition of inflammation.

Cancer stem cells (CSC) play an important role in the development of Liver Hepatocellular Carcinoma (LIHC). However, the regulatory mechanisms between acetylation-associated genes (HAGs) and liver cancer stem cells remain unclear.

To identify a set of histone acetylation genes (HAGs) with close associations to liver cancer stem cells (LCSCs), and to construct a prognostic model that facilitates more accurate prognosis assessments for LIHC patients.

LIHC expression data were downloaded from the public databases. Using mRNA expression-based stemness indices (mRNAsi) inferred by One-Class Logistic Regression (OCLR), Differentially Expressed Genes (DEGs) (mRNAsi-High VS. mRNAsi-Low groups) were intersected with DEGs (LIHC VS. normal samples), as well as histone acetylation-associated genes (HAGs), to obtain mRNAsi-HAGs. A risk model was constructed employing the prognostic genes, which were acquired through univariate Cox and Least Shrinkage and Selection Operator (LASSO) regression analyses. Subsequently, independent prognostic factors were identified via univariate and multivariate Cox regression analyses and then a nomogram for prediction of LIHC survival was developed. Additionally, immune infiltration and drug sensitivity analysis were performed to explore the relationships between prognostic genes and immune cells. Finally, the expressions of selected mRNAsi-HAGs were validated in the LIHC tumor sphere by quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) assay and western blot analysis.

Among 13 identified mRNAsi-HAGs, 3 prognostic genes (HDAC1, HDAC11, and HAT1) were selected to construct a risk model (mRNAsi-HAGs risk score = 0.02 * HDAC1 + 0.09 * HAT1 + 0.05 * HDAC11). T-stage, mRNAsi, and mRNAsi-HAGs risk scores were identified as independent prognostic factors to construct the nomogram, which was proved to predict the survival probability of LIHC patients effectively. We subsequently observed strongly positive correlations between mRNAsi-HAGs risk score and tumor-infiltrating T cells, B cells and macrophages/monocytes. Moreover, we found 8 drugs (Mitomycin C, IPA 3, FTI 277, Bleomycin, Tipifarnib, GSK 650394, AICAR and EHT 1864) had significant correlations with mRNAsi-HAGs risk scores. The expression of HDAC1 and HDAC11 was higher in CSC-like cells in the tumor sphere.

This study constructed a mRNAsi and HAGs-related prognostic model, which has implications for potential immunotherapy and drug treatment of LIHC.