CDK9 Regulates Apoptosis of Myoblast Cells by Modulation of microRNA-1 Expression

Increased Expression of MiRNA-1 Contributes to Hypobaric Hypoxia-Induced Skeletal Muscle Loss

The present study aims to analyze the role of microRNA-1 in the regulation of skeletal muscle loss under hypobaric hypoxia (HH). Male Sprague Dawley rats (n = 10) weighing 230-250 g are divided into two groups, control and HH exposure for 7 days at 25 000 ft. After the hypoxia exposure, the animals are sacrificed and hindlimb skeletal muscles are excised for further analysis. Studies found the potential role of miR-1 (myomiR) as a biomarker under different atrophic conditions. Prolonged exposure to HH leads to enhanced expression of miR-1 in skeletal muscle as compared to unexposed controls. The Bioinformatics approach is used to identify the validated targets and the biological processes of miR-1. The target prediction tools identify PAX3 and HSP70 as major targets for miR-1. Exposure to HH significantly reduces PAX3 and HSP70 expression during 7 days of HH exposure, which further enhances the activity of FOXO3, MSTN, and ATROGIN known for the progression of skeletal muscle atrophy in relation to control rats. This study indicates the increased expressions of miR-1 and reduced expression of PAX3 and HSP70 lead to impaired myogenesis in skeletal muscle under HH. Further, enhanced expression of muscle degradation genes such as FOXO3, MSTN, and ATROGIN under HH exposure causes skeletal muscle protein loss.

7SK small nuclear RNA (Rn7SK) induces apoptosis through intrinsic and extrinsic pathways in human embryonic kidney cell line

BACKGROUND

Rn7SK, a highly conserved small nuclear non-coding RNA, controls Polymerase II transcription machinery by activating of the Positive Transcriptional Elongation Factor b (P-TEFb). Apart from its role in transcriptional regulation, the potential functions of Rn7SK in cell apoptosis are poorly understood. In a previous study, we demonstrated that overexpression of 7SK induces apoptosis in HEK cells. However, it remains unclear whether 7SK-mediated apoptosis induction is exerted through the intrinsic or extrinsic pathways.

METHODS AND RESULTS

Rn7SK was overexpressed in HEK 293T cell line using Lipofectamine 2000 reagent to investigate its potential apoptotic functions. The overexpression of Rn7SK resulted in reduced cell viability through the induction of apoptosis, as evidenced by MTT assay and Annexin V/PI staining. Concurrently, alterations in the expression levels of key apoptosis-related genes were observed, as determined by quantitative RT-PCR. Furthermore, Rn7SK overexpression led to a decrease in cell proliferation, as assessed by colony formation assay and growth curve analysis. This reduction was associated with downregulated expression of key proliferative-related genes. Additionally, the migration and invasion capabilities of cells were significantly inhibited upon upregulation of Rn7SK, as demonstrated by transwell assays.

CONCLUSIONS

This study suggests the apoptotic role of 7SK through both intrinsic and extrinsic pathways, necessitating further investigation into its underlying mechanisms.

MicroRNA-1 targets ribosomal protein genes to regulate the growth, development and reproduction of Schistosoma japonicum

Eggs laid by mature female schistosomes are primarily responsible for the pathogenesis of schistosomiasis and critical for transmission. Consequently, elucidating the mechanism of sexual maturation as well as egg production may lead to new strategies for the control of schistosomiasis. MicroRNAs (miRNAs) are involved in multiple biological processes including reproduction in many organisms, yet their roles have not been well characterized in schistosomes. Here, we investigated microRNA-1 (miR-1), which was downregulated gradually in both male and female Schistosoma japonicum after they reached sexually maturity. The expression of miR-1, as shown with quantitative reverse transcription PCR (qRT-PCR), was lower in the reproductive organs of adult females compared with the somatic tissues. Overexpression of miR-1 in adult worms destroyed the morphological architecture of reproductive organs and reduced the subsequent oviposition, which may be due to the activation of apoptosis pathways. Through in silico analysis, 34 potential target genes of miR-1 were identified, including five ribosomal protein genes, called rp-s13, rp-l7ae, rp-l14, rp-l11 and rp-s24e. In vitro dual-luciferase reporter gene assays and miRNA overexpression experiments further validated that these ribosomal protein genes were directly regulated by miR-1. In contrast to the gene expression of miR-1, qRT-PCR and in situ hybridization experiments demonstrated these ribosomal protein genes were enriched in the sexual organs of adult females. Using RNA interference to silence the ribosomal protein genes in different developmental stages in a mouse model system, we demonstrated that these miR-1 target genes not only participated in the reproductive development of S. japonicum, but also were required for the growth and survival of the parasite in the early developmental stages. Taken together, our data suggested that miR-1 may affect the growth, reproduction and oviposition of S. japonicum by targeting the ribosomal protein genes, which provides insights for exploration of new anti-schistosome strategies.

A snapshot of miRNAs in oral squamous cell carcinoma: Difference between cancer cells and corresponding normal cells

Oral squamous cell carcinoma (OSCC) constitutes the most aggressive tumors of the oral cavity and is one of the leading causes of cancer mortality worldwide. Although recent clinical treatment strategies have improved the survival rate, the outcome of OSCC patients still remains dismal because of the lack of efficient diagnostic and treatment tools. As one of the main actors of OSCC scenario, microRNAs (miRNAs) are involved in triggering, progression and metastasis through the regulation of various cancer-related signaling pathways. Identification followed by precise study of the biology and mechanism of action of miRNAs will greatly help to provide valuable insights regarding OSCC development and can be considered as an anti-OSCC target. In the current review, we have provided a focused summary of the latest published papers on the role of miRNAs in apoptosis, cell cycle, proliferation, EMT and metastasis of OSCC as well as the role of long noncoding RNAs in the modulation of miRNAs in OSCC.

Exosome-based strategies for diagnosis and therapy of glioma cancer

Glioblastoma belongs to the most aggressive type of cancer with a low survival rate that is characterized by the ability in forming a highly immunosuppressive tumor microenvironment. Intercellular communication are created via exosomes in the tumor microenvironment through the transport of various biomolecules. They are primarily involved in tumor growth, differentiation, metastasis, and chemotherapy or radiation resistance. Recently several studies have highlighted the critical role of tumor-derived exosomes against immune cells. According to the structural and functional properties, exosomes could be essential instruments to gain a better molecular mechanism for tumor understanding. Additionally, they are qualified as diagnostic/prognostic markers and therapeutic tools for specific targeting of invasive tumor cells such as glioblastomas. Due to the strong dependency of exosome features on the original cells and their developmental status, it is essential to review their critical modulating molecules, clinical relevance to glioma, and associated signaling pathways. This review is a non-clinical study, as the possible role of exosomes and exosomal microRNAs in glioma cancer are reported. In addition, their content to overcome cancer resistance and their potential as diagnostic biomarkers are analyzed.

Modified gelatin/iron- based metal-organic framework nanocomposite hydrogel as wound dressing: Synthesis, antibacterial activity, and Camellia sinensis release

A new kind of Camellia sinensis-loaded nanocomposite hydrogel based on modified gelatin/iron-metal-organic framework was developed as an antibacterial wound dressing. Gelatin as a biocompatible natural polymer was modified with methacrylate anhydride to produce gelatin methacrylate. Thereafter, acrylic acid and acrylamide were grafted on gelatin methacrylate during an aqueous polymerization process. To enhance the porosity, mechanical strength, and drug loading capability of the hydrogel and reduce its toxicity, iron- based metal-organic framework was incorporated within the hydrogel. To add more functionality to the final wound dressing, Camellia sinensis, an antibacterial herbal drug was loaded on the hydrogel. The structural and chemical properties of prepared nanocomposite hydrogel were investigated by FTIR, XRD, SEM, and TGA techniques. The incorporation of iron-based metal-organic framework within the hydrogel matrix led to an increase in its water absorption value from 400.10 to 547.96 (g/g). The release study of Camellia sinensis (CS) extract from the prepared nanocomposite hydrogel exhibited a sustained release manner. The antibacterial test revealed the nanocomposite hydrogel contain extract has an effective antibacterial function against "Bacillus serous", "Staphylococcus aureus", "Streptococcus mutans"," Escherichia coli", "Klebsiella pneumoniae", and "Pseudomonas aeruginosa" bacteria. Therefore, the synthesized nanocomposite is a good candidate as an antibacterial hydrogel wound dressing. .

Targeting cyclin-dependent kinase 9 in cancer therapy

Cyclin-dependent kinase (CDK) 9 associates mainly with cyclin T1 and forms the positive transcription elongation factor b (p-TEFb) complex responsible for transcriptional regulation. It has been shown that CDK9 modulates the expression and activity of oncogenes, such as MYC and murine double minute 4 (MDM4), and it also plays an important role in development and/or maintenance of the malignant cell phenotype. Malfunction of CDK9 is frequently observed in numerous cancers. Recent studies have highlighted the function of CDK9 through a variety of mechanisms in cancers, including the formation of new complexes and epigenetic alterations. Due to the importance of CDK9 activation in cancer cells, CDK9 inhibitors have emerged as promising candidates for cancer therapy. Natural product-derived and chemically synthesized CDK9 inhibitors are being examined in preclinical and clinical research. In this review, we summarize the current knowledge on the role of CDK9 in transcriptional regulation, epigenetic regulation, and different cellular factor interactions, focusing on new advances. We show the importance of CDK9 in mediating tumorigenesis and tumor progression. Then, we provide an overview of some CDK9 inhibitors supported by multiple oncologic preclinical and clinical investigations. Finally, we discuss the perspective and challenge of CDK9 modulation in cancer.

Mesenchymal Stem Cells cause Telomere Length Reduction of Molt-4 Cells via Caspase-3, BAD and P53 Apoptotic Pathway

Mesenchymal stem cells (MSCs) as undifferentiated cells are specially considered in cell-based cancer therapy due to unique features such as multi-potency, pluripotency, and self-renewal. A multitude of cytokines secreted from MSCs are known to give such multifunctional attributes, but details of their role are yet to be unknown. In the present study, MSCs were cultured, characterized and co-cultured with Molt-4 cells as acute lymphoblastic leukemia cell line in a trans-well plate. Then, cultured Molt-4 alone and Molt-4 co-cultured with MSCs (10:1) were collected on day 7 and subjected to real time-PCR and Western blotting for gene and protein expression assessment, respectively. Ki-67/caspase-3 as well as telomere length were investigated by flow cytometry and real time-PCR, respectively. The results showed that MSCs caused significant decrease in telomere length as well as hTERT gene expression of Molt-4 cells. Also, gene and protein expression of BAD and P53 were significantly increased. Furthermore, the flow cytometry analysis indicated the decrease and increase of the Ki-67 and caspaspase-3 expression, respectively. It was concluded that MSCs co-cultured with Molt-4 cells could be involved in the promotion of Molt-4 cell apoptosis via caspase-3, BAD, and P53 expression. In addition, the decrease of telomere length is another effect of MSCs on Molt-4 leukemic cells.

Hepatoprotective effects of sericin on aging-induced liver damage in mice

Aging is a physiological process in which there is a progressive decline of function in multiple organs such as the liver. The development of natural therapies, such as sericin, for delaying age-associated diseases is of major interest in this regard. Twenty-seven mice were divided into three groups of nine, including young control group (8 weeks, received normal saline), aged control group (24 months, received normal saline), and sericin-treated aged mice (24 months, received sericin at dose 100 mg/kg/day) via oral administration for 14 days. The liver enzymes in serum and oxidative stress markers in liver tissue were evaluated using spectrophotometric/ELISA methods. Apoptotic proteins, pro-inflammatory cytokines, COX2, JNK, and P-38 levels were assessed by western blot analysis. β-galactosidase expression was determined by a qRT-PCR method. The findings showed that 100 mg/kg of sericin reduced liver enzymes in aged mice. Antioxidant capacity in treated aged mice showed an improvement in all indexes in the liver tissue. Also, sericin administration declined pro-inflammatory markers to varying degrees in aged-treated mice. Sericin also increased the expression level of Bcl-2 and decreased the expression level of Bax and cleaved caspase-3.In addition, treatment with sericin suppressed protein expression of p-JNK and p-JNK/JNK. Collectively, these findings would infer that sericin administration may have a hepatoprotective effect in aging-induced liver damage in mice.

The Impact of EGCG and RG108 on SOCS1 Promoter DNA Methylation and Expression in U937 Leukemia Cells

BACKGROUND

The available evidence has increasingly demonstrated that a combination of genetic and epigenetic factors, such as DNA methylation, could be considered as causing leukemia. Epigenetic changes and methylation of the suppressor of the cytokine signaling 1 promoter (SOCS1) CpG region silence SOCS1 expression in cancer. In the current study, we evaluated the impact of epigallocatechin gallate (EGCG) and RG108 on SOCS1 promoter methylation and expression in U937 cells.

METHODS

In the current study, U937 leukemic cells were treated with EGCG and RG108 for 12, 24, 48, and 72 h and SOCS1 promoter methylation and its expression were measured by methylation-specific PCR (MSP) and quantitative real-time PCR, respectively.

RESULTS

The outcomes indicated that the SOCS1 promoter is methylated in U937 cells, and treatment of these cells with either EGCG or RG108 reduced its methylation. Moreover, we observed that SOCS1 expression was significantly upregulated in a time-dependent manner by both EGCG and RG108 in U937 cells compared with control cells. In the RG108-treated group at 12, 24, 48, and 72 h, SOCS1 expression was upregulated by 1, 4.2, 16.6, and 32.6 -fold respectively, and in the EGCG-treated group, by 0.5, 3.2, 10.8, and 22.3 -fold, respectively.

CONCLUSION

Treatment with either EGCG or RG108 reduced SOCS1 promoter methylation and increased SOCS1 expression in U937 cells in a time-dependent manner, which may play a role in leukemia therapy.

Silver nanoparticles induce the cardiomyogenic differentiation of bone marrow derived mesenchymal stem cells via telomere length extension

Finding new strategies for the treatment of heart failures using stem cells has attracted a lot of attention. Meanwhile, nanotechnology-based approaches to regenerative medicine hypothesize a possible combination of stem cells and nanotechnology in the treatment of diseases. This study aims to investigate the in vitro effect of silver nanoparticles (Ag-NPs) on the cardiomyogenic differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs) through detection of cardiac markers. For this purpose, MSCs were isolated from bone marrow resident and differentiated to the cardiac cells using a dedicated medium with Ag-NPs. Also, the cardiomyogenic differentiation of BM-MSCs was confirmed using immunocytochemistry. Then, real-time PCR and western blotting assay were used for measuring absolute telomere length (TL) measurement, and gene and protein assessment of the cells, respectively. It was found that 2.5 µg/mL Ag-NPs caused elongation of the telomeres and altered VEGF, C-TnI, VWF, SMA, GATA-4, TERT, and cyclin D protein and gene expression in the cardiomyogenically differentiated BM-MSCs. Also, there was a significant increase in the protein and gene expression of Wnt3 and β-catenin as main components of pathways. We concluded that Ag-NPs could change the in vitro expression of cardiac markers of BM-MSCs via the Wnt3/β-catenin signaling pathway.

Recent Advances on Immune Targeted Therapy of Colorectal Cancer Using bi-Specific Antibodies and Therapeutic Vaccines

Colorectal cancer (CRC) is a universal heterogeneous disease that is characterized by genetic and epigenetic alterations. Immunotherapy using monoclonal antibodies (mAb) and cancer vaccines are substitute strategies for CRC treatment. When cancer immunotherapy is combined with chemotherapy, surgery, and radiotherapy, the CRC treatment would become excessively efficient. One of the compelling immunotherapy approaches to increase the efficiency of CRC therapy is the deployment of therapeutic mAbs, nanobodies, bi-specific antibodies and cancer vaccines, which improve clinical outcomes in patients. Also, among the possible therapeutic approaches for CRC patients, gene vaccines in combination with antibodies are recently introduced as a new perspective. Here, we aimed to present the current progress in CRC immunotherapy, especially using Bi-specific antibodies and dendritic cells mRNA vaccines. For this aim, all data were extracted from Google Scholar, PubMed, Scopus, and Elsevier, using keywords cancer vaccines; CRC immunotherapy and CRC mRNA vaccines. About 97 articles were selected and investigated completely based on the latest developments and novelties on bi-specific antibodies, mRNA vaccines, nanobodies, and MGD007.

Recent Advances in Therapeutic Peptides for Breast Cancer Treatment

Breast cancer is a heterogeneous malignancy and is the second leading cause of mortality among women around the world. Increasing the resistance to anti-cancer drugs in breast cancer cells persuades researchers to search the novel therapeutic approaches for the treatment of this malignancy. Among the novel methods, therapeutic peptides that target and disrupt tumor cells have been of great interest. Therapeutic peptides are short amino acid monomer chains with high specificity to bind and modulate a protein interaction of interest. Several advantages of peptides, such as specific binding on tumor cells surface, low molecular weight, and low toxicity on normal cells, make the peptides appealing therapeutic agents against solid tumors, particularly breast cancer. Also, the National Institutes of Health (NIH) describes therapeutic peptides as a suitable candidate for the treatment of drug-resistant breast cancer. In this review, we attempt to review the different therapeutic peptides against breast cancer cells that can be used in the treatment and diagnosis of the malignancy. Meanwhile, we presented an overview of peptide vaccines that have been developed for the treatment of breast cancer.

Small Activating RNAs: Towards the Development of New Therapeutic Agents and Clinical Treatments

Small double-strand RNA (dsRNA) molecules can activate endogenous genes via an RNA-based promoter targeting mechanism. RNA activation (RNAa) is an evolutionarily conserved mechanism present in diverse eukaryotic organisms ranging from nematodes to humans. Small activating RNAs (saRNAs) involved in RNAa have been successfully used to activate gene expression in cultured cells, and thereby this emergent technique might allow us to develop various biotechnological applications, without the need to synthesize hazardous construct systems harboring exogenous DNA sequences. Accordingly, this thematic issue aims to provide insights into how RNAa cellular machinery can be harnessed to activate gene expression leading to a more effective clinical treatment of various diseases.

miR-1: A comprehensive review of its role in normal development and diverse disorders

MicroRNA-1 (miR-1) is a conserved miRNA with high expression in the muscle tissues. In humans, two discrete genes, MIRN1-1 and MIRN1-2 residing on a genomic region on 18q11.2 produce a single mature miRNA which has 21 nucleotides. miR-1 has a regulatory role on a number of genes including heat shock protein 60 (HSP60), Kruppel-like factor 4 (KLF4) and Heart And Neural Crest Derivatives Expressed 2 (HAND2). miR-1 has critical roles in the physiological processes in the smooth and skeletal muscles as well as other tissues, thus being involved in the pathogenesis of a wide range of disorders. Moreover, dysregulation of miR-1 has been noted in diverse types of cancers including gastric, colorectal, breast, prostate and lung cancer. In the current review, we provide the summary of the data regarding the role of this miRNA in the normal development and the pathogenic processes.

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-β 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-β 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 β-galactosidase (SA-β-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-β 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.

Critical roles of long noncoding RNAs in breast cancer

Breast cancer is a major clinical challenge that affects a wide range of the female population and heavily burdens the health system. In the past few decades, attempts have been made to understand the etiology of breast cancer, possible environmental risk factors, and the genetic predispositions, pathogenesis, and molecular aberrations involved in the process. Studies have shown that breast cancer is a heterogeneous entity; each subtype has its specific set of aberrations in different cell signaling pathways, such as Notch, Wnt/β-catenin, transforming growth factor-β, and mitogen-activated protein kinase pathways. One novel group of molecules that have been shown to be inducted in the regulation of multiple cell signaling pathways is the long noncoding RNAs (lncRNAs). These molecules have important implications in the regulation of multiple signaling pathways by interacting with various genes, affecting the transcription process, and finally, playing roles in posttranslational control of these genes. There is growing evidence that lncRNAs are involved in the process of breast cancer formation by effecting the aforementioned signaling pathways, and that this involvement can have significant diagnostic and prognostic values in clinical contexts. The present review aims to elicit the significance of lncRNAs in the regulation of cell signaling pathways, and the resulting changes in cell survival, proliferation, and invasion, which are the hallmarks of breast cancer.

MicroRNAs in breast cancer: Roles, functions, and mechanism of actions

Breast cancer is one of the most lethal malignancies in women in the world. Various factors are involved in the development and promotion of the malignancy; most of them involve changes in the expression of certain genes, such as microRNAs (miRNAs). MiRNAs can regulate signaling pathways negatively or positively, thereby affecting tumorigenesis and various aspects of cancer progression, particularly breast cancer. Besides, accumulating data demonstrated that miRNAs are a novel tool for prognosis and diagnosis of breast cancer patients. Herein, we will review the roles of these RNA molecules in several important signaling pathways, such as transforming growth factor, Wnt, Notch, nuclear factor-κ B, phosphoinositide-3-kinase/Akt, and extracellular-signal-regulated kinase/mitogen activated protein kinase signaling pathways in breast cancer.

Targeting miRNAs by polyphenols: Novel therapeutic strategy for aging

Regarding the importance of genetic and epigenetic factors in regulation of aging process, different expression pattern of non-coding RNAs in aging could be investigated. Accordingly, micro RNAs (miRNAs) with a wide range of physiological functions as well as a significant footprint in many diseases have been demonstrated to be down or upregulated during the aging process. Therefore, age-associated microRNAs and their targets have potentially detected the accelerated aging and predicted the risks for age-related diseases. Polyphenols as important antioxidants in human dietary observed in fruits and some beverages have beneficial effects on longevity and aging. Considering miRNAs as an interesting mediator in modulating polyphenols' biological effects, targeting miRNAs which is using polyphenols could be a novel strategy for aging.

Combination of exercise training and L-arginine reverses aging process through suppression of oxidative stress, inflammation, and apoptosis in the rat heart

Aging-induced progressive decline of molecular and metabolic factors in the myocardium is suggested to be related with heart dysfunction and cardiovascular disease. Therefore, we evaluated the effects of exercise training and L-arginine supplementation on oxidative stress, inflammation, and apoptosis in ventricle of the aging rat heart. Twenty-four 24-month-aged Wistar rats were randomly divided into four groups: the aged control, aged exercise, aged L-arginine (orally administered with 150 mg/kg for 12 weeks), and aged exercise + L-arginine groups. Six 4-month-old rats were also considered the young control. Animals with training program performed exercise on a treadmill 5 days/week for 12 weeks. After 12 weeks, protein levels of Bax, Bcl-2, pro-caspase-3/cleaved caspase-3, cytochrome C, and heat shock protein (HSP)-70 were assessed. Tissue contents of total anti-oxidant capacity, superoxide dismutase, catalase, and levels of tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 were analyzed. Histological and fibrotic changes were also evaluated. Treadmill exercise and L-arginine supplementation significantly alleviated aging-induced apoptosis with enhancing HSP-70 expression, increasing anti-oxidant enzyme activity, and suppressing inflammatory markers in the cardiac myocytes. Potent attenuation in apoptosis, inflammation, and oxidative stress was indicated in the rats with the combination of L-arginine supplementation and exercise program in comparison with each group (p < 0.05). In addition, fibrosis percentage and collagen accumulation were significantly lower in the rats with the combination treatment of L-arginine and exercise (p < 0.05). Treadmill exercise and L-arginine supplementation provided protection against age-induced increase in the myocyte loss and formation of fibrosis in the ventricle through potent suppression of oxidative stress, inflammations, and apoptosis pathways.

Downregulation of TdT Expression through Splicing Modulation by Antisense Peptide Nucleic Acid (PNA)

BACKGROUND AND OBJECTIVE

Antisense oligonucleotides are able to modulate splicing patterns and offer therapeutic intervention for cancer and other diseases. Considering TdT potential as a target in cancer therapy, the present study aimed to investigate splicing alteration of TdT pre-mRNA in Molt-4 cells using peptide nucleic acid (PNA) octaarginine and cholic acid conjugates.

METHOD

We examined 16 mer PNAs targeting 5' and 3' junctions of intron 7 and addressed their mRNA splicing modulation effects using RT-PCR analysis. We also tested corresponding 2-base mismatch PNAs to confirm the sequence specificity. In addition, protien level of TdT, apoptosis induction and cell viability rate were analysed.

RESULTS

PCR analysis showed that full match PNAs could modulate the splicing process, thereby producing a longer mRNA still including intron 7. PCR results also implied exon 7 skipping. In addition, reduced level of TdT protein in Molt-4 cells was observed. Downregulation of TdT level in PNA treated cells was accompanied by an increased rate of apoptosis and decreased the level of cell survival.

CONCLUSION

PNA-mediated splicing modulation can specifically downregulate TdT expression. TdT dowregulation results in apoptosis induction and reduced cell survival in Molt-4 cells. These observations could draw more attentions to develop PNA based strategies for TdT suppression and consequent apoptosis induction in acute lymphoblastic leukemia.

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 β 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.

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.

Layered double hydroxide nanoparticles as an appealing nanoparticle in gene/plasmid and drug delivery system in C2C12 myoblast cells

Gene and drug delivery systems need crucial update in the issue of nanocarriers. Layered double hydroxides (LDHs) are known as biocompatible inorganic lamellar nanomaterials with versatile properties. In the present study, Zn/Al-LDH nanoparticle was synthesized and characterized by FTIR, XRD, SEM, TEM and Zeta potential tests and then intercalated with valproate and methyldopa by co-precipitation and ion exchange methods. These nanocarriers were applied as high activity nanolayers-based delivery systems. On the other hand, Zn/Al-LDH + plasmid/gene (pCEP4/Cdk9) evaluated on C2C12 myoblast cells. Co-operation loading indicated high efficiency of sorting and release of drugs. Additionally, the Real-Time PCR and Western blotting results for plasmid-gene (pCEP4/Cdk9) delivery showed that Zn/Al-LDH nanoparticles can be used as an effective carrier in cellular uptake and release of genes for gene therapy. Easy and cost-effective production of Zn/Al-LDH nanoparticles proposed them as potential alternatives for the traditional routs of drug/gene delivery.