The combination of Decitabine and EPZ-6438 effectively facilitate adipogenic differentiation of induced pluripotent stem cell-derived mesenchymal stem cells

5-Azacytidine inhibits endoplasmic reticulum stress and apoptosis of nucleus pulposus cells by preserving PPARγ via promoter demethylation

Low back pain (LBP) is a common symptom of intervertebral disc degeneration (IDD). However, the pathogenesis of IDD is not well understood. Several studies have shown that patients with IDD experience aberrant changes in DNA methylation. 5-Azacytidine (5Aza) is a nucleoside-based DNA methyltransferase inhibitor that inhibits DNA methylation. Therefore, this study investigated whether 5Aza can improve the apoptosis of nucleus pulposus (NP) cells and ER stress (ERS) induced by il-1β by inhibiting PPARγ methylation and its potential pathogenesis. NP cell viability was detected using Cell Counting Kit-8 (CCK-8). Methylation-specific PCR (MSP) was used to evaluate the DNA methylation level. TUNEL was used to evaluate the apoptosis of NP cells. Western blot determined the expression levels of DNMT1, DNMT3a, PPARγ proteins, and ERS-related indexes (C/EBP homology protein (CHOP), GRP78, ATF-6) and apoptosis-related indexes (Bcl-2, Bax, Caspase-3) protein expression levels. 5Aza can inhibit the expression of DNMT1 and DNMT3a and promote PPARγ by modifying the methylation of PPARγ promoter. Western blot (Bcl-2, Bax, Caspase-3, CHOP, GRP78, ATF-6), TUNEL, and CHOP immunofluorescence results showed that 5Aza attenuated IL-1β-induced apoptosis and ERS of NP cells. When pretreated with PPARγ inhibitor (T0070907), the protective effect of 5Aza on IL-1β-induced apoptosis and ERS in NP cells is weakened, suggesting that 5Aza inhibits IL-1β-induced NP cell apoptosis and ERS by promoting the expression of PPARγ. 5Aza preserves PPARγ by inhibiting the expression of DNMT1/DNMT3a, which can significantly reduce IL-1β damage in NP cells. Our findings suggest that preserving PPARγ through DNA demethylation may be an attractive strategy for preventing or treating IDD.

Umbilical Cord Blood-Derived Cells Can Reconstruct Hematopoiesis in an Aplastic Anemia Animal Model

Objectives

To explore the efficacy and the mechanism of the umbilical cord-derived cells combined with cyclosporine A (CsA) in treating aplastic anemia (AA) in mice.

Methods

Immune-mediated AA model mice were treated with CsA + UC mesenchymal stem cells (UC-MSC), CsA + umbilical cord blood regulatory T cells (UCB-Treg), UC-MSC, UCB-Treg, CsA alone, or blank control, respectively (n = 9 mice/group). CsA and the cell infusion was administered on d0. Routine peripheral blood testing was performed once weekly; bone marrow colony culture, bone marrow cell flow cytometry, peripheral blood T cell subsets, and serum inflammatory cytokines tests were performed on d14. Transcriptome sequencing was performed for cells from CsA + UC-MSC, CsA + UCB-Treg, and CsA groups to detect the possible related genes. Gene function cluster and signal pathway enrichment analysis were also performed.

Results

Blank control mice died due to pancytopenia within 21 days, whereas mice in other groups survived for >28 days. On d14, the CsA + UC-MSC and CsA + UCB-Treg groups had higher white blood cell (WBC) counts than the other groups (p < 0.05), along with higher burst-forming unit (BFU) and colony-forming unit-granulocyte, macrophage (CFU-GM) counts (p < 0.01). The CsA + UC-MSC group had the highest BFU count (p < 0.01). The CsA + UC-MSC and CsA + UCB-Treg groups exhibited the highest bone marrow CD34+ cell proportion (9.68% ± 1.35% and 8.17% ± 0.53%, respectively; p < 0.01). Tumor necrosis factor (TNF)-α and interleukin (IL)-2 levels in the CsA + UC-MSC group (p < 0.05) and TNF-α, interleukin-2, and interferon (INF)-γ levels in the CsA + UC-Treg group (p < 0.01) were lower than those in the CsA group. Compared with CsA treatment, CsA + UC-MSC significantly downregulated the histone methylation pathway (p < 0.05), whereas CsA + UCB-Treg significantly upregulated energy metabolism processes (p < 0.05). Treatment with CsA + UC-MSC upregulated superoxide dismutase activity compared with CsA + UCB-Treg treatment.

Conclusions

Adding UC-MSC or UCB-Treg to CsA markedly enhanced the reconstruction of hematopoiesis in AA mice, with UC-MSC eliciting greater efficiency than UCB-Treg. Accordingly, the addition of these cells could further improve immune abnormalities.

Downregulation of histone-lysine N-methyltransferase EZH2 inhibits cell viability and enhances chemosensitivity in lung cancer cells

Histone-lysine N-methyltransferase EZH2 (EZH2) is the principle component of the polycomb repressive complex 2 (PRC2)/embryonic ectoderm development protein-EZH2 complex, which promotes tumorigenesis by repressing transcription of tumor suppressor genes. EZH2 is considered a key marker in several types of cancer, such as colorectal and prostate cancer. However, the molecular mechanisms and clinical value of EZH2 in lung cancer have not yet been fully investigated. The aim of the present study was to investigate the functions of EZH2 in lung cancer progression and to determine whether treatment with an EZH2 inhibitor enhanced the chemosensitivity of lung cancer cells to cisplatin (CDDP). At the logarithmic growth phase, A549 cells were treated with a small interfering (si)RNA-EZH2, and cell viability was detected using an MTT assay. The degree of apoptosis and cell cycle were detected using flow cytometry. Cell migration and invasion were detected via wound healing and Transwell Matrigel assays. According to information from the Gene Expression Omnibus database, the results of the present study demonstrated that EZH2 was upregulated in lung cancer. Furthermore, overexpression of EZH2 was associated with poor patient prognosis, while EZH2 knockdown inhibited cell viability and migration, and enhanced apoptosis and chemosensitivity in a lung cancer cell line. EZH2 knockdown and treatment of A549 cells using EZH2 inhibitor elevated the inhibitory effects of CDDP on cell viability and apoptosis. Western blot and reverse transcription-quantitative PCR analyses were performed to assess the expression levels of relative protein and mRNA, respectively, in A549 cells treated with siRNA-EZH2 or with CDDP. Overall, the results of the present study demonstrated that high EZH2 expression was associated with poor prognosis, accompanied with a potential impairment of migration and viability in lung cancer cells. These findings suggest that EZH2 may act as a candidate molecular target for gene therapy, and treatment with EZH2 inhibitor may be used to increase chemosensitivity to CDDP agents in lung cancer.

Chromatin-modifying drugs and metabolites in cell fate control

For multicellular organisms, it is essential to produce a variety of specialized cells to perform a dazzling panoply of functions. Chromatin plays a vital role in determining cellular identities, and it dynamically regulates gene expression in response to changing nutrient metabolism and environmental conditions. Intermediates produced by cellular metabolic pathways are used as cofactors or substrates for chromatin modification. Drug analogues of metabolites that regulate chromatin-modifying enzyme reactions can also regulate cell fate by adjusting chromatin organization. In recent years, there have been many studies about how chromatin-modifying drug molecules or metabolites can interact with chromatin to regulate cell fate. In this review, we systematically discuss how DNA and histone-modifying molecules alter cell fate by regulating chromatin conformation and propose a mechanistic model that explains the process of cell fate transitions in a concise and qualitative manner.

Impact of neural stem cell-derived extracellular vesicles on mitochondrial dysfunction, sirtuin 1 level, and synaptic deficits in Alzheimer's disease

Small extracellular vesicles (EVs), including exosomes, play multiple physiological roles. In neurodegenerative diseases, EVs can be pivotal in dispersing neuropathogenic proteins. This study investigates the role of neural stem cell (NSC)-derived EVs in a transgenic (Tg) mouse model of Alzheimer's disease (AD). Five weeks following treatment on 9-month-old APP/PS1 mice, the effects of NSC-derived EVs on cognitive behavior, mitochondrial function, sirtuin1 (SIRT1), synaptic function and morphology, quantification of amyloid-β (Aβ) level, and inflammatory response were investigated. The results showed that mice in the Tg-NSCs-ev group exhibited significant improvement in cognitive performance compared with Tg-Veh group. Furthermore, the expression of mitochondrial function-related factors (peroxisome proliferator-activated receptor-γ coactivator-1α [PGC1α], nuclear respiratory factor 1 and 2 [NRF1 and 2], and fission 1 [Fis1]), SIRT1 as well as synaptic proteins (growth-associated protein 43 [GAP43], synaptophysin [SYP], post-synaptic density 95 [PSD95] and microtubule-associated protein 2 [MAP2]) were significantly higher in the Tg-NSCs-ev group, when compared with the Tg-Veh group. In addition, oxidative damage markers (anti-4-Hydroxynonenal [4-HNE] and anti-3 nitrotyrosine [3-NT]), inflammatory cytokines and the microglial marker (Iba1) were significantly lower in the Tg-NSCs-ev group, compared to the Tg-Veh group. Moreover, synaptic morphology was distinctly improved in the Tg-NSCs-ev group, whereas the Aβ level was not altered. Our study provides novel evidences that NSC-derived EVs enhanced mitochondrial function, SIRT1 activation, synaptic activity, decreased inflammatory response, and rescued cognitive deficits in AD like mice.