The Protective Effects of γ-Tocotrienol on Muscle Stem Cells Through Inhibiting Reactive Oxidative Stress Production.

Pseudotrophic muscular dystrophy is a common clinical skeletal muscle necrotic disease, among which Duchenne muscular dystrophy (DMD) is the predominant. For such diseases, there is no clinically effective treatment, which is only symptomatic or palliative treatment. Oxidative stress and chronic inflammation are common pathological features of DMD. In recent years, it has been found that the pathophysiological changes of skeletal muscle in DMD mice are related to muscle stem cell failure. In the present study, we established a DMD mice model and provided tocotrienol (γ-tocotrienol, GT3), an antioxidant compound, to explore the relationship between the physiological state of muscle stem cells and oxidative stress. The results showed that the application of GT3 can reduce ROS production and cellular proliferation in the muscle stem cells of DMD mice, which is beneficial to promote the recovery of muscle stem cell function in DMD mice. GT3 treatment improved the differentiation ability of muscle stem cells in DMD mice with increasing numbers of MyoD+ cells. GT3 application significantly decreased percentages of CD45+ cells and PDGFRα+ fibro-adipogenic progenitors in the tibialis anterior of DMD mice, indicating that the increased inflammation and fibro-adipogenic progenitors were attenuated in GT3-treated DMD mice. These data suggest that increased ROS production causes dysfunctional muscle stem cell in DMD mice, which might provide a new avenue to treat DMD patients in the clinic.

Identification of hub genes, miRNAs and regulatory factors relevant for Duchenne muscular dystrophy by bioinformatics analysis.

PURPOSE: Duchenne muscular dystrophy (DMD) is currently the most commonly diagnosed form of muscular dystrophy due to mutations in the dystrophin gene. However, its pathological process remains unknown and there is a lack of specific molecular biomarkers. The aim of our study is to explore key regulatory connections underlying the progression of DMD. MATERIALS AND METHODS: The gene expression profile dataset GSE38417 of DMD was obtained from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between DMD patients and healthy controls were screened using geo2R, followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathway enrichment analyses. Then a protein-protein interaction (PPI) network and sub-network of modules were constructed. To investigate the regulatory network underlying DMD, a global triple network including miRNAs, mRNAs and transcription factors (TFs) was constructed. RESULTS: A total of 1811 DEGs were found between the DMD and control groups, among which HERC5, SKP2 and FBXW5 were defined as hub genes with a degree of connectivity >35 in the PPI network. Furthermore, the five TFs ZNF362, ATAT1, SPI1, TCF12 and ABCF2, as well as the eight miRNAs miR-124a, miR-200b/200c/429, miR-19a/b, miR-23a/b, miR-182, miR-144, miR-498 and miR-18a/b were identified as playing crucial roles in the molecular pathogenesis of DMD. CONCLUSIONS: This paper provides a comprehensive perspective on the miRNA-TF-mRNA co-regulatory network underlying DMD, although the bioinformatic findings need further validation in future studies.

Identifying Hub Genes, Key Pathways and Immune Cell Infiltration Characteristics in Pediatric and Adult Ulcerative Colitis by Integrated Bioinformatic Analysis.

BACKGROUND AND AIMS: In the present study, we investigated the differentially expressed genes (DEGs), pathways and immune cell infiltration characteristics of pediatric and adult ulcerative colitis (UC). METHODS: We conducted DEG analysis using the microarray dataset GSE87473 containing 19 pediatric and 87 adult UC samples downloaded from the Gene Expression Omnibus. Gene ontology and pathway enrichment analyses were conducted using Metascape. We constructed the protein-protein interaction (PPI) network and the drug-target interaction network of DEGs and identified hub modules and genes using Cytoscape and analyzed immune cell infiltration in pediatric and adult UC using CIBERSORT. RESULTS: In total, 1700 DEGs were screened from the dataset. These genes were enriched mainly in inter-cellular items relating to cell junctions, cell adhesion, actin cytoskeleton and transmembrane receptor signaling pathways and intra-cellular items relating to the splicing, metabolism and localization of RNA. CDC42, POLR2A, RAC1, PIK3R1, MAPK1 and SRC were identified as hub DEGs. Immune cell infiltration analysis revealed higher proportions of naive B cells, resting memory T helper cells, regulatory T cells, monocytes, M0 macrophages and activated mast cells in pediatric UC, along with lower proportions of memory B cells, follicular helper T cells, γδ T cells, M2 macrophages, and activated dendritic cells. CONCLUSIONS: Our study suggested that hub genes CDC42, POLR2A, RAC1, PIK3R1, MAPK1 and SRC and immune cells including B cells, T cells, monocytes, macrophages and mast cells play vital roles in the pathological differences between pediatric and adult UC and may serve as potential biomarkers in the diagnosis and treatment of UC.

The oncogenic role of Jagged1/Notch signaling in cancer.

Aberrant activation of Notch signaling plays an oncogenic role in cancer development. Jagged1 (JAG1) is an important Notch ligand that triggers Notch signaling through cell-cell interactions. JAG1 overexpression has been reported in many different types of cancer and correlates with a poor clinical prognosis. JAG1/Notch signaling controls oncogenic processes in different cell types and cellular contexts. Furthermore, JAG1/Notch signaling cascades activate a number of oncogenic factors that regulate cellular functions such as proliferation, metastasis, drug-resistance, and angiogenesis. To suppress the severe toxicity of pan-Notch inhibitors, JAG1 is attracting increasing attention as a source of therapeutic targets for cancers. In this review, the oncogenic role of JAG1/Notch signaling in cancer is discussed, as well as implications of strategies to inhibit JAG1/Notch signaling activity.

The Role of DLLs in Cancer: A Novel Therapeutic Target.

Delta-like ligands (DLLs) control Notch signaling. DLL1, DLL3 and DLL4 are frequently deregulated in cancer and influence tumor growth, the tumor vasculature and tumor immunity, which play different roles in cancer progression. DLLs have attracted intense research interest as anti-cancer therapeutics. In this review, we discuss the role of DLLs in cancer and summarize the emerging DLL-relevant targeting methods to aid future studies.

Isoprenaline protects intestinal stem cells from chemotherapy-induced damage.

BACKGROUND AND PURPOSE: Damage to intestinal epithelial cells and mucosa limits the effectiveness of several anti-cancer chemotherapeutic agents but the underlying mechanism (s) remain unknown. Little is known of how enteric nervous system regulates proliferation, differentiation, impairment, and regeneration of intestinal stem cells. Here we have investigated the effects of isoprenaline on the damaged intestinal stem cells induced by chemotherapeutic treatments in mice. EXPERIMENTAL APPROACH: The effects of inhibiting sympathetic and parasympathetic nerves on intestinal stem cells were examined in male C57BL/6J mice. Protection by isoprenaline of intestinal stem cells was assessed in the presence or absence of 5-fluorouracil (5FU) or cisplatin. Cellular apoptosis, cell cycle, PI3K/Akt signalling, and NF-κB signalling in intestinal stem cells were mechanistically evaluated. KEY RESULTS: The sympathetic nerve inhibitor 6-OHDA decreased the number and function of intestinal stem cells. 5FU or cisplatin treatment damaged both intestinal stem cells and sympathetic nerves. Notably, isoprenaline accelerated the recovery of intestinal stem cells after 5FU or cisplatin treatment. This protective effect of isoprenaline on damaged intestinal stem cells was mediated by ß2 -adrenoceptors. The benefits of isoprenaline were mainly mediated by inhibiting cellular apoptosis induced by 5FU treatment, which might contribute to fine-tuning regulating NF-κB signalling pathway by isoprenaline administration. CONCLUSIONS AND IMPLICATIONS: Treatment with isoprenaline is a new approach to ameliorate the damage to intestinal stem cells following exposure to cancer chemotherapeutic agents.

Transient Inhibition of mTORC1 Signaling Ameliorates Irradiation-Induced Liver Damage.

Recurrent liver cancer after surgery is often treated with radiotherapy, which induces liver damage. It has been documented that activation of the TGF-ß and NF-κB signaling pathways plays important roles in irradiation-induced liver pathologies. However, the significance of mTOR signaling remains undefined after irradiation exposure. In the present study, we investigated the effects of inhibiting mTORC1 signaling on irradiated livers. Male C57BL/6J mice were acutely exposed to 8.0 Gy of X-ray total body irradiation and subsequently treated with rapamycin. The effects of rapamycin treatment on irradiated livers were examined at days 1, 3, and 7 after exposure. The results showed that 8.0 Gy of irradiation resulted in hepatocyte edema, hemorrhage, and sinusoidal congestion along with a decrease of ALB expression. Exposure of mice to irradiation significantly activated the mTORC1 signaling pathway determined by pS6 and p-mTOR expression via western blot and immunostaining. Transient inhibition of mTORC1 signaling by rapamycin treatment consistently accelerated liver recovery from irradiation, which was evidenced by decreasing sinusoidal congestion and increasing ALB expression after irradiation. The protective role of rapamycin on irradiated livers might be mediated by decreasing cellular apoptosis and increasing autophagy. These data suggest that transient inhibition of mTORC1 signaling by rapamycin protects livers against irradiation-induced damage.

Inhibition of mTORC1 signaling protects kidney from irradiation-induced toxicity via accelerating recovery of renal stem-like cells.

BACKGROUND: Irradiation-induced kidney damage is inevitable during radiotherapeutic practice, which limits effective radiotherapy doses on tumor treatment. In the present study, the role of mTOR complex 1 (mTORC1) signaling was investigated in irradiation-induced renal injuries. METHODS: Mice were exposed to 8.0-Gy X-ray of total body irradiation and subsequently treated with rapamycin. Changes of renal morphology were assessed by hematoxylin and eosin staining. Expression of pS6 and CD133 was detected via immunostaining. Cellular apoptosis and proliferation were measured by TUNEL, caspase-3 and BrdU staining. Activation of mTORC1, TGF-ß and NF-κB signaling pathways was determined through western blot analysis. RESULTS: Our data displayed that irradiation disrupted the structures of renal corpuscles and tubules and decreased the density of CD133+ renal stem-like cells, which were related with increasing cellular apoptosis and decreasing cell proliferation post exposure. Activation of mTORC1, TGF-ß and NF-κB signaling pathways was determined in irradiated renal tissues, which were inhibited by rapamycin treatment. Application of rapamycin after irradiation decreased cellular apoptosis and increased autophagy and cell proliferation in renal tissues. The density of CD133+ renal stem-like cells was significantly increased in irradiated kidneys after rapamycin treatment. The morphology of irradiated renal corpuscles and tubules was gradually recovered upon rapamycin treatment. CONCLUSIONS: These findings indicate that inhibition of mTORC1 signaling by rapamycin ameliorates irradiation-induced renal toxicity mediated by decreasing cellular apoptosis and increasing CD133+ renal stem-like cells.

Droxinostat sensitizes human colon cancer cells to apoptotic cell death via induction of oxidative stress.

Upregulation of histone acetylation plays a critical role in the dysregulation of transcription. It alters the structure of chromatin, which leads to the onset of cancer. Histone deacetylase inhibitors may therefore be a promising way to limit cancer progression. In this study, we examined the effects of droxinostat on the growth of HT-29 colon cancer cells. Our results show that droxinostat effectively inhibited cell growth and colony-forming ability by inducing cellular apoptosis and ROS production in HT-29 cells. Notably, the apoptotic inhibitor Z-VAD-FMK significantly decreased the levels of cellular apoptosis and the antioxidant γ-tocotrienol (GT3) significantly decreased ROS production induced by droxinostat treatment. Z-VAD-FMK and GT3 also partially reversed the negative growth effects of droxinstat on HT-29 cells. GT3 treatment decreased cellular apoptosis and increased colony-forming ability upon droxinostat administration. Z-VAD-FMK treatment also partially decreased droxinostat-induced ROS production. Our findings suggest that the effects of droxinostat on colon cancer cells are mediated by the induction of oxidative stress and apoptotic cell death.

[Single nucleotide polymorphism of miR-149 and susceptibility of rheumatoid arthritis].

OBJECTIVE: To investigate the association between microRNA (miR)-149 polymorphism and susceptibility to rheumatoid arthritis (RA ), as well as the clinical characteristics in patients with RA . METHODS: A total of 200 RA patients and 120 healthy controls were recruited from Department of Rheumatology and Immunology of Nanjing First Hospital. After obtaining the informed consent, we collected 2 mL of anti-coagulated venous blood samples from all studied subjects to isolate the whole blood genomic DNA, and the clinical data were collected as well. Single nucleotide polymorphisms of miR-149 rs22928323 were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Correlation between single nucleotide polymorphisms and clinical features were compared. RESULTS: The frequencies of TT, TC and CC for rs22928323 of miR-149 were 25.3%, 51.1% and 23.6% or 18.3%, 20.0% and 61.7% in the patients or the healthy controls, respectively. The onset risk of allele C in RA patients was increased compared with allele T [OR=1.38, 95% CI (1.01-1.75), P=0.023]. There were no significant difference in rheumatoid factor, blood urine nitrogen, antikeratin antibody, and other clinical characteristics among the 3 genotypes in RA patients (P>0.05). CONCLUSION: SNP rs22928323 in miR-149 is correlated with RA in the east of Chinese Han population, whereas there is no correlation between miR-149 polymorphism and clinical characteristics in patients with RA.