Stemazole promotes survival and preserves stemness in human embryonic stem cells

Boldine promotes stemness of human urine-derived stem cells by activating the Wnt/β-catenin signaling pathway

Human urine-derived stem cells (hUSCs) process self-renewal and multilineage differentiation ability. Due to their non-invasive and easily available clinical source, hUSCs represent a promising alternative source of mesenchymal stem cells (MSCs) for application potential in cytotherapy. However, technical limitations, such as stemness property maintenance, have hindered hUSCs' clinical application. Certain some small molecules have been recognized with advantage in maintaining the stemness of stem cells. In this study, we identified stemness-regulated key targets of hUSCs based on the StemCellNet database, CMAP database and literature mining. Furthermore, we identified a small molecule compound, boldine, which may have the potential to promote the stemness of hUSCs. It promotes cell proliferation, multilineage differentiation and maintains stemness of hUSCs by cell viability assay, single-cell clone formation, osteogenic differentiation and stemness marker expression (OCT-4 and C-MYC). We identified that boldine may be a potential GSK-3β inhibitor by molecular docking and confirmed that it can upregulate the level of β-catenin and promote translocation of β-catenin into nucleus of hUSCs using Western blotting and immunofluorescence analysis. Our study indicates boldine activates the Wnt/β-catenin signaling pathway in hUSCs and provides an effective strategy for MSCs research and application of small molecules in maintaining the stemness of hUSCs.

Stemazole Promotes Oligodendrocyte Precursor Cell Survival In Vitro and Remyelination In Vivo

Maintaining the normal function of oligodendrocyte precursor cells (OPCs) and protecting OPCs from damage is the basis of myelin regeneration in multiple sclerosis (MS). In this paper, we investigated the effect of stemazole, a novel small molecule, on the promotion of oligodendrocyte precursor cell survival and remyelination. The results show that stemazole enhanced the survival rate and the number of clone formation in a dose-dependent manner and decreased the percentage of cell apoptosis. In particular, the number of cell clones was increased up to 6-fold (p < 0.001) in the stemazole group compared with the control group. In vivo, we assessed the effect of stemazole on recovering the motor dysfunction and demyelination induced by cuprizone (CPZ). The results show that stemazole promoted the recovery of motor dysfunction and the repair of myelin sheaths. Compared with the CPZ group, the stemazole group showed a 30.46% increase in the myelin area (p < 0.001), a 37.08% increase in MBP expression (p < 0.01), and a 1.66-fold increase in Olig2 expression (p < 0.001). Histologically, stemazole had a better effect than the positive control drugs. In conclusion, stemazole promoted OPC survival in vitro and remyelination in vivo, suggesting that this compound may be used as a therapeutic agent against demyelinating disease.

A Quantitative Proteomic Approach Explores the Possible Mechanisms by Which the Small Molecule Stemazole Promotes the Survival of Human Neural Stem Cells

Neurodegenerative disorders have become a serious healthcare problem worldwide and there is no efficacious cure. However, regulating the fate of stem cells is an effective way to treat these neurological diseases. In previous work, stemazole was reported to maintain the survival of human neural stem cells in the absence of growth factors and to have therapeutic effects on neurodegenerative diseases. However, although it is a promising small molecule, the molecular mechanisms against apoptosis are ambiguous. In this study, tandem mass tag (TMT)-based proteomics were performed to obtain whole protein expression profiles of human neural stem cells in different groups under extreme conditions. Bioinformatics analysis based on protein–protein interaction (PPI) network construction, gene ontology (GO) and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analysis were adopted to explore crucial proteins and possible pharmacological mechanisms. A total of 77 differentially expressed proteins were identified, comprising 38 upregulated proteins and 39 downregulated proteins. Combined with a diseases database of Alzheimer’s disease (AD), caspase-2 (CASP2), PKA C-alpha (PRKACA), fibronectin (FN1), large neutral amino acid transporter small subunit 1 (SLC7A5), which are involved in cell proliferation and apoptosis, this was further validated by enzyme activity assay and molecular docking, and regarded as putative targets regulated by stemazole. The present results give an insight into this small molecule and a better understanding for further elucidating the underlying mechanisms in the treatment of stem cells and neurodegenerative diseases.

Microglia in Alzheimer's Disease: The Role of Stem Cell-Microglia Interaction in Brain Homeostasis

Microglia as resident cells of the brain can regulate neural development and maintenance of neuronal networks. Any types of pathologic events or changes in brain homeostasis are involved in the activation of microglia. This activation depends on the context, type of the stressor, or pathology. Due to the release of a plethora of substances such as chemokines, cytokines, and growth factors, microglia able to influence the pathologic outcome. In Alzheimer's disease (AD) condition, the deposition of amyloid-β (Aβ) result in provokes the phenotypic activation of microglia and their elaboration of pro-inflammatory molecules. New investigations reveal that cellular therapy with stem cells might have therapeutic effects in preventing the pathogenesis of AD. Although many strategies have focused on the use of stem cells to regenerate damaged neurons, new researches have demonstrated the immune-regulatory feature of stem cells which can modulate the activity state of microglia as well as mediates neuroinflammation. Hence, understanding the molecular mechanisms involved in the brain homeostasis by the protective features of mesenchymal stem cells (MSCs) could lead to remedial treatment for AD.

A quantitative proteomics analysis for small molecule Stemazole's effect on human neural stem cells

BACKGROUND

Stemazole is a novel small molecule that has been suggested to have the ability to protect multiple stem cells. The proliferation-promoting activity and promising neuroprotective effects of stemazole make it a prospective drug for neurodegenerative disease treatment.

METHODS

Since previous studies have shown that it protective effect in extreme conditions, to understand more aspects of stemazole, in this study, a systematic tandem mass tags (TMT)-labelled proteomics approach was used to address the whole proteome expression profile with or without stemazole in normal conditions instead of extreme conditions. Bioinformatics analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and protein-protein interaction (PPI) network analyses, were employed.

RESULTS

The effect of stemazole on the expression profiles of neural stem cells was obtained. A total of 408 proteins with changes at the abundance level of two groups were identified: 178 proteins increase in abundance and 240 proteins decrease in abundance, respectively. Low abundance of some mitochondrial respiratory chain enzyme, overproduction of reactive oxygen species (ROS) and reduction of mitochondrial membrane potential may indicate stemazole has cytotoxicity.

CONCLUSIONS

It is the first proteomics research about stemazole, and the possible cytotoxicity of stemazole has been reported for the first time. The information about proteins that were affected by stemazole and more characteristics of stemazole will help obtain a complete picture of this small molecule drug. These findings provide a scientific basis for further stemazole treatment research.

Uncovering the Pharmacological Mechanism of Stemazole in the Treatment of Neurodegenerative Diseases Based on a Network Pharmacology Approach

Stemazole exerts potent pharmacological effects against neurodegenerative diseases and protective effects in stem cells. However, on the basis of the current understanding, the molecular mechanisms underlying the effects of stemazole in the treatment of Alzheimer's disease and Parkinson's disease have not been fully elucidated. In this study, a network pharmacology-based strategy integrating target prediction, network construction, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, and molecular docking was adopted to predict the targets of stemazole relevant to the treatment of neurodegenerative diseases and to further explore the involved pharmacological mechanisms. The majority of the predicted targets were highly involved in the mitogen-activated protein kinase (MAPK) signaling pathway. RAC-alpha serine/threonine-protein kinase (AKT1), caspase-3 (CASP3), caspase-8 (CASP8), mitogen-activated protein kinase 8 (MAPK8), and mitogen-activated protein kinase 14 (MAPK14) are the core targets regulated by stemazole and play a central role in its anti-apoptosis effects. This work provides a scientific basis for further elucidating the mechanism underlying the effects of stemazole in the treatment of neurodegenerative diseases.

Pharmacokinetics and absolute oral bioavailability of stemazole by UPLC-MS/MS and its bio-distribution through tritium labeling

The small molecule, stemazole, has significant therapeutic effects on neurodegenerative diseases, such as Alzheimer's disease (AD), due to its neuroprotective effects and remarkable survival-promoting activity in stem cells. However, pharmacokinetic properties of stemazole were unclear. In this study, a rapid and effective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to detect stemazole. The detector was operated in the positive-ion mode with an electrospray ionization (ESI) interface in multiple reaction monitoring (MRM) mode. Chromatographic separation was performed on an Acquity UPLC^® BEH C₁₈ column with gradient elution. Stemazole was extracted from plasma following a one-step protein precipitation method. The method was fully validated for its selectivity, specificity, and sensitivity. The calibration curve range of 5-1125 ng/mL showed good linearity for stemazole. Intra-day and inter-day precision rates were less than 10%, and accuracy ranged from 95.87% to 105.23%. The pharmacokinetic profiles were illustrated through the newly developed method for the first time. The absolute oral bioavailability of stemazole is 32.10%. Therefore, it is feasible as an oral medication, which greatly facilitates its broad application. The biological distribution of tritium-labeled stemazole in mice was studied, and the results showed that stemazole was absorbed rapidly and distributed widely, mainly in the liver and kidneys. A specific amount was also detected in the brain, which provides a prerequisite for the use of stemazole to treat neurodegenerative diseases. This work represents first description of the pharmacokinetics, bioavailability, and tissue distribution of stemazole and will lay the foundation for further investigation and drug development.