Evaluating the antioxidant potential of resveratrol-gold nanoparticles in preventing oxidative stress in endothelium on a chip.

Vascular endothelial cells play a vital role in the health and maintenance of vascular homeostasis, but hyperglycemia disrupts their function by increasing cellular oxidative stress. Resveratrol, a plant polyphenol, possesses antioxidant properties that can mitigate oxidative stress. Addressing the challenges of its limited solubility and stability, gold nanoparticles (GNps) were utilized as carriers. A microfluidic chip (MFC) with dynamic flow conditions was designed to simulate body vessels and to investigate the antioxidant properties of resveratrol gold nanoparticles (RGNps), citrate gold nanoparticles (CGNps), and free Resveratrol on human umbilical vein endothelial cells (HUVEC). The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay was employed to measure the extracellular antioxidant potential, and cell viability was determined using the Alamar Blue test. For assessing intracellular oxidative stress, the 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) assay was conducted, and results from both the cell culture plate and MFC were compared. Free Resveratrol demonstrated peak DPPH scavenging activity but had a cell viability of about 24-35%. RGNPs, both 3.0 ± 0.5 nm and 20.2 ± 4.7 nm, consistently showed high cell viability (more than about 90%) across tested concentrations. Notably, RGNPs (20 nm) exhibited antioxidative properties through DPPH scavenging activity (%) in the range of approximately 38-86% which was greater than that of CGNps at about 21-32%. In the MFC,the DCFH-DA analysis indicated that RGNPs (20 nm) reduced cellular oxidative stress by 57-82%, surpassing both CGNps and free Resveratrol. Morphologically, cells in the MFC presented superior structure compared to those in traditional cell culture plates, and the induction of hyperglycemia successfully led to the formation of multinucleated variant endothelial cells (MVECs). The MFC provides a distinct advantage in observing cell morphology and inducing endothelial cell dysfunction. RGNps have demonstrated significant potential in alleviating oxidative stress and preventing endothelial cell disorders.

Impact of curcumin on ferroptosis-related genes in colorectal cancer: Insights from in-silico and in-vitro studies.

Colorectal cancer (CRC) is responsible for a significant number of cancer-related fatalities worldwide. Researchers are investigating the therapeutic potential of ferroptosis, a type of iron-dependent controlled cell death, in the context of CRC. Curcumin, a natural compound found in turmeric, exhibits anticancer properties. This study explores the effects of curcumin on genes related to ferroptosis (FRGs) in CRC. To gather CRC data, we used the Gene Expression Profiling Interactive Analysis (GEPIA) and Gene Expression Omnibus (GEO) databases, while FRGs were obtained from the FerrDb database and PubMed. We identified 739 CRC differentially expressed genes (DEGs) in CRC and discovered 39 genes that were common genes between FRGs and CRC DEGs. The DEGs related to ferroptosis were enriched with various biological processes and molecular functions, including the regulation of signal transduction and glucose metabolism. Using the Drug Gene Interaction Database (DGIdb), we predicted drugs targeting CRC-DEGs and identified 17 potential drug targets. Additionally, we identified eight essential proteins related to ferroptosis in CRC, including MYC, IL1B, and SLC1A5. Survival analysis revealed that alterations in gene expression of CDC25A, DDR2, FABP4, IL1B, SNCA, and TFAM were associated with prognosis in CRC patients. In SW480 human CRC cells, treatment with curcumin decreased the expression of MYC, IL1B, and EZH2 mRNA, while simultaneously increasing the expression of SLCA5 and CAV1. The findings of this study suggest that curcumin could regulate FRGs in CRC and have the potential to be utilized as a therapeutic agent for treating CRC.

Mesenchymal stem cell-derived exosomes enriched with miR-218 reduce the epithelial-mesenchymal transition and angiogenesis in triple-negative breast cancer cells.

BACKGROUND: The epithelial-mesenchymal transition (EMT) and angiogenesis are morphogenetic processes implicated in tumor invasion and metastasis. It is found that the aberrant expression of microRNAs (miRNAs) contributes to these processes. Exosomes are considered potential natural vehicles for miRNA delivery in cancer therapy. miR-218 is one of the tumor suppressor miRNAs and its downregulation is associated with EMT and angiogenesis. We aimed to use adipose mesenchymal stem cells-derived exosomes (ADMSC-exosomes) for miR-218 delivery to breast cancer cells and evaluate miR-218 tumor-suppressing properties in vitro. METHODS: Exosomes were isolated from conditioned media of ADMSCs. miR-218 was loaded to exosomes using electroporation. mRNA expression of target genes (Runx2 and Rictor) in MDA-MB-231 breast cancer cells was evaluated by qPCR. To explore the effects of miR-218 containing exosomes on breast cancer cells, viability, apoptosis, and Boyden chamber assays were performed. The angiogenic capacity of MDA-MB-231 cells after treatment with miR-218 containing exosomes was assessed by in vitro tube formation assay. RESULTS: miR-218 mimic was efficiently loaded to ADMSC-exosomes and delivered to MDA-MB-231 cells. Exposure to miR-218 containing exosomes significantly decreased miR-218 target genes (Runx2 and Rictor) in MDA-MB-231 cells. They increased the expression of epithelial marker (CDH1) and reduced mesenchymal marker (CDH2). miR-218 restoration using miR-218 containing exosomes reduced viability, motility, invasion, and angiogenic capacity of breast cancer cells. CONCLUSIONS: These findings suggest that ADMSC-exosomes can efficiently restore miR-218 levels in breast cancer cells and miR-218 can prevent breast cancer progression with simultaneous targeting of angiogenesis and EMT.

Identification of co-regulated genes associated with doxorubicin resistance in the MCF-7/ADR cancer cell line.

Introduction: The molecular mechanism of chemotherapy resistance in breast cancer is not well understood. The identification of genes associated with chemoresistance is critical for a better understanding of the molecular processes driving resistance. Methods: This study used a co-expression network analysis of Adriamycin (or doxorubicin)-resistant MCF-7 (MCF-7/ADR) and its parent MCF-7 cell lines to explore the mechanisms of drug resistance in breast cancer. Genes associated with doxorubicin resistance were extracted from two microarray datasets (GSE24460 and GSE76540) obtained from the Gene Expression Omnibus (GEO) database using the GEO2R web tool. The candidate differentially expressed genes (DEGs) with the highest degree and/or betweenness in the co-expression network were selected for further analysis. The expression of major DEGs was validated experimentally using qRT-PCR. Results: We identified twelve DEGs in MCF-7/ADR compared with its parent MCF-7 cell line, including 10 upregulated and 2 downregulated DEGs. Functional enrichment suggests a key role for RNA binding by IGF2BPs and epithelial-to-mesenchymal transition pathways in drug resistance in breast cancer. Discussion: Our findings suggested that MMP1, VIM, CNN3, LDHB, NEFH, PLS3, AKAP12, TCEAL2, and ABCB1 genes play an important role in doxorubicin resistance and could be targeted for developing novel therapies by chemical synthesis approaches.

Exosomal delivery of 7SK long non-coding RNA suppresses viability, proliferation, aggressiveness and tumorigenicity in triple negative breast cancer cells.

AIMS: RN7SK (7SK), a highly conserved non-coding RNA, serves as a transcription regulator via interaction with a few proteins. Despite increasing evidences which support the cancer-promoting roles of 7SK-interacting proteins, limited reports address the direct link between 7SK and cancer. To test the hypothetic suppression of cancer by overexpression of 7SK, the effects of exosomal 7SK delivery on cancer phenotypes were studied. MATERIALS AND METHODS: Exosomes derived from human mesenchymal stem cells were loaded with 7SK (Exo-7SK). MDA-MB-231, triple negative breast cancer (TNBC), cell line was treated with Exo-7sk. Expression levels of 7SK were evaluated by qPCR. Cell viability was assessed via MTT and Annexin V/PI assays as well as qPCR assessment of apoptosis-regulating genes. Cell proliferation was evaluated by growth curve analysis, colony formation and cell cycle assays. Aggressiveness of TNBCs was evaluated via transwell migration and invasion assays and qPCR assessment of genes regulating epithelial to mesenchymal transition (EMT). Moreover, tumor formation ability was assessed using a nude mice xenograft model. KEY FINDINGS: Treatment of MDA-MB-231 cells with Exo-7SK resulted in efficient overexpression of 7SK; reduced viability; altered transcription levels of apoptosis-regulating genes; reduced proliferation; reduced migration and invasion; altered transcription of EMT-regulating genes; and reduced in vivo tumor formation ability. Finally, Exo-7SK reduced mRNA levels of HMGA1, a 7SK interacting protein with master gene regulatory and cancer promoting roles, and its bioinformatically-selected cancer promoting target genes. SIGNIFICANCE: Altogether, as a proof of the concept, our findings suggest that exosomal delivery of 7SK may suppress cancer phenotypes via downregulation of HMGA1.

Screening and introduction of key cell cycle microRNAs deregulated in colorectal cancer by integrated bioinformatics analysis.

Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men worldwide. Impaired cell cycle regulation leads to many cancers and is also approved in CRC. Therefore, cell cycle regulation is a critical therapeutic target for CRC. Furthermore, miRNAs have been discovered as regulators in a variety of cancer-related pathways. This study is designed to investigate how miRNAs and mRNAs interact to regulate the cell cycle in CRC patients. Utilizing the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Expression Omnibus (GEO), and Therapeutic Target Database (TTD), cell cycle-associated genes were identified and evaluated. Seven of the 22 differentially expressed genes (DEGs) implicated in the cell cycle in three GSEs (GSE24514, GSE10950, and GSE74604) were identified as potential therapeutic targets. Then, using PyRx software, we performed docking proteins with selected drugs. The results demonstrated that these drugs are appropriate molecules for targeting cell cycle DEGs. Tarbase, miRTarbase, miRDIP, and miRCancer databases were used to find miRNAs that target the indicated genes. The ability of these six miRNAs to impact the cell cycle in colorectal cancer may be concluded. These miRNAs were found to be downregulated in SW480 cells when compared to the normal tissue. Our data imply that a precise selection of bioinformatics tools can facilitate the identification of miRNAs that impact mRNA translation at different stages of the cell cycle. The candidates can be investigated more as targets for cell cycle arrest in cancers.

Neuroprotective effects of niosomes loaded with thymoquinone in the cerebral ischemia model of male Wistar rats.

The complex stroke pathophysiology, like oxidative stress and inflammatory reactions, causes substantially challenged in stroke treatment. Thymoquinone (TQ) is attributed to pharmacological actions like antioxidant and anti-inflammation. Thymoquinone is chemically hydrophobic, which causes poor solubility and bioavailability. To overcome this challenge Thymoquinone niosome was applied in this in-vivo study. The results demonstrated a significant reduction in rats treated with Thymoquinone niosome compared to free Thymoquinone and control groups (SOD), (TAC), and (GPX) activities were increased in the TQN group compared to the MCAO control group. The decrease in (MDA) level was seen in the Thymoquinone niosome group compared to the MCAO control group. The inflammation factors expression rates of IL-IB, IL-6, TNFα in I/R Thymoquinone niosome group were decreased. This study indicated that Thymoquinone niosome might be utilized as a promising novel carrier to improve Thymoquinone bioavailability and therapeutic effect in treating cerebral I/R injury.

Inhibitory Effects of Dutasteride on TLR4: An In vitro Pain Study.

Dutasteride was potentially proposed to control chronic pain by Toll-Like Receptor 4 (TLR4) inhibition through its effect on TLR4 expression, Myeloid differentiation primary response 88 (MyD88), Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), secretory Interleukin-1ß (IL-1ß), and nitric oxide (NO) in the Lipopolysaccharides (LPS)-stimulated U-87 MG cell line. Human astrocytoma U-87 MG cell line was cultured and incubated with 10 µg/mL of LPS for 24 hours to create a neuro-inflammation model, using two different treatment approaches. The first approach included LPS treatment for 24 hours, followed by dutasteride (20 µg/mL) incubation for the next 72 hours. In the second treatment approach, the cells were co-incubated with LPS and dutasteride for 72 hours. Expression of TLR4, MyD88, NF-κBp65, and secretory IL-1 was evaluated by Western blotting while expression of NO was assessed by NO assay. TLR4, MyD88, NF-κBp65, and secretory IL-1ß levels increased in LPS-treated cells after 24 hours. Dutasteride significantly decreased the secretion of NO and also, the levels of TLR4, MyD88, and NF-κBp65 in both treatment approaches. No difference in IL-1ß level was seen with the second treatment approach. Dutasteride has anti-inflammatory properties and probably analgesic effects, by mechanisms different from conventional analgesics.

RNAa-mediated epigenetic attenuation of the cell senescence via locus specific induction of endogenous SIRT1.

SIRT1, a known regulator of cellular senescence, is a therapeutic target for age related disorders and its upregulation is a strategy to improve the cell therapeutic potentials of human mesenchymal stem cell (MSCs). Knockdown of natural antisense transcripts via small activating RNAs (RNAa) is an emerging approach for safe and locus specific gene regulation. We have recently identified a natural antisense transcript at human SIRT1 locus (SIRT1-NAT), the expression of which shows a negative correlation with that of SIRT1. To test the hypothetic upregulation of SIRT1 via knockdown of SIRT1-NAT, in this study we designed a single stranded oligonucleotide (SIRT1-antagoNAT) against the antisense transcript, transfection of which efficiently knocked down the SIRT1-NAT and induced SIRT1 transcription in human MSCs. In addition, activation of SIRT1 transfection via knockdown of SIRT1-NAT in human MSCs enhanced their proliferation and differentiation potentials, reduced senescence associated ß-galactosidase activity and reversed the senescence associated molecular alterations. Our findings introduce an RNAa mediated approach for epigenetic induction of endogenous SIRT1 and the consequent attenuation of senescence. Further studies should evaluate the therapeutic potentials of this approach against various age related disorders.

Effects of Wound Fluid on Breast Cancer-derived Spheroids in a 3D Culture System: A Case Series Study.

Surgery is the standard treatment for breast malignancies, although local and distant relapses might occur. Previous studies have shown that surgery-induced wound fluid (WF) contains tumor-initiating and progressing factors; however, these experiments have only been performed on breast cancer cell lines. Since a cancerous tumor includes various components like malignant cells, recruited non-malignant cells and extracellular matrix, those investigations that only focused on cancer cell lines themselves are not adequate to establish WF's effects. We conducted a 3D model study where we mimicked the tumor microenvironment to re-assess previous in-vitro findings. We generated human-derived breast tumor spheroids from 23 patient specimens, dissociated and cultured them in microfluidic devices. The spheroids from each sample were treated with the patients' WF or RPMI medium. The proportion of live and dead cells was assessed using live/dead assays and fluorescent imaging on day 6. In 22 samples, the percentage of live cells was significantly higher in the WF-treated group than in the RPMI-treated group. In one sample, we observed an opposite trend. The results were contrary in one of the samples, and we reported that case with more details. We compared the two groups using the 3D culture environment of human-derived tumor spheroids prepared from different microfluidic devices to mimic the tumor environment heterogeneity. Our findings showed that most patients with breast cancer benefit from surgical wound healing. However, removal of the surgical-induced serum may not be a method of inhibiting the tumor in all patients.

Radiobiological effects of wound fluid on breast cancer cell lines and human-derived tumor spheroids in 2D and microfluidic culture.

Intraoperative radiotherapy (IORT) could abrogate cancer recurrences, but the underlying mechanisms are unclear. To clarify the effects of IORT-induced wound fluid on tumor progression, we treated breast cancer cell lines and human-derived tumor spheroids in 2D and microfluidic cell culture systems, respectively. The viability, migration, and invasion of the cells under treatment of IORT-induced wound fluid (WF-RT) and the cells under surgery-induced wound fluid (WF) were compared. Our findings showed that cell viability was increased in spheroids under both WF treatments, whereas viability of the cell lines depended on the type of cells and incubation times. Both WFs significantly increased sub-G1 and arrested the cells in G0/G1 phases associated with increased P16 and P21 expression levels. The expression level of Caspase 3 in both cell culture systems and for both WF-treated groups was significantly increased. Furthermore, our results revealed that although the migration was increased in both systems of WF-treated cells compared to cell culture media-treated cells, E-cadherin expression was significantly increased only in the WF-RT group. In conclusion, WF-RT could not effectively inhibit tumor progression in an ex vivo tumor-on-chip model. Moreover, our data suggest that a microfluidic system could be a suitable 3D system to mimic in vivo tumor conditions than 2D cell culture.

Delivery of miR-381-3p Mimic by Mesenchymal Stem Cell-Derived Exosomes Inhibits Triple Negative Breast Cancer Aggressiveness; an In Vitro Study.

Recent investigations have emphasized the role of aberrant expression of microRNAs (miRNAs) in progression of almost all types of cancers. Exosomes, membrane-enclosed natural nanovesicles, transport cellular contents, including proteins, mRNAs, and miRNAs, between cells. Unique features of exosomes make them an appropriate carrier for drug delivery. miRNA-381 is one of the downregulated miRNAs in several cancers including triple-negative breast cancer (TNBC) and restoration of its expression in TNBC cells can restrict their migratory ability through targeting several signaling pathways. In current study, we exploited the exosomes isolated from adipose-derived mesenchymal stem cells (ADMSC-exosomes) to deliver miR-381 mimic to MDA-MB-231 cells to elucidate their effects on TNBC cells. The effects of miR-381 loaded ADMSC-exosomes on proliferation, apoptosis, migration, and invasion of MDA-MB-231 cells were analyzed. Our results indicated that ADMSC-exosomes were successfully isolated and internalized by MDA-MB-231 cells. miR-381 mimic was efficiently delivered to MDA-MB-231 cells by ADMSC-exosomes. miR-381 loaded ADMSC-exosomes significantly downregulated the expression of epithelial to mesenchymal transition (EMT) related genes and proteins. Notably, miR-381 loaded ADMSC-exosomes inhibited proliferation, migration, and invasion capacity of MDA-MB-231 and promoted their apoptosis in vitro. Taken together, we showed that ADMSC-exosomes could be used as efficient nanocarriers for RNA-based therapies. Graphical abstract.

Fatty Acid Binding Protein 7 is Involved in the Proliferation of Reactive Astrocytes, but not in Cell Migration and Polarity.

Reactive gliosis is a defense mechanism to minimize and repair the initial damage after CNS injuries that is characterized by increases in astrocytic reactivity and proliferation, with enhanced expression of glial fibrillary acidic protein (GFAP) and cellular hypertrophy. Fatty acid binding protein 7 (FABP7) is abundantly expressed in several types of glial cells, such as astrocytes and oligodendrocyte precursor cells, during brain development and FABP7-positive astrocytes have been shown to be significantly increased in the mouse cortex after a stab injury. However, the functional significance of FABP7 in gliosis remains unclear. In the present study, we examined the mechanism of FABP7-mediated regulation of gliosis using an in vitro scratch-injury model using primary cultured astrocytes. Western blotting showed that FABP7 expression was increased significantly in scratch wounded astrocytes at the edge of the injury compared with intact astrocytes. Through monitoring the occupancy of the injured area, FAB7-KO astrocytes showed a slower proliferation rate compared with WT astrocytes after 48 hr, which was confirmed by BrdU immunostaining. There were no differences in cell migration and polarity of reactive astrocytes between FABP-KO and WT. Conclusively, our data suggest that FABP7 is important in the proliferation of reactive astrocytes in the context of CNS injury.

Adipose derived mesenchymal stem cell exosomes loaded with miR-10a promote the differentiation of Th17 and Treg from naive CD4+ T cell.

AIMS: The balance between various CD4+ T cell subsets through highly regulated differentiation of naïve T cells is critical to ensure proper immune response, disruption of which may cause autoimmunity and cancers. miR-10a has been reported to regulate the fate of naïve T cells. Mesenchymal stem cells (MSC) derived exosomes are known effective immunomodulators and ideal vehicles for delivery of microRNAs. This study was aimed to examine the impacts of miR-10a on CD4+ cell fate upon exosomal delivery in combination with immunomodulatory effects of MSCs. MAIN METHODS: Exosomes isolated form adipose tissue derived mesenchymal stem cells (AD-MSC-Exo) were transfected with miR-10a and added to naïve T cells purified from mouse spleen. AD-MSC-Exos were characterized and the efficacy of miR-10a delivery was evaluated. The expression levels of T-bet, GATA3, RORγt, and Foxp3 and the secreted levels of IFN-γ, IL-4, IL-17, and TGF-ß respectively specific to Th1, Th2, Th17 and Treg, were assessed by qPCR and ELISA. KEY FINDINGS: Being transferred by AD-MSC-Exo, miR-10a was effectively induced in CD4+ T cells. Upon treatment with miR-10a loaded exosomes, the expression levels of RORγt and Foxp3 were enhanced and that of T-bet was reduced. Similarly, the secreted levels of IL-17, and TGF-ß were increased and that of IFN-γ was decreased. SIGNIFICANCE: Our data indicate that miR-10a loaded exosomes, promote Th17 and Tregs response while reduce that of Th1. Promotion of both Th17 and Tregs in concert, mediated by the combined effect of miR-10a and MSC-Exo, indicate new therapeutic potentials, particularly in line with novel anti-tumor immunotherapeutic strategies.

Inhibition of miR-34a reduces cellular senescence in human adipose tissue-derived mesenchymal stem cells through the activation of SIRT1.

AIMS: Human adipose derived mesenchymal stem cells (hAD-MSCs) as the most promising target for cell therapy and regenerative medicine, face senescence as a major drawback resulting in their limited proliferation and differentiation potentials. To evaluate the efficacy of miR-34a silencing as an anti-senescence strategy in hAD-MSCs, in this study common hallmarks of senescence were assessed after transient inhibition of miR-34a in hAD-MSCs. MATERIALS AND METHODS: The expression levels of miR-34a in hAD-MSCs at different passages were evaluated by real-time quantitative PCR. hAD-MSCs at passage 2 and passage 7 were transfected with miR-34a inhibitor. Doubling time assay, colony forming assay, and cell cycle analysis were performed to evaluate cell proliferation rate. The activity of senescence associated ß-galactosidase (SA-ß-gal) was assessed by histochemical staining. Moreover, the senescence associated molecular alterations including that of pro-senescence (P53, P21 and P16) and anti-senescence (SIRT1, HTERT and CD44) genes were examined by quantitative RT-PCR and western blot assays. To evaluate the differentiation potentials of MSCs, following adipogenic and osteogenic induction, the expression levels of lineage specific markers were analyzed by qPCR. KEY FINDINGS: Our results showed that inhibition of miR-34a enhances the proliferation, promotes the adipogenic and osteogenic differentiation potency, reduces the senescence associated-ß gal activity, and reverses the senescence associated molecular alterations in hAD-MSCs. SIGNIFICANCE: In this study, we showed that inhibition of miR-34a reduces the cellular senescence through the activation of SIRT1. Our findings support the silencing of miR-34a as an anti-senescence approach to improve the therapeutic potentials of hAD-MSCs.

A novel natural antisense transcript at human SOX9 locus is down-regulated in cancer and stem cells.

OBJECTIVE: SOX9 is a key transcription factor with important roles in regulating proliferation and differentiation of various cell types. Dysregulation of SOX9 expression has been involved with pathogenesis of different developmental, degenerative, and neoplastic disorders. Natural antisense transcripts (NATs) are long non-coding RNAs with increasing significance in regulation of gene expression. However, the presence of a NAT at SOX9 locus has been so far unclear. RESULT: We detected a natural antisense transcript at SOX9 locus (SOX9-NAT) through strand-specific RT-PCR. In contrast to SOX9 sense RNA (mRNA), SOX9-NAT was down-regulated in cancer tissues and cell lines compared with their normal counterparts. In addition, reciprocal to SOX9 mRNA, SOX9-NAT was also down-regulated in human embryonic stem cells in comparison with human fibroblasts in vitro. CONCLUSION: The negative correlation between SOX9 mRNA and SOX9-NAT was confirmed by analyzing qPCR data, as well as RNA-Seq datasets of several human cancers. Our data suggest a functional role for SOX9-NAT in the regulation of SOX9 mRNA as a potential target in cancer treatment and regenerative medicine.

Transient induction of Cdk9 in the early stage of differentiation is critical for myogenesis.

Cdk9 is a serine-threonine protein kinase that has been recognized as a regulator of cardiac differentiation. Recently, we have reported that transient induction of Cdk9 using noncoding RNA targeting Cdk9 sequences results in efficient cardiac differentiation. Concerning Cdk9 regulatory roles, here, we proposed whether constant overexpression of Cdk9 might influence the differentiation of myoblast C2C12 cells into myotubes. We overexpressed Cdk9 in mouse myoblast C2C12 cells to investigate its regulatory roles on myogenic differentiation. Upon Cdk9 overexpression, the expression level of myogenic regulatory factors was determined. Moreover, the expression profile of three important myomiRs consist of miR 1, 133 and 206 was examined during the differentiation process. Although Cdk9 expression is necessary for inducing differentiation in the early stage of myogenesis, continuous Cdk9 expression inhibits differentiation by modulating myomiRs and myogenic gene expression. Our results indicate that the transient induction of Cdk9 in the early stage of differentiation is critical for myogenesis.

Rn7SK small nuclear RNA is involved in cellular senescence.

Rn7SK is a conserved small nuclear noncoding RNA which its function in aging has not been studied. Recently, we have demonstrated that Rn7SK overexpression reduces cell viability and is significantly downregulated in stem cells, human tumor tissues, and cell lines. In this study, we analyzed the role of Rn7SK on senescence in adipose tissue-derived mesenchymal stem cells (AD-MSCs). For this purpose, Rn7SK expression was downregulated and upregulated via transfection and transduction, respectively, in AD-MSCs and subsequently, various distinct characteristics of senescence including cell viability, proliferation, colony formation, senescence-associated ß galactosidase activity, and differentiation potency was analyzed. Our results demonstrated the transient knockdown of Rn7SK in MSCs leads to delayed senescence, while its overexpressions shows opposite effects. When osteogenic differentiation was started, however, they exhibited a greater differentiation potential than the original MSCs, suggesting a potential tool for stem cell-based regenerative medicine.

Induced pluripotent stem cells as a new getaway for bone tissue engineering: A systematic review.

OBJECTIVES: Mesenchymal stem cells (MSCs) are frequently used for bone regeneration, however, they are limited in quantity. Moreover, their proliferation and differentiation capabilities reduce during cell culture expansion. Potential application of induced pluripotent stem cells (iPSCs) has been reported as a promising alternative source for bone regeneration. This study aimed to systematically review the available literature on osteogenic potential of iPSCs and to discuss methods applied to enhance their osteogenic potential. METHODS AND MATERIALS: A thorough search of MEDLINE database was performed from January 2006 to September 2016, limited to English-language articles. All in vitro and in vivo studies on application of iPSCs in bone regeneration were included. RESULTS: The current review is organized according to the PRISMA statement. Studies were categorized according to three different approaches used for osteo-induction of iPSCs. Data are summarized and reported according to the following variables: types of study, cell sources used for iPSC generation, applied reprogramming methods, applied osteo-induction methods and treatment groups. CONCLUSION: According to the articles reviewed, osteo-induced iPSCs revealed osteogenic capability equal to or superior than MSCs; cell sources do not significantly affect osteogenic potential of iPSCs; addition of resveratrol to the osteogenic medium (OM) and irradiatiation after osteogenic induction reduce teratoma formation in animal models; transfection with lentiviral bone morphogenetic protein 2 results in higher mineralization compared to osteo-induction in OM; addition of TGF-ß, IGF-1 and FGF-ß to OM increases osteogenic capability of iPSCs.