Rheumatoid arthritis: the old issue, the new therapeutic approach.

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease of unknown etiology. The most common form of this disease is chronic inflammatory arthritis, which begins with inflammation of the synovial membrane of the affected joints and eventually leads to disability of the affected limb. Despite significant advances in RA pharmaceutical therapies and the availability of a variety of medicines on the market, none of the available medicinal therapies has been able to completely cure the disease. In addition, a significant percentage (30-40%) of patients do not respond appropriately to any of the available medicines. Recently, mesenchymal stromal cells (MSCs) have shown promising results in controlling inflammatory and autoimmune diseases, including RA. Experimental studies and clinical trials have demonstrated the high power of MSCs in modulating the immune system. In this article, we first examine the mechanism of RA disease, the role of cytokines and existing medicinal therapies. We then discuss the immunomodulatory function of MSCs from different perspectives. Our understanding of how MSCs work in suppressing the immune system will lead to better utilization of these cells as a promising tool in the treatment of autoimmune diseases.

Comparison of Ultrasound-Guided Percutaneous and Open Surgery Approaches in The Animal Model of Tumor Necrosis Factor-Alpha-Induced Disc Degeneration.

OBJECTIVE: Animal models provide a deeper understanding about various complications and better demonstrate the effect of therapeutic approaches. One of the issues in the low back pain (LBP) model is the invasiveness of the procedure and it does not mimic actual disease conditions in humans. The purpose of the present study was to compare the ultrasound-guided (US-guided) percutaneous approach with the open-surgery method in the tumor necrosis factor-alpha (TNF-α)-induced disc degeneration model for the first time to showcase the advantages of this recently developed, minimally invasive method. MATERIALS AND METHODS: In this experimental study, eight male rabbits were divided into two groups (open-surgery and US-guided). Relevant discs were punctured by two approaches and TNF-α was injected into them. Magnetic resonance imaging (MRI) was performed to assess the disc height index (DHI) at all stages. Also morphological changes (annulus fibrosus, nucleus pulposus) were evaluated by assessing Pfirrmann grade and histological evaluation (Hematoxylin and Eosin). RESULTS: The findings indicated targeted discs became degenerated after six weeks. DHI in both groups was significantly reduced (P<0.0001), however the difference was not significant between the two groups. In the open-surgery group, osteophyte formation was seen at six and eighteen weeks after the puncture. Pfirrmann grading revealed significant differences between injured and adjacent uninjured discs (P<0.0001). The US-guided method indicated significantly fewer signs of degeneration after six (P=0.0110) and eighteen (P=0.0328) weeks. Histological scoring showed significantly lower degeneration in the US-guided group (P=0.0039). CONCLUSION: The US-guided method developed a milder grade condition and such a model better mimics the chronic characteristics of LBP and the procedure is more ethically accepted. Therefore, the US-guided method could be a merit approach for future research in this domain as a safe, practical and low-cost method.

Clinical Evaluation of Collagen-Induced Arthritis in Female Lewis Rats: A Comprehensive Analysis of Disease Progression and Severity.

OBJECTIVE: The collagen-induced arthritis (CIA) model is the most commonly studied autoimmune model of rheumatoid arthritis (RA). In this study, we investigated the usefulness of collagen type II emulsified in Freund's incomplete adjuvant (CII/IFA) as a suitable method for establishing RA in Lewis rats. The aim of the present study was to present a straightforward and effective method for inducing CIA in rats. MATERIALS AND METHODS: In this experimental study, animals were divided into two equal groups (n=5); control and CIA. Five rats were injected intradermally at the base of the tail with a 0.2 ml CII/IFA emulsion. On the seventh day, a 0.1 ml CII/IFA emulsion booster was injected. Arthritis symptoms that arose were evaluated at clinical, histological, radiological, and at protein expression levels to find out if the disease had been induced successfully. RESULTS: Our finding showed a decreasing trend in the body weight during the RA induction period, while the arthritis score and paw thickness were increased during this period. The results of the enzyme-linked immunosorbent assay (ELISA) for serum samples revealed that the levels of proinflammatory cytokines, interleukin (IL)-1ß, IL-6, IL-17, and tumor necrosis factor (TNF)-α and anti-CII IgG were significantly increased in CIA rats compared to the control group. After CIA induction, the level of anti-inflammatory protein IL-10 was decreased significantly. Radiographic examination of the hind paws showed soft tissue swelling, bone erosion, and osteophyte formation in CIA rats. Additionally, based on histological evaluations, the hind paws of the CIA group showed pannus formation, synovial hyperplasia, and bone and cartilage destruction. CONCLUSION: It seems that CII/IFA treatment can be an appropriate and effective method to induce RA disease in Lewis rats. This well-established and well-characterized CIA model in female Lewis rats could be considered to study aspects of RA and develop novel anti-arthritic agents.

Long-term passages of human clonal mesenchymal stromal cells can alleviate the disease in the rat model of collagen-induced arthritis resembling early passages of different heterogeneous cells.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease of unknown cause. The interaction of immune system cells and the secretion of inflammatory cytokines with synovial cells leads to severe inflammation in the affected joints. Currently, medications, including non-steroidal anti-inflammatory drugs, glucocorticoids, and more recently, disease-modifying anti-rheumatic drugs, are used to reduce inflammation. However, long-term use of these drugs causes adverse effects or resistance in a considerable number of RA patients. Recent findings revealed the safety and efficacy of mesenchymal stromal cells (MSCs)-based therapies both in RA animal models and clinical trials. Here, the beneficial effects of bone marrow-derived heterogeneous MSCs (BM-hMSCs) and Wharton jelly-derived MSCs (WJ-MSCs) at early passages were compared to BM-derived clonal MSCs (BM-cMSCs) at high passage number on a rat model of collagen-induced arthritis. Results showed that systemic delivery of MSCs significantly reversed adverse changes in body weight, paw swelling, and arthritis score in all MSC-treated groups. Radiological images and histological evaluation demonstrated the therapeutic effects of MSCs. There was a decrease in serum level of anti-collagen type II immunoglobulin G and the inflammatory cytokines interleukin (IL)-1ß, IL-6, IL-17, and tumor necrosis factor-α in all MSC-treated groups. In contrast, an increase in inhibitory cytokines transforming growth factor-ß and IL-10 was seen. Notably, the long-term passages of BM-cMSCs could alleviate RA symptoms similar to the early passages of WJ-MSCs and BM-hMSCs. The importance of BM-cMSCs is the potential to establish cell banks with billions of cells derived from a single donor that could be a competitive cell-based therapy to treat RA.

Standard toxicity study of clinical-grade allogeneic human bone marrow-derived clonal mesenchymal stromal cells.

INTRODUCTION: Mesenchymal stromal cells (MSCs) have opened a new window to treat inflammatory and non-inflammatory diseases. Nonetheless, their clinical applications require rigorous control and monitoring procedures to ensure full compliance with the principles of good manufacturing practice (GMP). Various evaluations should be passed in conjunction with the development of these newly emerging therapeutic products from bench-to-bedside. These evaluations include in vitro characterization, preclinical studies, and clinical trials to ensure product safety and efficacy. Therefore, a robust and well-designed preclinical study is critical to confirm product safety. This study aims to determine the probable toxicity effects of local and systemic injections of cryopreserved human bone marrow-derived clonal MSCs (BM-cMSCs) during subacute and subchronic periods of time. METHODS: BM-cMSCs were characterized according to the International Society for Cell and Gene Therapy (ISCT) criteria for MSCs. Both safety and toxicity of the BM-cMSCs population produced under GMP-compatible conditions were assessed in both sexes of Sprague Dawley (SD) rats via systemic intravenous (IV) administration and local injection in intervertebral disc (IVD). Behavioral changes, clinical signs of toxicity, and changes in body weight, water and food consumption were the important variables for product toxicity testing over 14 consecutive days during the subacute period and 90 consecutive days during the subchronic period. At the end of the assessment periods, the rats were killed for histopathology analysis of the target tissues. The BM-cMSCs potential for tumorigenicity was checked in nude mice. RESULTS: Single IV and IVD injections of BM-cMSCs did not cause significant signs of clinical toxicity, or changes in laboratory and histopathology data during the subacute (14 day) and subchronic (90 day) periods. Ex vivo-expanded and cryopreserved BM-cMSCs did not induce tumor formation in nude mice. CONCLUSION: The results suggest that local and systemic administrations of xenogeneic BM-cMSCs in both sexes of SD rats do not cause toxicity during the subacute and subchronic periods of time. Also, BM-cMSCs were non-tumorigenic in nude mice.

The most common allergens according to skin prick test: The role of wheal diameter in clinical relevancy.

The skin prick test (SPT) could be applied as a useful in vivo method for the detection of sensitization in epidemiological and diagnostic studies if the wheal size is ideally evaluated. We focused on SPT wheal size to identify sensitization pattern to common inhalant and food allergens. In this cross-sectional study, SPT results were obtained from a total of 972 allergic patients. Common allergen extracts for SPT were selected according to the type of allergic diseases, and the geographical pattern. SPT with food allergens was performed for patients with atopic dermatitis (AD) and chronic urticaria (CU). A total of 461 male (47.4%) and 511 female (52.6%) participated in this study (median age: 31 years). The majority of individuals were affected with allergic rhinitis (AR) (n = 624) and asthma (n = 224); while 129 and 67 patients suffered from AD and CU, respectively. The most common aeroallergens were Russian thistle (52.1%) and lamb's quarter (50.7%) with the largest wheal diameter. The wheal size of lamb's quarter was significantly different between patients with asthma and AR (P<.001). In addition, a significant difference was detected in wheal diameter in response to the Russian thistle between patients with AR and AD (P = .001). Shrimp (23.6%) and Peanut (22.5%) caused the most common food sensitization in patients with AD and CU. Having in mind the most common weed pollens including the Russian thistle and lamb's quarter, preventive strategies, such as, removing unwanted weeds or preventing them from growing, avoidance, and specific immunotherapy may be crucial for better disease control.

Assessment of miR-181b-5p, miR-23a-3p, BCL-2, and IL-6 in Peripheral Blood Mononuclear Cells of Autistic Patients; Likelihood of Reliable Biomarkers.

Autism is a neurodevelopmental disorder that is recognized by stereotypic and repetitive behaviors after 2 years of old. Dysregulation of the immune system, especially inflammation which is mostly regulated by IL-6, imposes a deficit in CNS development. Along with this crucial biomarker, researchers have proposed BCL-2, micro RNA-23a-3p (miR-23a-3p), miR-181b-5p as other probable biomarkers involved in inflammation and apoptosis. The aim of the study was to evaluate the alteration in the expression of these biomarkers in a group of autism spectrum disorder (ASD) children. Peripheral blood mononuclear cells (PBMCs) were obtained from 37 autistic patients. After RNA extraction with precipitation method, the Syber green qReal-time Polymerase Chain Reaction (PCR) was performed in order to evaluate the possible alteration in the expression of IL-6, BCL-2, miR-181b-5p, and miR-23a-3p. The results were compared with healthy controls. IL-6 was significantly upregulated in ASD patients (p=0.003). On the other hand, miR-23a was upregulated and BCL-2 downregulated in ASD patients but the changes were not significant. In initial evaluations, expression changes of miR-181b-5p were not statistically significant. However, when Patients were divided into two groups of upregulated and downregulated, re-evaluation showed that both up- (p=0.005) and down-regulation (p=0.004) (i.e. changes regardless of the direction) of miR-181b were significant in autistic children. IL-6 and miR-181b-5p can have proper diagnostic values and are reliable biomarkers with high sensitivity and specificity. On the other hand, PBMC can be utilized for such studies and also evaluation of patients' condition instead of brain tissue as it is less accessible.

Endotoxin and Der p1 allergen levels in indoor air and settled dust in day-care centers in Tehran, Iran.

BACKGROUND: Allergens like endotoxin and mite allergen Der p 1 are associated with early wheezing and asthma morbidity. Day-care centers can be an important source of exposure to allergens. The aim of this study was to evaluate children's exposure to endotoxin and mite allergen (Der p 1) associated with total suspended particulate matter (TSP) and settled dust in day-care centers in two phases in years of 2015 and 2016 in Tehran city, Iran. METHODS: Endotoxin and mite allergen Der p 1 in TSP and settled dust were measured in 23 day-care centers in Tehran. After collecting dust samples and weighting them, and then their extraction, Endotoxin and Der p 1 allergen were determined using QCL-1000 Endpoint chromogenic LAL Assay and ELISA, respectively. RESULTS: The mean concentrations of endotoxin and mite allergen Der p 1 in settled dust were 0.3 EU/mg and 0.2 ng/mg, respectively. The mean concentration of endotoxin and mite allergen Der p 1 in indoor air TSP were 0.8 EU/m3 and 0.4 ng/m3, respectively. A significant negative correlation was found between endotoxin both in settled dust and in TSP with measured relative humidity in winter. Also, moderate correlation was observed between Der p 1 in settled dust and relative humidity in winter; however, the correlation between allergen in TSP and relative humidity was not significant. CONCLUSION: Day-care centers can be an important source of endotoxin and Der p 1 allergen, so, implementation of proper interventions in these places can reduce exposure to them.

The Prevalence of Allergic Rhinitis, Allergic Conjunctivitis, Atopic Dermatitis and Asthma among Adults of Tehran.

BACKGROUND: Alteration of environmental factors and air pollution affects the trend of allergic diseases especially in cities such as Tehran. This study aimed to determine the prevalence of allergic rhinitis, conjunctivitis, atopic dermatitis and asthma among adults in the capital city of Iran. METHODS: This cross-sectional study was performed between 2013 and 2016 in Tehran, Iran. The participants were adults between 18 and 45 yr of age. A specific questionnaire including demographic data and clinical symptoms was filled out by a trained interviewer. The diagnosis of allergic diseases was performed based on standard questionnaires and criteria. RESULTS: The prevalence of allergic rhinitis, conjunctivitis, asthma and atopic dermatitis were 28.3%, 15.9%, 7.6% and 3.9%, respectively. Allergic rhinitis and conjunctivitis together were reported in 12.3% of the participants. Among patients with asthma, 47.4% had AR. Additionally, 25.7% of atopic dermatitis subjects were reported to have asthma. The subjects with at least one of these allergic diseases were 36.3%. Women showed a higher prevalence of allergic symptoms than men. There was a significant relationship between allergic symptoms and family history of atopic diseases. CONCLUSION: The most common allergic disease was allergic rhinitis. Regarding the comorbidity of asthma and allergic rhinitis, paying more attention to controlling these allergic diseases is deemed necessary.

The potential anti-inflammatory role of adiponectin in food allergy: a case-control study on children.

We aimed to assess the possible relationship between food allergy and two key adipokines - leptin and adiponectin - in children with food allergy. A total of forty patients with definite diagnosis of food allergy according to clinical history and specific IgE (sIgE) for food allergens (group I) were enrolled in this pilot study. The control group (group II) included thirty children with no evidence of allergic symptoms. Serum levels of leptin and adiponectin were measured by ELISA. Meanwhile, sIgE was measured for the eight most common food allergens by the immunoblot method in all participants. The median ages in groups I and II were 18·5 and 23·5 months, respectively. The respective Caesarean section rate was 64·9 and 16·7 % in groups I and II (P<0·001). Serum levels of adiponectin were significantly higher in the patient group compared with controls (24·11 (sd 12·14) v. 10·67 (sd 12·23) µg/ml, P<0·001), whereas no statistically meaningful difference was detected in serum leptin concentrations (P=0·92). There was a significant inverse relationship between age and adiponectin levels in group I (P=0·002, r -0·479) and group II (P=0·04, r -0·365), and it was more significant in group I. The most common allergens in the patient group were wheat (52·5 %), hazelnut (52·5 %), cow's milk (50 %) and egg white (30 %). The results of this study suggest an essential link between adiponectin and food allergy that is probably unlikely to be affected by obesity as a confounding factor.

IgE Sensitization to Inhalant Allergens and Its Association with Allergic Diseases in Adults.

Allergic sensitization to inhalant allergens could be considered as a predictor in allergic diseases. The objective of this study was to assess IgE-mediated sensitization to inhalant allergens in allergic and non-allergic adults as well as the evaluation of its association with allergic diseases. This cross-sectional study was conducted from 2013 to 2016 in 604 allergic and 102 non-allergic adults selected from blood donor volunteers in Tehran, Iran. After taking informed consent, a standard questionnaire was filled to determine asthma, allergic rhinitis and/or conjunctivitis and atopic dermatitis in participants. Specific IgE assay to common inhalant allergens was performed for all subjects. Logistic regression analysis was used to evaluate the impact of IgE sensitization on allergic diseases. A total of 371(61.4%) allergic subjects and 41(40.2%) non-allergic patients were males. The weeds (especially saltwort) and grasses (particularly meadow fescue and ryegrass) were identified as the most common inhalant allergens. The prevalence of IgE sensitization to trees, weeds, and grasses was higher in subjects with allergic rhino-conjunctivitis and trees sensitization was a significant factor in them [OR=2.32, 95% CI (1.58-3.41)]. IgE sensitization to any inhalant allergens could be a predictor for allergic rhinitis, conjunctivitis and rhino-conjunctivitis in adults [OR=2.20, 95% CI (1.54-3.15], [OR=1.81, 95% CI (1.28-2.54)] and [OR=2.55, 95% CI (1.72-3.78)], respectively. With an increase in the sum of specific IgE concentrations, the prevalence of allergic conjunctivitis and rhino-conjunctivitis also increased. Our results showed the association between positive specific IgE and its concentration with some allergic diseases which could help physicians to prevent such diseases by recognizing and treating them, particularly in individuals with a positive family history of allergic diseases.

Accuracy of immunoblotting assay for detection of specific IgE compared with ImmunoCAP in allergic patients.

BACKGROUND AND AIM: Standardized techniques help us to better diagnosis and follow up of allergic diseases. In this study, we determined the sensitivity, accuracy, and specificity of an Immunoblotting test compared to ImmunoCAP as the reference in vitro test for detection of specific IgE in allergic patients. METHODS: In this cross-sectional study, specific IgE level was determined in patients with allergic symptoms who referred to the Immunology, Asthma and Allergy Research Institute, Tehran, Iran from 2010-2016, by two techniques. Eleven different allergens (six aeroallergens and five food allergens) were determined, and 303 specific IgE tests were performed for the patients by each method. The Immunoblotting test is a multiplex assay on a nitrocellulose membrane coated with 20 selected allergens. ImmunoCAP is considered as the reference method for determination of in vitro specific IgE. Its principle is an automated sandwich immunoassay, and allergens were bound to the solid phase, covalently. Finally, the fluorescence of elute was determined. Specific IgE more than 0.35 KU/L was considered as a positive test. Sensitivity, specificity, accuracy, kappa coefficient, positive and negative likelihood ratio (+/- LR), and correlation coefficient (calculated with Spearman test) between two tests were determined using statistical analysis (SPSS software, version 18). RESULTS: One hundred and thirty five patients entered this study. The median age of the patients was 3.75 years with the males constituting 54.8% of the population. The most common cheif complaints were respiratory (51.6%), skin (41.8%) and gastrointestinal (27.9%) symptoms, respectively. The sensitivity, specificity, accuracy, +LR and -LR were 83%, 97%, 92%, 27.66 and 0.17, respectively. The kappa coefficient of the immunoblotting test was 0.81 compared to the reference technique. The correlation coefficient for positive tests between the two methods was 0.71 (p<0.001). CONCLUSION: Regarding the presence of 20 allergens in a RIDA allergy panel and according to our findings, this immunoblotting test with high sensitivity could be used as a fast and cost-efficient screening test. However, ImmunoCAP is recommended when the accurate level of specific IgE is required. ImmunoCAP findings are particularly helpful for immunotherapy and the elimination diet.

Determination of the Most Common Indoor and Outdoor Allergens in 602 Patients with Allergic Symptoms Using Specific IgE Local Panel.

Aeroallergens play an important role in developing allergic diseases. The aim of this study was to determine the outdoor and indoor sensitization using a specific regional panel of aeroallergens in allergic patients. All patients with allergic symptoms referred to Immunology, Asthma and Allergy Research Institute (IAARI) in Tehran, Iran from December 2010 to July 2013 entered this cross sectional study. We evaluated serum samples for specific IgE against 20 selected aeroallergens provided by a specific panel (RIDA Allergy Screen test, IAARI panel). A p value less than 0.05 was considered as significant. The patients (n=602) were 49.8 % male and 50.2% female. The median age was 9 years. Positive specific IgE at least to one allergen was 53.2%. The percentages of patients with only outdoor or indoor sensitization were 37.5 and 19.7%, respectively. Moreover, 42.8% showed sensitization to both indoor and outdoor aeroallergens. The most common outdoor aeroallergens in decreasing order were plane tree (32.8%), Bermuda grass (32.2%), timothy grass (30.6%), saltwort (28.4%). The percentage of specific IgE to indoor allergens including mold and mite were 23.8 % and 22.2%, respectively. There was a statistically significant relationship between specific IgE to timothy grass and mold allergens between two genders (p=0.04 and p=0.02, respectively).The results of this study shows that outdoor aeroallergens can be considered as the most common causes of allergic symptoms in our allergic patients.

Modulation of microRNAs expression in hematopoietic stem cells treated with sodium butyrate in inducing fetal hemoglobin expression.

Context Inherited hemoglobin diseases are the most common single-gene disorders. Induction of fetal hemoglobin in beta hemoglobin disorders compensate for abnormal chain and ameliorate the clinical complications. Sodium butyrate is used conventionally for fetal hemoglobin induction; it can be replaced by safer therapeutic tools like microRNAs, small non-coding RNAs that control number of epigenetic mechanisms. Objective In this study, we compared the changes in the microRNAs of differentiated erythroid cells between control and sodium butyrate treated groups. The objective is to find significant association between these changes and gamma chain up regulation. Materials and methods First, CD133+ hematopoietic stem cells were isolated from cord blood by magnetic cell sorting (MACS) technique. After proliferation, the cells were differentiated to erythroid lineage in culture medium by EPO, SCF, and IL3. Meanwhile, the test group was treated with sodium butyrate. Then, gamma chain upregulation was verified by qPCR technique. Finally, microRNA profiling was performed through microarray assay and some of them confirmed by qPCR. Result Results demonstrated that gamma chain was 5.9-fold upregulated in the treated group. Significant changes were observed at 76 microRNAs, in which 20 were up-regulated and 56 were down-regulated. Discussion Five of these microRNAs including U101, hsa-miR-4726-5p, hsa-miR7109 5p, hsa-miR3663, and hsa-miR940 had significant changes in expression and volume. Conclusion In conclusion, it can be assumed that sodium butyrate can up-regulate gamma chain gene, and change miRNAs expression. These results can be profitable in future studies to find therapeutic goal suitable for such disorders.

Evaluation of the Effect of miR-26b Up-Regulation on HbF Expression in Erythroleukemic K-562 Cell Line.

BACKGROUND: The major hemoglobin in the fetus is hemoglobin F (HbF) (α2γ2), whereas in adult humans, hemoglobin A (α2ß2) is predominately expressed. Several studies have indicated that expression of the HbF subunit γ-globin might be regulated post-transcriptionally. This could be done by small non-coding RNAs called microRNAs which target mRNAs in a sequence-specific manner and lead to translational repression or mRNA decay. The aim of this study is to evaluate the effect of miR-26b up-regulation on γ-globin gene expression in K-562 cell line. METHODS: These cells were grown in RPMI 1640 and pre miR-26b and were transfected within K-562 cell line using lentiviral vector. After RNA extraction and cDNA synthesis in selected days, miRNA up-regulation was confirmed by miRNA real time PCR and then γand ßchain and GATA-1 expression were investigated by RT and QRT-PCR. RESULTS: The viability of cells before transfection was 90%. Three and 7 days after transfection, through the use of relative Q-PCR, the γ chain expression increased 3.7, 6.8 and 3.8 folds and GATA-1 expression increased 2.1, 6.0 and 8.0 in comparison with untransfected cells. CONCLUSION: The data suggest that miR-26b can be involved in the increase of γ-globin gene expression in K-562 cell line. We suggest that miR-26b may be a significant therapeutic target for increasing HbF levels in patients with sickle cell disease and ß-thalassemia.

The Effect of miR-210 Up-regulation on Proliferation and Survival of Mouse Bone Marrow Derived Mesenchymal Stem Cell.

BACKGROUND: Bone marrow derived mesenchymal stem cells (MSCs) are a population of multipotent progenitors which have the capacity of proliferation and differentiation into mesenchymal lineage cells. Hypoxia could promote the proliferation of MSCs. Micro-RNAs are endogenous RNAs that can play an important role in some processes such as proliferation and differentiation. MiR-210 could help for better proliferation of MSCs since this miRNA could activate HIF pathway. In current study we investigated if MSCs can preserve their differentiation and proliferation ability under normoxic conditions by upregulation of miR-210. MATERIALS AND METHODS: MSCs isolated from C57 BL/6 mice by flushing it's femurs into the cell culture media. After 72 hours, MSCs which are plastic adherent cells were attached to the flask and non-adherent cells were removed. Subsequently, MSCs induced to differentiate into osteocytes and adipocytes with specific differentiation media in order to confirm their identity and multipotency. Then miR-210 was inserted in Lentiviruse vectors and affected MSCs. In each passage, the number and viability of cells were evaluated. RESULTS: Comparison between miR-210 infected MSCs with control cells showed that miR-210 has ability to increase proliferation of MSCs significantly. CONCLUSION: We showed that miR-210 has ability to induce proliferation of MSCs without any negative effect on their differentiation abilities. Further studies are needed for evaluation of probable effects of miR-210 mechanisms on MSCs proliferation.