Oxidative stress is caused by an imbalance in the redox status of the body. In such a state, increase of free radicals in the body can lead to tissue damage. One of the most important species of free radicals is reactive oxygen species (ROS) produced by various metabolic pathways, including aerobic metabolism in the mitochondrial respiratory chain. It plays a critical role in the initiation and progression of various types of cancers. ROS affects different signaling pathways, including growth factors and mitogenic pathways, and controls many cellular processes, including cell proliferation, and thus stimulates the uncontrolled growth of cells which encourages the development of tumors and begins the process of carcinogenesis. Increased oxidative stress caused by reactive species can reduce the body's antioxidant defense against angiogenesis and metastasis in cancer cells. These processes are main factors in the development of cancer. Bimolecular reactions cause free radicals in which create such compounds as malondialdehyde (MDA) and hydroxyguanosine. These substances can be used as indicators of cancer. In this review, free radicals as oxidizing agents, antioxidants as the immune system, and the role of oxidative stress in cancer, particularly breast cancer, have been investigated in the hope that better identification of the factors involved in the occurrence and spread of cancer will improve the identification of treatment goals.
Parkinson's disease (PD) is considered as a high prevalence neurodegenerative disorders worldwide. Pathologically, the demise of dopamine-producing cells, in large part due to an abnormal accumulation of the α-synuclein in the substantia nigra, is one of the main causes of the disease. Up until now, many de novo investigations have been conducted to disclose the mechanisms underlying in PD. Among them, impacts of non-coding RNAs (ncRNAs) on the pathogenesis and/or progression of PD need to be highlighted. microRNAs (miRNAs) and long ncRNAs (lncRNAs) are more noteworthy in this context. miRNAs are small ncRNAs (with 18-25 nucleotide in length) that control the expression of multiple genes at post-transcriptional level, while lncRNAs have longer size (over 200 nucleotides) and are involved in some key biological processes through various mechanisms. Involvement of miRNAs has been well documented in the development of PD, particularly gene expression. Hence, in this current review, we will discuss the impacts of miRNAs in regulation of the expression of PD-related genes and the role of lncRNAs in the pathogenesis of PD.
The science of gene therapy has experienced a controversial history. At first, the initial concept that various disorders become curable by gene transferring was very exciting and challengeable. However, the problems and difficulties related to emerging techniques and unwanted side effects seen in some patients who have undergone gene therapy make some questions against the safety of novel molecular medicine approach. In line with this statement, discovery and developing a good bio-vector possessing low toxicity and high efficiency rate are the most important issues in gene therapy field. Introducing exosomes as vectors for gene delivery gives us a new opportunity in gene-based therapy. Exosomes, ranging from 30 to 120 nm in diameter, have unique lipid and protein composition. These nanostructures participate in cell-to-cell cross-talk, regulation of immune system, and the transport of genetic material. Besides the inherent potency of exosomes in gene therapy, a better understanding of their biology, characteristics, production, targeting, and cargo loading still need to be elucidated. In the current review, we exclusively focused on the various facets of exosomes and their importance as a bio-shuttle in gene therapy.
The current study aimed to address the impact of serum from type 2 diabetes patients on the angiogenic properties of human bone marrow mesenchymal stem cells and its relationship to autophagy signaling. Human primary stem cells were enriched and incubated with serum from diabetic and normal subjects for 7 days. Compared to data from the control group, diabetic serum was found to induce a higher cellular death rate (P < 0.001) and apoptotic changes (P < 0.01). We also showed that diabetic condition significantly abolished angiogenesis tube formation on Matrigel substrate, decreased cell chemotaxis (P < 0.01) in response to SDF-1α, and inhibited endothelial differentiation rate (P < 0.0001). Western blotting showed autophagic status by high levels of P62 (P < 0.0001), beclin-1 (P < 0.0001), and increase in LC3II/I ratio (P < 0.001). In vivo Matrigel plug assay revealed that supernatant conditioned media prepared from cells exposed to diabetic serum caused a marked reduction in the recruitment of VE-cadherin- (P < 0.01) and α-SMA-positive (P < 0.0001) cells 7 days after subcutaneous injection. PCR expression array analysis confirmed the overexpression of autophagy and apoptosis genes in cultured cells in response to a diabetic condition (P < 0.05). Using bioinformatic analysis, we noted a crosstalk network between DM2, angiogenesis, and autophagy signaling. DM2 could potently modulate angiogenesis by the interaction of IL-1β with downstream insulin receptor and upstream androgen receptor. Corroborating to data, diabetic serum led to abnormal regulation of P62 during the angiogenic response. These data demonstrate that diabetic serum decreased human mesenchymal stem cell angiogenic properties directly on angiogenesis pathways or by the induction of autophagy signaling. J. Cell. Biochem. 118: 1518-1530, 2017. © 2016 Wiley Periodicals, Inc.
Up to present, many advantages have been achieved in the field of cell-based therapies by applying sophisticated methodologies and delivery approaches. Microcapsules are capable to provide safe microenvironment for cells during transplantation in a simulated physiological 3D milieu. Here, we aimed to investigate the effect of alginate-gelatin encapsulation on angiogenic behavior of human endothelial cells over a period of 5 days. Human umbilical vein endothelial cells were encapsulated by alginate-gelatin substrate and incubated for 5 days. MTT and autophagy PCR array analysis were used to monitor cell survival rate. For in vitro angiogenesis analysis, cell distribution of Tie-1, Tie-2, VEGFR-1, and VEGFR-2 were detected by ELISA. In addition to in vitro tubulogenesis assay, we monitored the expression of VE-cadherin by Western blotting. The migration capacity of encapsulated HUVECs was studied by measuring MMP-2 and MMP-9 via gelatin zymography. The in vivo angiogenic potential of encapsulated HUVECs was analyzed in immune-compromised mouse implant model during 7 days post-transplantation. We demonstrated that encapsulation promoted HUVECs cell survival and proliferation. Compared to control, no significant differences were observed in autophagic status of encapsulated cells (p > 0.05). The level of Tie-1, Tie-2, VEGFR-1, and VEGFR-2 were increased, but did not reach to significant levels. Encapsulation decreased MMP-2, -9 activity and increased the VE-cadherin level in enclosed cells (p < 0.05). Moreover, an enhanced in vivo angiogenic response of encapsulated HUVECs was evident as compared to non-capsulated cells (p < 0.05). These observations suggest that alginate-gelatin encapsulation can induce angiogenic response in in vivo and in vitro conditions.
The distinct role of low-level laser irradiation (LLLI) on endothelial exosome biogenesis remains unclear. We hypothesize that laser irradiation of high dose in human endothelial cells (ECs) contributes to the modulation of exosome biogenesis via Wnt signaling pathway. When human ECs were treated with LLLI at a power density of 80 J/cm, the survival rate reduced. The potential of irradiated cells to release exosomes was increased significantly by expressing genes CD63, Alix, Rab27a, and b. This occurrence coincided with an enhanced acetylcholine esterase activity, pseudopodia formation, and reduced zeta potential value 24 h post-irradiation. Western blotting showed the induction of LC3 and reduced level of P62, confirming autophagy response. Flow cytometry and electron microscopy analyses revealed the health status of the mitochondrial function indicated by normal ΔΨ activity without any changes in the transcription level of PINK1 and Optineurin. When cells exposed to high power laser irradiation, p-Akt/Akt ratio and in vitro tubulogenesis capacity were blunted. PCR array and bioinformatics analyses showed the induction of transcription factors promoting Wnt signaling pathways and GTPase activity. Thus, LLLI at high power intensity increased exosome biogenesis by the induction of autophagy and Wnt signaling. LLLI at high power intensity increases exosome biogenesis by engaging the transcription factors related to Wnt signaling and autophagy stimulate.
Background: Breast cancer is caused by breast tissue malignant cells and it has become one of the main medical concerns with a socio-economic significance especially for women. Among the multiple factors involved in the initiation, progression, and invasion of breast cancer, oxidative stress plays an important role. Antioxidant status, lipid peroxidation, and oxidative stress in newly diagnosed breast cancer patients were determined to find a defined pattern of oxidative stress in these patients. Methods: The malondialdehyde (MDA) levels (as an indicator of lipid peroxidation), glutathione peroxidase (GPX), and superoxide dismutase (SOD) activities of newly diagnosed breast cancer patients (n=38) and controls (n=38) were assessed using blood samples. Results: MDA level and SOD activity were significantly higher in the breast cancer patients compared to the healthy subjects group (p<0.05). Compared to the healthy group, GPX activity decreased significantly in patients group (p<0.05). Conclusions: High lipid peroxidation is an important risk factor for breast cancer and the increased levels of superoxide anion in breast cancer cells may be a reason for the induction of SOD activity. Nevertheless, oxidative stress is an important factor in development and progression of breast cancer. Further studies on it can lead to a more helpful approach to management of breast cancer.
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