Exosome-loaded decellularized tissue: Opening a new window for regenerative medicine

Mesenchymal stem cell-derived exosomes (MSCs-EXO) have received a lot of interest recently as a potential therapeutic tool in regenerative medicine. Extracellular vesicles (EVs) known as exosomes (EXOs) are crucial for cell-cell communication throughout a variety of activities including stress response, aging, angiogenesis, and cell differentiation. Exploration of the potential use of EXOs as essential therapeutic effectors of MSCs to encourage tissue regeneration was motivated by success in the field of regenerative medicine. EXOs have been administered to target tissues using a variety of methods, including direct, intravenous, intraperitoneal injection, oral delivery, and hydrogel-based encapsulation, in various disease models. Despite the significant advances in EXO therapy, various methods are still being researched to optimize the therapeutic applications of these nanoparticles, and it is not completely clear which approach to EXO administration will have the greatest effects. Here, we will review emerging developments in the applications of EXOs loaded into decellularized tissues as therapeutic agents for use in regenerative medicine in various tissues.

Accelerated wound healing with resveratrol-loaded decellularized pericardium in mice model

One of the key objectives of regenerative medicine is the design of skin tissue engineering scaffolds to promote wound healing. These scaffolds provide a fresh viewpoint on skin injury repair by emulating body tissues in their structure. A suitable platform for cellular processes can be provided by natural scaffolds made from decellularized tissues while retaining the primary components. Resveratrol (RES), which has qualities like angiogenesis, antioxidant, antibacterial, and anti-inflammatory, is also useful in the healing of wounds. In this investigation, RES-loaded decellularized sheep pericardium scaffolds were created and tested on full-thickness wounds in a mouse model. According to the in vivo findings, the groups in which the wound was treated with decellularized pericardium (DP) had better wound healing than the control group and showed more production of angiogenic and anti-inflammatory substances. The secretion of these factors was greater in RES-loaded decellularized pericardium (DP-RES) than in the scaffold without RES, and the macroscopic and histological data supported this. Therefore, the use of decellularization scaffolds with substances like RES for the regeneration of skin wounds can be further researched and evaluated in the preclinical stages.

Prospects of plant-derived exosome-like nanocarriers in oncology and tissue engineering

Almost all cell types, either in vivo or in vitro, create extracellular vesicles (EVs). Among them are exosomes (EXOs), i.e., tiny nanovesicles containing a lipid bilayer, proteins, and RNAs that are actively involved in cellular communication, indicating that they may be exploited as both diagnostics and therapeutics for conditions like cancer. These nanoparticles can also be used as nanocarriers in many types of research to carry agents such as drugs. Plant-derived exosome-like nanoparticles (PENs) are currently under investigation as a substitute for EXOs formed from mammalian cells, allowing researchers to get beyond the technical constraints of mammalian vesicles. Because of their physiological, chemical, and biological properties, PENs have a lot of promise for use as nanocarriers in drug delivery systems that can deliver various dosages, especially when it comes to large-scale repeatability. The present study has looked at the origins and isolation techniques of PENs, their anticancer properties, their usage as nanocarriers in the treatment of different illnesses, and their antioxidant properties. These nanoparticles can aid in the achievement of therapeutic objectives, as they have benign, non-immunogenic side effects and can pass biological barriers. Time-consuming and perhaps damaging PEN separation techniques is used. For the current PEN separation techniques to be used in commercial and therapeutic settings, they must be altered. In this regard, the concurrent application of biological sciences can be beneficial for improving PEN separation techniques. PENs' innate metabolic properties provide them a great deal of promise for application in drug delivery systems. However, there could be a risk to both the loaded medications and the intrinsic bioactive components if these particles are heavily armed with drugs. Therefore, to prevent these side effects, more studies are needed to devise sophisticated drug-loading procedures and to learn more about the physiology of PENs.

Exosome-loaded scaffolds for regenerative medicine in hard tissues

Tissue engineering can be used to repair tissue by employing bioscaffolds that provide better spatial control, porosity, and a three-dimensional (3D) environment like the human body. Optimization of injectability, biocompatibility, bioactivity, and controlled drug release are also features of such scaffolds. The 3D shape of the scaffold can control cell interaction and improve cell migration, proliferation, and differentiation. Exosomes (EXOs) are nanovesicles that can regulate osteoblast activity and proliferation using a complex composition of lipids, proteins, and nucleic acids in their vesicles. Due to their excellent biocompatibility and efficient cellular internalization, EXOs have enormous potential as desirable drug/gene delivery vectors in the field of regenerative medicine. They can cross the biological barrier with minimal immunogenicity and side effects. Scaffolds that contain EXOs have been studied extensively in both basic and preclinical settings for the regeneration and repair of both hard (bone, cartilage) and soft (skin, heart, liver, kidney) tissue. Cell motility, proliferation, phenotype, and maturation can all be controlled by EXOs. The angiogenic and anti-inflammatory properties of EXOs significantly influence tissue healing. The current study focused on the use of EXO-loaded scaffolds in hard tissue regeneration.

Mortality and disability-adjusted life years for smoking-attributed cancers from 1990 to 2019 in the north Africa and middle east countries: a systematic analysis for the global burden of disease study 2019

AIM AND BACKGROUND

Smoking is a modifiable risk factor for cancers. The aim of the study is to estimate the trend of mortality and DALYs of smoking-attributed cancers in the North Africa and Middle East (NAME) countries.

METHODS

In this study, estimates from the Global Burden of Disease 2019 (GBD-2019) study were used to report the mortality and DALYs for 16 smoking-attributed cancers. The mortality and DALYs rates from smoking-attributed cancers were evaluated by age, sex, and the 21 countries of the NAME countries from 1990 to 2019.

RESULTS

Age standardized mortality rates (ASMR) for the 29 smoking-attributed cancers in the NAME countries in 1990 and 2019 were estimated to be 24.7 (95% Uncertainty Interval: 21.5, 27.8) and 22.4 (95%UI: 19.8, 25.4) respectively, which shows a 9.2% decrease in the three decades. DALYs/100,000 for smoking-attributed cancers was, also, estimated to be 600.3 (95%UI: 521.6, 682.6) and 515.6 (95%UI: 454.9, 585.4) respectively, which indicates a 14.1% decreased in these three decades. In the last three decades, the percentage changes in DALYs/100,000 for smoking-attributed cancers in males and females were - 0.16 and - 0.03, respectively. Plus, The percentage changes in ASMR in males and females were - 12% and 8%, respectively. Furthermore, The highest ASMR and DALYs were observed in Lebanon, Turkey, and Palestine in 2019.

CONCLUSION

The mortality rates of cancers from smoking have increased substantially among females, in most countries of the NAME region, in recent years. The burden caused by smoking can be reduced through modifying lifestyle and applying strict laws on smoking by governments and policymakers.

The effect of marine algae-derived exosomes on breast cancer cells: Hypothesis on a new treatment for cancer

Breast cancer is one of the most common cancers among women worldwide. Therefore, further research in this area remains necessary. In pursuit of cancer treatment, the use of aquatic and marine resources has been considered in recent years. Marine algae create a wide variety of metabolites with different biological activities, and their anticancer properties have been reported in several studies. With particles ranging in size between 30 and 100 nm in size, exosomes are a class of cell-released extracellular vesicles that contain DNA, RNA, and proteins. Nontoxic properties and lack of an immune response are critical considerations in the medical use of exosome nanoparticles. Studies have demonstrated that exosomes are used for cancer therapy and in several drug delivery trials; however, no study so far has been done on exosomes derived from marine algae. Research has shown that three-dimensional (3D) models of cancer are advantageous for studying drug effects. This hypothesis aims to design a 3D model of breast cancer in vitro and evaluate cell growth after treatment with a marine algae-derived exosome.

Exosomes: special nano-therapeutic carrier for cancers, overview on anticancer drugs

Chemotherapy drugs are the first line of cancer treatment, but problems such as low intratumoral delivery, poor bioavailability, and off-site toxicity must be addressed. Cancer-specific drug delivery techniques could improve the therapeutic outcome in terms of patient survival. The current study investigated the loading of chemotherapy drugs loaded into exosomes for cancer treatment. Exosomes are the smallest extracellular vesicles found in body fluids and can be used to transfer information by moving biomolecules from cell to cell. This makes them useful as carriers. As the membranes of these nanoparticles are similar to cell membranes, they can be easily transported to carry different components. As most chemotherapy drugs are not easily soluble in liquid, loading them into exosomes can be a suitable solution to this problem. This cancer treatment could avert the injection of high doses of drugs and provide a more appropriate release mechanism.

An Effective Method for Decellularization of Human Foreskin: Implications for Skin Regeneration in Small Wounds

OBJECTIVE

Acellular matrices of different allogeneic or xenogeneic origins are widely used as structural scaffolds in regenerative medicine. The main goal of this research was to optimize a method for decellularization of foreskin for skin regeneration in small wounds.

MATERIALS AND METHODS

In this experimental study, the dermal layers of foreskin were divided into two sections and subjected to two different decellularization methods: the sodium dodecyl sulfate method (SDS-M), and our optimized foreskin decellularization method (OFD-M). A combination of non-ionic detergents and SDS were used to decellularize the foreskin in OFD-M. The histological, morphological, and biomechanical properties of both methods were compared. In addition, human umbilical cord mesenchymal stem cells (hucMSCs) were isolated, and the biocompatibility and recellularization of both scaffolds by hucMSC were subsequently determined.

RESULTS

We observed that OFD-M is an appropriate approach for successful removal of cellular components from the foreskin tissue, without physical disturbance to the acellular matrix. In comparison to SDS-M, this new bioscaffold possesses a fine network containing a high amount of collagen fibers and glycosaminoglycans (GAG) (P≤0.03), is biocompatible and harmless for hucMSC (viability 91.7%), and exhibits a relatively high tensile strength.

CONCLUSION

We found that the extracellular matrix (ECM) structural integrity, the main ECM components, and the mechanical properties of the foreskin are well maintained after applying the OFD-M decellularization technique, indicating that the resulting scaffold would be a suitable platform for culturing MSC for skin grafting in small wounds.

Cold Spray: Over 30 Years of Development Toward a Hot Future

Cold Spray (CS) is a deposition process, part of the thermal spray family. In this method, powder particles are accelerated at supersonic speed within a nozzle; impacts against a substrate material triggers a complex process, ultimately leading to consolidation and bonding. CS, in its modern form, has been around for approximately 30 years and has undergone through exciting and unprecedented developmental steps. In this article, we have summarized the key inventions and sub-inventions which pioneered the innovation aspect to the process that is known today, and the key breakthroughs related to the processing of materials CS is currently mastering. CS has not followed a liner path since its invention, but an evolution more similar to a hype cycle: high initial growth of expectations, followed by a decrease in interest and a renewed thrust pushed by a number of demonstrated industrial applications. The process interest is expected to continue (gently) to grow, alongside with further development of equipment and feedstock materials specific for CS processing. A number of current applications have been identified the areas that the process is likely to be the most disruptive in the medium-long term future have been laid down.

A comparative study of the effects of crab derived exosomes and doxorubicin in 2 & 3-dimensional in vivo models of breast cancer

INTRODUCTION

Using tissue engineering and modifying the tumor microenvironment, three-dimensional (3D) in vitro and in vivo cancer modeling can be performed with appropriate similarity to native. Exosomes derived from different sources have recently been used in cancer studies due to their anticancer effects. In this study, the effect of crab derived exosomes in 2 & 3-dimensional (2& 3D) in vivo models of breast cancer (BC) were investigated and compared with the doxorubicin (DOX).

METHODS

2D and 3D models of BC were induced using the chitosan/β-glycerol phosphate hydrogel (Ch/β-GP) and 1 × 10⁶ 4T1 cells in the female mice aged 6-8 weeks. 1 mg/ml exosome and 5 mg/kg DOX were injected by intratumoral (IT), intravenous (IV), and intraperitoneal (IP) methods into mice on day 9, 13, and 17 with and without hydrogel as a drug delivery system. After 21 days, the mice were sacrificed, and the tissues (lung, liver, and tumor) were removed. The weight and size of the tumor were measured. Real-time PCR assessed changes of VEGF, Bcl2, and P53 genes expression levels. Nitric oxide (NO) secretion from the cancer 3D model was evaluated by Griess assay.

RESULTS AND CONCLUSION

Based on the results, the size and weight of tumors in treated groups with exosomes and DOX were reduced significantly (P ≤ 0.001, P ≤ 0.002, P ≤ 0.02) in 2D and 3D models. Changes in VEGF, Bcl2 and P53 gene expression levels were less in the 3D model than in the 2D model. Drug delivery with hydrogel increased tumor inhibition compared to drug injection without hydrogel. Decreased NO secretion was observed in all treatment groups compared to the control group (untreated). Crab exosomes showed anti cancer effects on 2&3D models of BC. 3D model of BC showed greater drug resistance than the 2D model after treating with crab derived exosomes and DOX. 3D model of BC mimics native tumor better than 2D and can be used in cancer studies and for drug screening with greater confidence than 2D model. Also, the use of slow release drug delivery system reduced drug resistance in both models.

Mesenchymal stem cell (MSC)-derived exosomes as a cell-free therapy for patients Infected with COVID-19: Real opportunities and range of promises

There are no commercially available effective antiviral medications or vaccines to deal with novel coronavirus disease (COVID-19). Hence there is a substantial unmet medical need for new and efficacious treatment options for COVID-19. Most COVID-19 deaths result from acute respiratory distress syndrome (ARDS). This virus induces excessive and aberrant inflammation so it is important to control the inflammation as soon as possible. To date, results of numerous studies have been shown that mesenchymal stem cells and their derivatives can suppress inflammation. Exosomes function as intercellular communication vehicles to transfer bioactive molecules (based on their origins), between cells. In this review, the recent exosome-based clinical trials for the treatment of COVID-19 are presented. Potential therapy may include the following items: First, using mesenchymal stem cells secretome. Second, incorporating specific miRNAs and mRNAs into exosomes and last, using exosomes as carriers to deliver drugs.

The effect of oleuropein on apoptotic pathway regulators in breast cancer cells

In spite of advancements in breast cancer therapy, this disease is still one of the significant causes of women fatalities globally. Dysregulation of miRNA plays a pivotal role in the initiation and progression of cancer. Therefore, the administration of herbal compounds with anticancer effects through controlling microRNA expression can be considered as a promising therapy for cancer. Oleuropein is the most prevalent phenolic compound in olive. Given its domestic consumption, low cost, and nontoxicity for human beings, oleuropein can be used in combination with the standard chemotherapy drugs. To this end, we examined the effect of oleuropein on two breast cancer cell lines (MCF7 and MDA-MB-231). Our findings revealed that oleuropein significantly decreased cell viability in a dose- and time-dependent manner, while it increased the apoptosis in MCF7 and MDA-MB-231 cells. In the presence of oleuropein, the expression levels of miR-125b, miR-16, miR-34a, p53, p21, and TNFRS10B increased, while that of bcl-2, mcl1, miR-221, miR-29a and miR-21 decreased. The findings pointed out that oeluropein may induce apoptosis via not only increasing the expression of pro-apoptotic genes and tumor suppressor miRNAs, but also decreasing the expression of anti-apoptotic genes and oncomiR. Consequently, oleuropein can be regarded as a suitable herbal medication for cancer therapy.

Does survivin overexpression enhance the efficiency of fibroblast cell-based wound therapy?

Cell-based wound therapy is faced with some limiting factors that decrease the therapeutic efficacy of transplanted cells. In this study, we aimed to genetically modify fibroblast cells with anti-apoptotic Survivin gene (Birc5) before cell transplantation. In vitro, pIRES2-eGFP-Survivin plasmid was transfected into the fibroblast cells and the growth curve was evaluated for transfected and normal cells performing MTT assay. In vivo, two 6-diameter cutaneous wounds were created at mice dorsal skin. Fibrin clot was used as a delivery vehicle to transfer cells into the wound bed. The effects of four treatment groups including (a) Cell-SVV-Clot (b) Cell-GFP-Clot, (c) Normal cell-Clot and, (d) Clot alone were evaluated. After 1,2,3,7 and 14 days post-transplantation, the wounds were photographed for evaluating the wound closure rate and wound samples were obtained. Angiogenesis and formation of granulated tissue were assessed via H&E staining for wound samples. The expression levels of Survivin, VEGF, and bFGF genes were also determined using qRT-PCR. The MTT assay showed similar proliferation potential of transfected cells with normal cells verifying that Survivin had no detrimental effect. Compared to the Normal cell-Clot group, the Survivin overexpression was seen for 3 days in the Cell-SVV-Clot group verifying the cell survival during the early stage of wound healing. The Survivin further upregulated VEGF and bFGF expressions resulting in more angiogenesis and formation of granulated tissue by day 3 and 14. The treated wounds with Cell-SVV-Clot were regenerated with a higher wound closure rate by day 7 compared to Normal cell-Clot and Clot groups. Survivin enhanced wound healing through induction of VEGF and bFGF at particular times post-wounding that led to a more structured-epidermis with higher angiogenesis and granulation tissue formation rate.

SAT0359 THE ASSOCIATION BETWEEN IMAGING SUB-PHENOTYPES OF PSORIATIC ARTHRITIS AND GENE EXPRESSION PROFILES

Background:

Heterogeneity is a hallmark of psoriatic arthritis (PsA), which is reflected in diverse clinical, imaging and molecular features that may reflect disease course and response to treatment. We hypothesized that specific molecular pathways underlie the various manifestations of PsA.

Objectives:

To create a model for accurate and biologically meaningful sub-phenotyping of PsA using imaging and molecular data. Specifically, we aimed to identify imaging sub-phenotypes in patients with PsA and determine their association with whole blood mRNA expression markers.

Methods:

55 patients with PsA ready to initiate treatment for active disease were prospectively recruited. An ultrasound assessment of the extent of musculoskeletal inflammation in 64 joints, 34 tendons and 16 entheses was performed. Sonographic inflammation (in greyscale and Doppler) of the following domains was graded for: a) synovitis; b) peri-tendonitis; c) tenosynovitis; and d) enthesitis. A global inflammatory score was calculated for each tissue domain. Peripheral blood was profiled with RNAseq, and gene expression data were obtained. Analyses were performed in two stages: 1) Unsupervised cluster analysis was performed using hierarchial and k-means to define imaging sub-phenotypes in PsA that reflected the predominant tissue involved; 2) Principal component analysis with ellipses was used to determine the association between imaging-defined clusters and peripheral blood gene expression profile.

Results:

The patients could be divided into 3 groups based on unsupervised hierarchical and k-means clustering of images indicating the predominant involved tissue (Figure 1): 1) Enthesitis predominant (N=13 [24%]); 2) Peri-tendonitis predominant (N=11 [20%]); 3); Synovitis predominant (N=31 [56%]). Patients in the synovitis predominant group had more nail involvement, while those in the peri-tendonitis group had the highest number of clinically active joints (Table 1). Unsupervised clustering of gene expression data identified three clusters that partially overlapped with the imaging clustering (Figure 2). Overall, 344 genes were differentially expressed (p<0.05) in two of the three comparisons between the imaging clusters.

Table 1.

Clinical Features by Imaging Clustering

VariableEnthesitis predominantcluster(N=13)Peritendonitis predominant cluster(N=11)Synovitis predominant cluster(N=31)Age (years)47 (14)49 (16)45 (20)Sex: Female8 (61.5%)5 (45.5%)15 (48.4%)PsA duration (years)1.2 (1.5)1.6 (11.5)0.8 (3.7)BMI29.4 (6.8)25 (8.1)26.1 (8.4)Nail lesions3 (23.1%)5 (45.5%)17 (54.8%)PASI1.2 (2.7)1.2 (3.2)2.8 (7.8)Tender joint count6 (9)11 (5)3 (6)Swollen joint count2 (6)10 (7)3 (6)Dactylitis3 (23.1%)4 (36.4%)7 (22.6%)Enthesitis count3 (3)1 (4)0 (2)Enthesitis12 (92.3%)7 (63.6%)15 (48.4%)hsCRP2.9 (8.8)8.5 (21.5)3.6 (9.4)

Median (IQ range) and frequencies (%)

Bolded=Statistically different between the 3 groups (p<0.05)

Conclusion:

We identified three different imaging clusters based on the predominant tissue involved in patients with active PsA. Distinct gene expression profiles may underlie these imaging clusters seen in PsA.

Acknowledgments:

The study was supported by a Discovery Grant from the National Psoriasis Foundation.

Disclosure of Interests:

Lihi Eder Grant/research support from: Abbvie, Lily, Janssen, Amgen, Novartis, Consultant of: Janssen, Speakers bureau: Abbvie, Lily, Janssen, Amgen, Novartis, Quan Li: None declared, Sara Rahmati: None declared, Iris Eshed: None declared, Proton Rahman Grant/research support from: Janssen and Novartis, Consultant of: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, and Pfizer., Speakers bureau: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, Pfizer, Igor Jurisica Grant/research support from: IBM, Vinod Chandran Grant/research support from: Abbvie, Celgene, Consultant of: Abbvie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lily, Janssen, Novartis, Pfizer, UCB, Employee of: Spouse employed by Eli Lily

OP0305 RHO-GTPASE PATHWAYS MAY DIFFERENTIATE RESPONDER AND NON-RESPONDERS TO TUMOUR NECROSIS FACTOR INHIBITOR (TNFI) AND INTERLEUKIN-17A INHIBITOR (IL-17AI) THERAPY IN PSORIATIC ARTHRITIS (PSA)

Background:

In PsA there is a pressing need to develop a coherent strategy for identifying initial and subsequent biologic responders. PsA patients present substantial heterogeneity in response to biologics, and molecular subtyping will help to identify the right patient for the right treatment.

Objectives:

To identify transcript profiles (biomarkers) that will select TNFi and IL-17Ai responders in PsA using baseline CD4+ cells; and elucidate novel signaling pathways relevant to biologic disease modifying antirheumatic drug (bDMARD) response using a systems biology approach.

Methods:

Consenting patients initiating TNFi agents (20 patients) or IL-17Ai agents (20 patients) with moderate-to-severe PsA were assessed with a comprehensive standardized protocol at baseline and at 3 months. Responder to bDMARDs was defined by Disease Activity index for PSoriatic Arthritis (DAPSA) score of less than 14 (low disease activity). Global transcript profiling was performed on all patients prior to initiation of and 3 months post bDMARDs. We mapped RNA-seq reads to the hg19 reference genome using STAR and quantified transcripts with Cufflinks. The transcripts per million (TPM) values were log-transformed for statistical analyses

Results:

The demographics of PsA patients for both treatment groups are presented (Table 1). Differentially expressed genes (DEGs) were identified using the limma tool for TNFi and IL-17Ai responders and non-responders (Figure 1) as well as DEGs that differentiated TNFi from IL-17Ai response and non-response. Integration of differential gene expression data with tissue-specific protein-protein interactions (IID version 2018-11) identified 117 and 132 DEGs between responders and non-responders to TNFi and IL-17Ai treatments, respectively. Comprehensive pathway enrichment analysis of these genes using pathDIP (v 4.1) revealed 576 (out of 5380) pathways enriched in 117 DEGs between responders and non-responders to TNFi, and 125 pathways enriched in 132 DEGs between responders and non-responders to IL-17Ai. Interestingly, while these two gene lists share only 17 genes, they have 79 enriched pathways in common suggesting potential effect of two different treatments on similar pathways but through different pathway members (Figure 2). Moreover, it suggests potential importance of the 17 shared genes in association with these pathways. Most of these pathways are related to innate and adaptive immune system, and to “osteoclast differentiation”. Among 46 pathways specific to response to IL-17Ai, multiple Rho-GTPase-related pathways were identified. It has been shown that experimental inhibition of ROCK2, a target of Rho-GTPase family is effective in psoriatic disease through regulation of IL-17/23/10, but not IL-6 and TNFα.

Table 1.

Demographics of psoriatic arthritis (PsA) patients.

IL-17AiTNFiNumber of PsA patients2020Gender (% female)55%75%Mean Age (Years)55.9 (9.5)56.8 (7.9)Mean Disease Duration (Years)10.4 (6.9)7.3 (7.9)Mean DAPSA baseline38.8 (17.5)45.6 (28.9)Responders (%) (DAPSA <14)35%65%Biologic naïve (%)40%60%Figure 1.

PCA plots illustrating that DEGs of CD4+ cells can differentiate responders from non-responders when treated with:A.IL-17Ai; andB.TNFi.

Figure 2.

Over-represented terms in significantly enriched pathways considering DEGs between:A.IL-17i responders and non-responders (125 pathways);B.TNFi responders and non-responders (576 pathways).

Conclusion:

Integration of cell-specific transcriptomic data with protein networks represents a very promising strategy for identifying biologic responders and pathways involved in predicting response that may have identified the Rho-GTP pathway as a potential marker to guide the choice of biologic agents for individual patients.

Disclosure of Interests:

Sara Rahmati: None declared, Darren O’Rielly: None declared, Quan Li: None declared, Dianne Codner: None declared, Amanda Dohey: None declared, Kari Jenkins: None declared, Igor Jurisica Grant/research support from: IBM, Dafna D Gladman Grant/research support from: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – grant/research support, Consultant of: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – consultant, Vinod Chandran Grant/research support from: Abbvie, Celgene, Consultant of: Abbvie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lily, Janssen, Novartis, Pfizer, UCB, Employee of: Spouse employed by Eli Lily, Proton Rahman Grant/research support from: Janssen and Novartis, Consultant of: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, and Pfizer., Speakers bureau: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, Pfizer

An overview of current knowledge in biological functions and potential theragnostic applications of exosomes

Exosomes are cup-shaped structures, made of two lipid layers. Their size is in the range of 30-150 nm. Exosomes are excreted to the extracellular space and function in local and systemic cellular communication. Based on their primary origins, they can contain substantial amounts of RNA, protein, and miRNA; the horizontal transfer of these contents significantly determines the exosome's biological effects. The endosomal origins of exosomes can be deduced based on their surface protein markers. The use of exosomes as a diagnostic biomarker and therapeutic tool, has numerous advantages because they do not pose risks such as aneuploidy and transplant rejection. This - overview highlights the recent findings in exosome development and current knowledge in exosome-based therapies.

A combined panel of circulating microRNA as a diagnostic tool for detection of the non-small cell lung cancer

BACKGROUND

Recently, much attention has been paid to use circulating microRNAs (miRs) as a non-invasive tumor marker. The present study for the first time was designed to evaluate concurrent use of miR-21, miR-638, miR148 and miR-152 as putative diagnostic tool for detection of non-small cell lung carcinoma (NSCLC).

METHODS

Forty-three patients diagnosed as primary NSCLC was included in this study. The level of selected miRs was measured in whole blood specimens of patients and controls. The corresponding values were also obtained in stages I-IV. We also assessed possible correlation between selected miRs and the clinicopathological findings of studied individuals.

RESULTS

miR-21 was increased in patients compared to controls (P = 0.004). In contrast, circulating miR-638, miR-148 and miR-152 was observed to be down-regulated in NSCLC patients than controls (P = 0.001, 0.003, 0.053, respectively). Rise in miR-21-5p expression and decreased blood level of miR-148a-3p was associated with higher stage of NSCLC. The highest sensitivity (90%) was observed for miR-21 while miR-148 had the highest specificity (71%). The corresponding sensitivity and specificity for combined-miRs-panel was 96.4% and 86.67%, respectively.

CONCLUSION

In summary, our data suggested the diagnostic importance of combined-miR-panel including miR-21, miR-638, miR148 and miR-152 for effective discrimination of NSCLC from non-cancerous subjects.

A review on different methods to increase the efficiency of mesenchymal stem cell-based wound therapy

Mesenchymal stem cells (MSCs) accelerate wound healing but the harsh environment of wound site limits the engraftment, retention, and survival rate of transplanted cells. There are multiple approaches that amplify the therapeutic potential of MSCs. The MSCs derived from medical waste material, provide comparable regenerative abilities compared to traditional sources. The application of different scaffolds increases MSC delivery and migration into the wound. The spheroid culture of MSC increases the paracrine effects of the entrapped cells and the secretion of pro-angiogenic and anti-inflammatory cytokines. The MSC pretreating and preconditioning enhances the cell migration, proliferation, and survival rate, which lead to higher angiogenesis, re-epithelialization, wound closure, and granulation tissue formation. Moreover, genetic modification has been performed in order to increase MSC angiogenesis, differentiation potential, as well as the cell life span. Herein, we review the results of aforementioned approaches and provide information accommodating to the continued development of MSC-based wound therapy in the future.

Micro-Residual Stress Measurement in Nanocomposite Reinforced Polymers

In the present study, residual stress is measured in fiber-reinforced SWCNT/epoxy at weight fractions of 0.1% and 0.5% with a cross-ply layup on a micro-scale. The mechanical properties of the SWCNT/epoxy composites were determined by tensile testing and the Young's modulus of the epoxy increased moderately with the addition of CNTs. The micro-residual stress of the cross-ply CF/epoxy and CNF-reinforced CF/epoxy laminates were measured using a new experimental approach. The micro-hole was milled by laser beam and the surface displacement was recorded by SEM after milling. In order to determine the residual stress from the recorded strain, the calibration matrix was calculated using the finite element method. The residual stress was obtained at a certain hole depth of specimens. The reliability of this approach was assessed by comparing the residual stress measurements from this method and from the standard hole-drilling method. The experimental results of the present approach confirmed that laser hole drilling SEM-DIC has excellent potential as a reliable method for measuring residual stress in polymer nanocomposites. Generally, CNT agglomerates, especially in high weight fractions, increased the micro-residual stress. An analytical method based on classical theory was used to calculate the residual stress and was compared with the experimental results. Good agreement was found between the results of the analytical methods and the experimental measurement.

Association of p53 codon 72 Arg>Pro polymorphism and risk of cancer in Iranian population: A systematic review and meta-analysis

Background: Different studies have investigated the association between p53 codon 72 Arg>Pro polymorphism and cancer risk. Because of the lack of consensus of the results in individual studies, we conducted this meta-analysis by pooling all currently available case-control studies to estimate the effect of p53 codon 72 Arg/Pro polymorphism on cancer susceptibility in Iranian population. Methods: A comprehensive search was undertaken and primary data from all peer-reviewed journals indexed in PubMed, Google Scholar, Scopus, Magiran, Scientific Information Databank (SID), Iran Medex, and CAB abstract electronic were used to conduct this meta-analysis. We considered some exclusion and inclusion criteria to select the articles. Statistical heterogeneity was explored using the I-square. Publication bias was assessed graphically and statistically by Begg's funnel plot and Egger test. All statistical analyses were performed using StatsDirect software and a two- tailed test. P-value less than 0.05 was considered statistically significant for any test. Results: Our dataset, which included 35 case-control studies, consisted of 2426 cancer cases and 2928 controls. Pooled OR and 95%CI indicated that codon 72 Arg>Pro polymorphism was not associated with odds of developing cancer among Iranian population in the dominant model (Pro/Pro+Arg/Pro vs. Arg/Arg: OR= 0.96, 95%CI= 0.74 to 1.24 chi2= 0.06, p= 0.8). Moreover, no significant association was detected in variant allele (Pro vs Arg: OR= 1.075, 95%CI= 0.91 to 1.25), homozygous (Pro/Pro vs Arg/Arg: OR=0.911 95%CI= 0.66 to 1.25), and heterozygous (Arg/Pro vs Arg/Arg: OR= 0.84, 95%CI= 0.7 to 1). Conclusion: Our study revealed that p53 codon 72 Arg>Pro polymorphism was not associated with overall cancer odds in Iranian population.

Expression profile of ZFX isoform3/variant 5 in gastric cancer tissues and its association with tumor size

OBJECTIVES

Previous studies demonstrate that changes in pre-mRNA splicing play a significant role in human disease development. Furthermore, many cancer-associated genes are regulated by alternative splicing. There are mounting evidences that splice variants which express predominantly in tumors, have clear diagnostic value and may provide potential drug targets. Located on the X chromosome, ZFX gene functions as a transcription regulator for self-renewal of stem cells. This gene has 5 splice variants that encode 3 isoforms. In the present study, we evaluated the clinicopathological relevance of the expression of ZFX isoform 3/variant 5 gene in gastric carcinoma.

MATERIALS AND METHODS

A total of 60 tumoral and non-tumoral gastric specimens were evaluated for ZFX isoform 3/variant 5 gene expression using quantitative real-time PCR.

RESULTS

Our results showed that the expression of ZFX isoform 3/variant 5 transcript was heterogeneous in gastric specimens. We further showed that there was a positive correlation between the variant expression and tumor size, but not with other clinicopathological features of gastric tumors.

CONCLUSION

This report shows that the expression of ZFX isoform 3/variant 5 transcript was heterogeneous in gastric specimens. Furthermore, there was no significant association between ZFX isoform 3/variant 5 expression and most of clinicopathological features of gastric tumors except for a positive correlation with tumor size. The elucidation of the precise molecular mechanisms governed by the ZFX isoforms/variants needs further investigation.

EYA1 expression in gastric carcinoma and its association with clinicopathological characteristics: a pilot study

As the second most frequent cause of cancer death, gastric cancer is a common disease worldwide. Most of the patients are being diagnosed in the stage that conventional treatments are not effective, and invasion and metastases lead to death. So, identification of novel molecular markers to improve early diagnosis, prognosis and treatment of the gastric cancer is a necessity. EYA1 is a member of EYA family which their deregulation has been demonstrated in several types of cancer. The aim of this study was to assess EYA1 gene expression in tissues of the gastric cancer patients and to investigate its correlation with clinicopathological parameters. A total of 60 tumor and non-tumor gastric specimens were evaluated for EYA1 gene expression using quantitative real-time PCR. The EYA1 expression decreased significantly in gastric tumor tissues compared with adjacent normal tissues. We further showed that there was a negative correlation between the EYA1 gene expression levels, tumor size, lymphatic invasion and distant metastasis. In conclusion, EYA1 might be used as a potential biomarker for monitoring gastric carcinoma progression rate. Further studies to determine the mechanism of action of EYA1 is needed to unravel the role of this gene in gastric cancer pathogenesis.

Topoisomerase IV, alone, unknots DNA in E. coli

Knotted DNA has potentially devastating effects on cells. By using two site-specific recombination systems, we tied all biologically significant simple DNA knots in Escherichia coli. When topoisomerase IV activity was blocked, either with a drug or in a temperature-sensitive mutant, the knotted recombination intermediates accumulated whether or not gyrase was active. In contrast to its decatenation activity, which is strongly affected by DNA supercoiling, topoisomerase IV unknotted DNA independently of supercoiling. This differential supercoiling effect held true regardless of the relative sizes of the catenanes and knots. Finally, topoisomerase IV unknotted DNA equally well when DNA replication was blocked with hydroxyurea. We conclude that topoisomerase IV, not gyrase, unknots DNA and that it is able to access DNA in the cell freely. With these results, it is now possible to assign completely the topological roles of the topoisomerases in E. coli. It is clear that the topoisomerases in the cell have distinct and nonoverlapping roles. Consequently, our results suggest limitations in assigning a physiological function to a protein based upon sequence similarity or even upon in vitro biochemical activity.

Isothermic hemodialysis and ultrafiltration

The increase in patient temperature during hemodialysis is explained by hemodynamic compensation during ultrafiltration and hypovolemia that leads to peripheral vasoconstriction and reduced heat losses. We analyzed 51 stable high-efficiency hemodialysis treatments in 27 patients during isothermic dialysis in which body temperature was maintained at a constant level (+/-0.1 degrees C) using the temperature-control option of the Blood Temperature Monitor (BTM; Fresenius Medical Care, Bad Homburg, Germany). Hemodialysis was delivered using ultrapure water (limulus amebocyte lysate test < 0. 06 endotoxin units/mL) at mean blood flows of 410 +/- 40 mL/min. During treatments lasting 178 +/- 23 minutes, 4.8% +/- 1.4% of postdialysis body weight (W%) and 9.5% +/- 2.5% of postdialysis body water were removed using mean ultrafiltration rates of 1.1 +/- 0.3 L/h. Dialysate temperatures significantly decreased from 35.9 degrees C +/- 0.3 degrees C to 35.6 degrees C +/- 0.6 degrees C during hemodialysis. During these treatments, 187 +/- 69 kJ of thermal energy were removed from the patients through the extracorporeal circulation using cool dialysate. Extracorporeal heat flow was 17 +/- 6 W. Energy expenditure (H) estimated from anthropometric data was 65 +/- 12 W. Thus, 28% +/- 10% of estimated energy expenditure (H%) was removed during isothermic dialysis. A highly significant correlation was observed between H% and W% (H% = -5.6 * W%; r(2) = 0.91; P < 0.0001). This result is in support of the volume hypothesis of intradialytic heat accumulation and provides a rule of thumb to estimate extracorporeal cooling requirements for isothermic dialysis. Approximately 6% of H must be removed through the extracorporeal circulation for each percent of ultrafiltration-induced body-weight change. The importance of body temperature control during hemodialysis increases with increased ultrafiltration requirements.

Structure-function analysis of the mammalian DNA polymerase beta active site: role of aspartic acid 256, arginine 254, and arginine 258 in nucleotidyl transfer

The crystal structure of the catalytic domain of rat DNA polymerase beta revealed that Asp256 is located in proximity to the previously identified active site residues Asp190 and Asp192. We have prepared and kinetically characterized the nucleotidyl transfer activity of wild type and several mutant forms of human and rat pol beta. Herein we report steady-state kinetic determinations of KmdTTP, Km(dT)16, and kcat for mutants in residue Asp256 and two neighboring residues, Arg254 and Arg258, all centrally located on strand beta 7 in the pol beta structure. Mutation of Asp256 to alanine abolished the enzymatic activity of pol beta. Conservative replacement with glutamic acid (D256E) led to a 320-fold reduction of kcat compared to wild type. Replacement of Arg254 with an alanine (R254A) resulted in a 50-fold reduction of kcat compared to wild type. The Km(dT)16 of D256E and R254A increased about 18-fold relative to wild type. Replacement of Arg254 with a lysine resulted in a 15-fold decrease in kcat, and a 5-fold increase in the Km(dT)16. These kinetic observations support a role of Asp256 and Arg254 in the positioning of divalent metal ions and substrates in precise geometrical orientation for efficient catalysis. The mutation of Arg258 to alanine (R258A) resulted in a 10-fold increase in KmdTTP and a 65-fold increase in Km(dT)16 but resulted in no change of kcat. These observations are discussed in the context of the three-dimensional structures of the catalytic domain of pol beta and the ternary complex of pol beta, ddCTP, and DNA.

RNase D, a reported new activity associated with HIV-1 reverse transcriptase, displays the same cleavage specificity as Escherichia coli RNase III

RNase D was recently reported as a new enzymatic activity associated with HIV-1 reverse transcriptase (RT), cleaving RNA at two positions within the double-stranded region of the tRNA primer-viral RNA template complex (Ben-Artzi et al., Proc. Natl. Acad. Sci. USA 89 (1992) 927-931). This would make RNase D a fourth distinct activity of HIV-1 RT, in addition to RNA- and DNA-dependent DNA polymerase and RNase H. Using a specific substrate containing tRNA(Lys,3) hybridized to the primer binding site, we were able to detect the reported RNase D activity in our preparations of recombinant HIV-1 RT. This activity was also present in several active-site mutants of RT, suggesting that it is independent of the RNase H and polymerase functionalities of RT. Furthermore, we found that the cleavage specificity of RNase D is the same as that of RNase III isolated from E.coli. A likely explantation of these results--that the observed RNase D activity is attributable to traces of RNase III contamination--was further strengthened by the finding that the recombinant preparations of HIV-1 RT can specifically cleave a phage T7-derived double-stranded RNA processing signal, which has been used as a model substrate for detection of E.coli RNase III. Moreover, RT purified from an RNase III- strain of E.coli displayed no cleavage of the tRNA primer-RNA template complex.