Dynamic expression characteristics of Notch signal in bone marrow-derived mesenchymal stem cells during the process of differentiation into hepatocytes. Tissue Cell. 2013;45:95-100. [PMID: 23116754 DOI: 10.1016/j.tice.2012.09.008]

SiNiSan alleviates liver injury by promoting hepatic stem cell differentiation via Wnt/β-catenin signaling pathway

BACKGROUND

SiNiSan, a Traditional Chinese Medicine containing Radix Bupleuri, Radix Paeoniae Alba, Fructus Aurantii Immaturus, and Radix Glycyrrhizae, has been shown to be clinically effective in treating liver damage, its underlying molecular mechanisms however remains unclear.

PURPOSE

The aim of the current study was to understand the molecular mechanisms of SiNiSan in the treatment of liver damage utilizing mice and cell culture models.

METHODS

Here, mice were gavaged with 0.2% CCl4 to obtain acute liver injury model and with alcohol to obtain chronic liver injury model. H&E staining was performed to detect liver histomorphology. HPLC-MS was performed to analyze the composition of SiNiSan decoction and SiNiSan-medicated serum (SMS). In addition, western blots were done to analyze the representative protein expression in Wnt/β-catenin signaling. Immunofluorescence staining was done to analyze the protein levels in WB-F344 cells. Finally, in an attempt to measure the influence of SiNiSan on liver regeneration in rats, we constructed a rats partial hepatectomy models.

RESULTS

We demonstrated that SiNiSan treatment mitigated liver damage in mice, as evidenced by the decrease in serum AST and ALT levels, as well as improved liver tissue morphology. HPLC-MS results showed that SMS contained a variety of components from the SiNiSan decoction. Next, our results showed that SMS reduced the expression of α-fetoprotein (AFP) and enhanced the expression of albumin (ALB) and cytokeratin 19 (CK19) in WB-F344 cells. Further, SMS treatment induced the accumulation of β-catenin. After 14 days of SMS treatment, β-catenin protein underwent nuclear translocation and bound to the LEF1 receptor in the nucleus, which regulated c-Myc and Cyclin D1 factors to activate Wnt/β-catenin signaling and promoted differentiation of WB-F344 cells. In addition, we demonstrated that SiNiSan increased liver regeneration in rat hepatectomy.

CONCLUSION

Collectively, the current study revealed that SiNiSan alleviated the acute liver injury induced by CCl4 as well as the chronic liver damage triggered by alcohol and sucrose in vitro. Concurrently, SMS treatment induced hepatic stem cell differentiation by activating Wnt/β-catenin signaling in vivo. Further study showed that SiNiSan promoted the regeneration of rats liver. The current study provides a theoretical basis for the clinical treatment of liver-related diseases with SiNiSan.

Doxorubicin combined with Notch1-targeting siRNA for the treatment of gastric cancer

Notch1, a transmembrane receptor that has a notable role in gastric cancer (GC) as an oncogene, has been reported to be involved in doxorubicin resistance. Thus, Notch1 is a potential therapeutic target for GC. In the present study, the protein levels of Notch1 intracellular domain (NICD; a marker of Notch1 activation) in human GC cell lines and tumor tissues was measured by western blotting. Next, the effects of Notch1 depletion in SGC7901 cells were evaluated. Finally, the efficacy of Notch1 small interfering RNA (siRNA) combined with doxorubicin therapy for GC was examined in vitro and in vivo. The results revealed that NICD levels were high in GC cells, and that the inhibition of NICD by transfection with Notch1 siRNA induced apoptosis and inhibited proliferation. Ectopic downregulation of Notch1 expression enhanced the sensitivity of GC tumors to doxorubicin, which suppressed the development of GC. These data demonstrated that Notch1 was a significant regulator of cell proliferation and apoptosis in GC. Thus, the combination of doxorubicin with Notch1 siRNA is a potential strategy for the treatment of GC.

Role of Magnesium Transporter Subtype 1 (MagT1) in the Osteogenic Differentiation of Rat Bone Marrow Stem Cells

In the present study, we investigated the role of magnesium transporter subtype 1 (MagT1), a selective Mg transporter protein, in the osteogenic differentiation of rat bone marrow stem cells (rBMSCs). Osteogenic differentiation was monitored by the expressions of alkaline phosphatase (ALP), osteocalcin (OCN), collagen-1 (COL-1) and runt-related transcription factor 2 (RUNX2), and extracellular matrix mineralization of rBMSCs. The expression of MagT1 increased with osteogenic differentiation of rBMSCs, suggesting the importance of intracellular Mg homeostasis to cell differentiation. Alteration of intracellular Mg homeostasis by culture condition with low extracellular Mg significantly reduced the osteogenic differentiation markers ALP, OCN, COL-1, and RUNX2 gene expressions. MagT1 knockdown during the differentiation period also reduced osteogenic differentiation and the extent of matrix mineralization of rBMSCs. In conclusion, our results indicate that Mg and MagT1 play an important role in osteogenic differentiation of rBMSCs and may be involved in the bone regeneration.

Superior performance of co-cultured mesenchymal stem cells and hepatocytes in poly(lactic acid-glycolic acid) scaffolds for the treatment of acute liver failure

Recently, cell-based therapies have attracted attention as promising treatments for acute liver failure (ALF). Bone marrow-derived mesenchymal stem cells (MSCs) are potential candidates for co-culture with hepatocytes in poly(lactic acid-glycolic acid) (PLGA) scaffolds to support hepatocellular function. However, the mechanism of culturing protocol using PLGA scaffolds for MSC differentiation into hepatocyte-like cells as well as the therapeutic effect of cell seeded PLGA scaffolds on ALF remain unsatisfactory in clinical application. Here, MSCs and hepatocytes were co-cultured at ratios of 1:2.5 (MSCs: Hep), 1:5 and 1:10, respectively. The proliferation abilities of these co-cultured cells were detected by CCK8, MTT, EdU and by scanning electron microscopy (SEM), and the ability of MSCs to differentiate into hepatocytes was detected by PCR, western blot and immunofluorescence staining. Therapeutic trials of cell seeded PLGA scaffolds were conducted through mouse abdominal cavity transplantation. Results showed that the 1:5 group showed significantly higher cellular proliferation than the 1:2.5 and 1:10 groups, supernatant albumin and urea nitrogen levels were also significantly higher in the 1:5 group than in other two groups. Similarly, the 1:5 group demonstrated better DNA transcription and liver-specific protein (albumin, CK18 and P450) production. Meanwhile, the GalN-stimulated levels of ALT, AST and TBil in mouse serum were down-regulated significantly more by (MSC  +  Hep)-PLGA scaffold treatment than MSC-PLGA or Hep-PLGA scaffold treatments. Furthermore, the (MSC  +  Hep)-PLGA scaffold-treated ALF mice showed a lower immunogenic response level than the other two groups. These data suggested that the ratio of 1:5 (MSC:Hep) co-cultures was the optimal ratio for MSCs to support hepatocellular metabolism and function in PLGA scaffolds in vitro, the (MSC  +  Hep)-PLGA scaffold treatment could perform better restoration for damaged liver function and could give ALF mice a greater survival rate than the monocell seeded PLGA scaffold treatment.

Changes in biochemical markers of liver fibrosis in patients with decompensated liver cirrhosis after autologous bone marrow stem cell infusion

AIM: To evaluate the effect of autologous bone marrow stem cell infusion on biochemical markers of liver fibrosis in patients with decompensated liver cirrhosis.

METHODS: Fifty patients with decompensated liver cirrhosis were included in the study. The bone marrow harvested from the ilium of patients was isolated and purified, and the final bone marrow stem cells were administered via the hepatic artery. The levels of biochemical markers of liver fibrosis were examined before transplantation, 4 and 8 wk after transplantation. Clinical manifestations and complications of transplantation were recorded during the follow-up period.

RESULTS: The level of serum albumin and the extent of ascites were improved significantly at 4 and 8 wk after transplantation than before transplantation (P < 0.05). The levels of serum alanine aminotransferase, total bilirubin, and prothrombin activity were improved after transplantation, however, the changes were not statistically significant (P > 0.05). Biochemical markers of liver fibrosis such as procollagen type Ⅲ, type Ⅳ collagen, laminin, and hyaluronic acid enzyme were decreased after treatment, of which procollagen type Ⅲ and hyaluronic acid enzyme were improved significantly (P < 0.05).

CONCLUSION: Biochemical markers of liver fibrosis are improved in patients with decompensated liver cirrhosis after autologous bone marrow stem cell infusion.

Comparison of the transcriptomes of mouse skin derived precursors (SKPs) and SKP-derived fibroblasts (SFBs) by RNA-Seq

Skin-derived precursors (SKPs) from dermis possess the capacities of self-renewal and multipotency. In vitro and in vivo studies demonstrated that they can differentiate into fibroblasts. However, little is known about the molecular mechanism of the differentiation of SKPs into fibroblasts. Here we compare the transcriptomes of mouse SKPs and SKP-derived fibroblasts (SFBs) by RNA-Seq analysis, trying to find differences in gene expression between the two kinds of cells and then elucidate the candidate genes that may play important roles in the differentiation of SKPs into fibroblasts. A total of 1971 differentially expressed genes (DEGs) were identified by RNA-Seq, which provided abundant data for further analysis. Gene Ontology enrichment analysis revealed that genes related to cell differentiation, cell proliferation, protein binding, transporter activity and membrane were significantly enriched. The most significantly up-regulated genes Wnt4, Wisp2 and Tsp-1 and down-regulated genes Slitrk1, Klk6, Agtr2, Ivl, Msx1, IL15, Atp6v0d2, Kcne1l and Thbs4 may play important roles in the differentiation of SKPs into fibroblasts. KEGG analysis showed that DEGs were significantly enriched in the TGF-β signaling pathway, Wnt signaling pathway and Notch signaling pathway, which have been previously proven to regulate the differentiation and self-renewal of various stem cells. These identified DEGs and pathways could facilitate further investigations of the detailed molecular mechanisms, making it possible to take advantage of the potential therapeutic applications of SKPs in skin regeneration in the future.

In vitro proliferation and differentiation potential of bone marrow-derived mesenchymal stem cells from ovariectomized rats

Bone marrow-derived mesenchymal stem cells (BMMSCs) from the patients suffering from age-related osteoporosis were found to have numerous degeneration, such as decreased growth rate, impaired capacity of differentiating into local tissue, and repressed telomerase activity. However, it is not clear whether post-menopausal osteoporotic bone is either subject to such decline in cellular function. In the present study, bone marrow cells were harvested from ovariectomized (OVX) and Sham rats and cultured in vitro at 3 months post-surgery. MTT assay indicated that the proliferation potential of (OVX)BMMSCs was always higher than that of (Sham)BMMSCs, no matter cultured in basic, osteoblastic or adipogenic medium. Alkaline phosphatase activity assay, Alizarin red S staining, Oil red O staining and real-time RT-PCR analysis further demonstrated that bilateral ovariectomization positively influenced the osteoblastic and adipogenic differentiation potential of BMMSCs, this action may be partly mediated through up-regulation of osteoblastic special markers core binding factor a1, collagen type I and low-density lipoprotein receptor-related protein 5, as well as adipogenic special markers peroxisome proliferators activated receptor gamma, CCAAT/enhancer binding protein alpha and adipocyte lipid-binding protein 2. These results may hold great promise for using post-menopausal osteoporotic bone as an attractive autologous marrow source for tissue engineering and cell-based therapies.