Electromagnetic field exposure as a plausible approach to enhance the proliferation and differentiation of mesenchymal stem cells in clinically relevant scenarios / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Mesenchymal stem/stromal cell (MSC)‍-based therapy has been regarded as one of the most revolutionary breakthroughs in the history of modern medicine owing to its myriad of immunoregulatory and regenerative properties. With the rapid progress in the fields of osteo- and musculoskeletal therapies, the demand for MSC-based treatment modalities is becoming increasingly prominent. In this endeavor, researchers around the world have devised new and innovative techniques to support the proliferation of MSCs while minimizing the loss of hallmark features of stem cells. One such example is electromagnetic field (EMF) exposure, which is an alternative approach with promising potential. In this review, we present a critical discourse on the efficiency, practicability, and limitations of some of the relevant methods, with insurmountable evidence backing the implementation of EMF as a feasible strategy for the clinically relevant expansion of MSCs.

Effect of Systemic Administration of Granulocyte-Colony Stimulating Factor on Rate of Fracture Healing of Bone Defect in Goats as Animal Model

@#Granulocyte-colony stimulating factor (G-CSF) serves as an important cytokine in haematopoiesis; released at both physiological and pathological conditions by a range of cells. We hypothesized that the systemic administration of G-CSF would produce an accelerated fracture-healing rate in non-union bone defects; thus, potentially leading to useful clinical applications. Ten male adult Katjang goats, weighing about 15-26 kilograms were randomly chosen and a tibial bone defect was induced in each animal. The defect was maintained by internal fixation with a titanium plate and reinforced by an external fiberglass cast. Post-operative radiographs were performed twice weekly and radiographic assessments were performed by evaluating the bridging and union measurements through a validated method. In the treatment group, the time for bridging and union exhibited statistically significant differences when compared with a control group. The outcomes of the present study establishing a notion that administration of G-CSF besides inducing haematopoiesis, promotes healing of fractures and non-union bone defects as well.

Human Mesenchymal Stem Cells Impair the Proliferation of Monocytes Through Cell Cycle Interference

@#Introduction: Monocytes are essential phagocytic cells of the innate immune system as they are required for the maintenance of tissue homeostasis. However, accumulation of monocytes is implicated in various chronic inflammatory diseases like coronary heart disease, atherosclerosis and in autoimmune disorders. Therefore, the number of monocytes must be carefully regulated to avoid monocyte induced inflammatory disorders. Mesenchymal stem cells (MSCs) have shown to be effective against various inflammatory diseases due to their immunosuppressive properties. The present study was designed to evaluate the less understood immunomodulatory effect of MSCs on monocyte proliferation and survival. Method: Primary monocytes were isolated from peripheral human blood using CD14+ monocyte isolation kit. The in house produced umbilical cord MSCs were co-cultured with monocytes at different ratio and time; assessed for the monocyte viability, proliferation and cell cycle. Results: Mesenchymal stem cells suppressed monocyte proliferation in a dose-dependent manner. The antiproliferative effect of MSCs was mediated by cell cycle arrest, whereby monocytes were arrested in the G0/G1 phase of the cell cycle by preventing them from progress into S and G2/M phases. Although cell cycle arrest could potentially lead to apoptosis; however, MSCs significantly enhanced the monocytes survival and inhibited apoptosis. Conclusion: Human MSCs inhibit the stimulated monocyte proliferation without inducing cellular apoptosis at in vitro. These results reveal that MSCs can be utilised to control monocytes’ quantity during an unwanted immune response to maintain homeostasis.

The Crosstalk between Mesenchymal Stem Cells and Damaged Cartilage in Osteoarthritis

@#Human cartilage contains multipotent stem cells, namely mesenchymal stem cells (MSCs) which are progenitors of connective tissue that play homeostatic and reparative roles. Although the major constituent cells in the cartilage are chondrocytes, they possess a limited regenerative ability, and as a result, spontaneous cartilage repair by chondrocytes leads to the synthesis of fibrocartilage. Similarly, MSCs derived from articular cartilage of osteoarthritis patients have demonstrated inadequacy in cartilage repair. The role of MSCs in the pathophysiology of osteoarthritis (OA) is not entirely understood, whether the inflammatory milieu associated with OA joints affects the reparative properties of MSCs or the inherent defects of OA cartilage-derived MSCs impair the proper execution of the required immunosuppressive and reparative functions. Therefore, the current review explores the biological characteristics and features of MSCs derived from physiological state and OA condition with the aim of identifying how OA affects MSC functions as well as the role of MSCs in the pathophysiology of OA.

Nutritional Compositions and Antiproliferative Activities of Different Solvent Fractions from Ethanol Extract of Cyphomandra betacea (Tamarillo) Fruit

Background: This study aims to examine various solvent extracts of Cyphomandra betacea (tamarillo) also known as the tree tomato, for their bioactive constituents and antioxidant activity. The study also aims to examine its effect on cancer cell death using two types of cancer cell lines (liver and breast cancer cell). Methods: The first part of the study evaluates the nutritional composition of tamarillo. Then, phytochemical profiling using GC-MS analysis in ethanolic tamarillo extract was conducted. Different fractions of n-butanol, ethyl acetate and aqueous fractions were obtained from the ethanolic extract of tamarillo. Then, the fractions were subjected to the quantification of total phenol (TPC) and flavonoid contents (TFC), free radical scavenging activity (SA) and also antioxidant activity (AOX) assayed by beta-carotene bleaching (BCB) assay. Finally, the capability of the ethanolic extract of tamarillo and different fractions were evaluated for their anticancer properties. Results: Findings from this study revealed that the nutritional composition (ash, protein, carbohydrate and total dietary fiber), and mineral levels (calcium, magnesium, potassium and iron) of tamarillo were moderate. The crude ethanol extract of tamarillo contained the highest phenolic and total flavonoid content. FT-IR analysis revealed the presence of alkanes, carboxylic acid, phenol, alkanes, carboxylic acids, aromatics and nitro compounds. Twelve bioactive constituents in tamarillo have been identified through GC-MS analysis. Cytotoxic activity suggests the potential of ethanolic extracts of tamarillo having a chemopreventive effect on breast and liver cancer cells. Conclusion: This study reveals that tamarillo has substantial antioxidant activity as well as anticancer properties.

Differential Expression Patterns of Leukaemia Associated Genes in Leukaemia Cell Lines Compared to Healthy Controls

Introduction: The phenotype and genotype of cancer cells portray hallmarks of cancer which may have clinical value. Cancer cell lines are ideal models to study and confirm these characteristics. We previously established two subtracted cDNA libraries with differentially expressed genes from an acute myeloid leukaemia patient with poor prognosis (PP) and good prognosis (GP). Objective: To compare gene expression of the leukaemia associated genes with selected biological characteristics in leukaemia cell lines and normal controls. Methodology: Expression of 28 PP genes associated with early fetal/embryonic development, HOX-related genes, hematopoiesis and aerobic glycolysis/ hypoxia genes and 36 GP genes involved in oxidative phosphorylation, protein synthesis, chromatin remodelling and cell motility were examined in B-lymphoid (BV173, Reh and RS4;11) and myeloid (HL-60, K562) leukaemia cell lines after 72h in culture as well as peripheral blood mononuclear cells from healthy controls (N=5) using semi-quantitative polymerase chain reaction (PCR) method. Cell cycle profiles were analysed on flow cytometry while MTT cytotoxicity assay was used to determine drug resistance to epirubicin. Results: Genes expressed significantly higher in B-lymphoid leukaemia cell lines compared to healthy controls were mostly of the GP library i.e. oxidative phosphorylation (3/10), protein synthesis (4/11), chromatin remodelling (3/3) and actin cytoskeleton genes (1/5). Only two genes with significant difference were from the PP library. Cancer associated genes, HSPA9 and PSPH (GP library) and BCAP31 (PP library) were significantly higher in the B-lymphoid leukemia cell lines. No significant difference was observed between myeloid cell lines and healthy controls. This may also be due heterogeneity of cell lines studied. PBMC from healthy controls were not in cell cycle. G2/M profiles and growth curves showed B-lymphoid cells just reaching plateau after 72 hour culture while myeloid cells were declining. IC50 values from cytotoxicity assay revealed myeloid cell lines had an average 13-fold higher drug resistance to epirubicin compared to B-lymphoid cell lines. Only CCL1, was expressed at least two-fold higher in myeloid compared to B-lymphoid cell lines. In contrast, MTRNR2, EEF1A1, PTMA, HLA-DR, C6orf115, PBX3, ENPP4, SELL, and IL3Ra were expressed more than 2-fold higher in B-lymphoid compared to myeloid cell lines studied here. Conclusion: Thus, B-lymphoid leukaemia cell lines here exhibited active, proliferating characteristics closer to GP genes. Higher expression of several genes in B-lymphoid compared to myeloid leukaemia cell lines may be useful markers to study biological differences including drug resistance between lineages.

Basic Fibroblast Growth Factor Enhances the Expansion and Secretory Profile of Human Placenta-Derived Mesenchymal Stem Cells

Introduction:Mesenchymal stem cells (MSCs) hold a great therapeutic potential for regenerative medicine and tissue engineering due to inherent immunomodulatory and reparative properties. Hence, it necessitates a readily available supplyof MSCs to meet the clinical demands adequately. Although, a human placenta can produce MSCs, the in vitro culture-mediated cellular senescence often affect the quality of cell product. Thus, the current study has explored the feasibility of basic fibroblast growth factor (bFGF) to enhance the growth of placenta-derived MSCs (PLC-MSCs). Methods:The basic fibroblast growth factor (bFGF) was supplemented to optimise the growth of MSCs. The effects of bFGF on morphology, growth kinetics and cytokine secretion of PLC-MSCs were assessed. Results: The bFGF supplementation increased the proliferation of PLC-MSCs in a dose-dependent manner and 40 ng/ml showed a high trophism effect on PLC-MSC’s growth. In the presence of bFGF, PLC-MSCs acquired a small and well-defined morphology that reflect an active proliferative status. BFGF has induced PLC-MSCs to achieve a shorter doubling time (45 hrs) as compared to the non-supplemented PLC-MSCs culture (81 hrs). Furthermore, bFGF impelled PLC-MSCs into cell cycle machinery where a substantial fraction of cells was driven to S and G2/M phases. Amongst, 36 screened cytokines, bFGF had only altered the secretion of IL-8, IL-6, TNFR1, MMP3 and VEGF. Conclusion:The present study showed that bFGF supplementation promotes the growth of PLC-MSCs without significantly deviating from the standard criteria of MSCs. Thus, bFGF could be considered as a potential mitogen to facilitate the large-scale production of PLC-MSCs.

Office Exercise Training to Reduce and Prevent the Occurrence of Musculoskeletal Disorders among Office Workers: A Hypothesis

Pain in specific areas of the body (including the lower back, neck, and shoulders) due to extended periods of sitting and inactivity is the most widespread musculoskeletal disorder worldwide and has consequences that are both socio-economic and personal. This condition is particularly prevalent in industrialised countries, affecting roughly 70% to 80% of adults at some point in their lives; approximately 1% of the U.S. population is chronically disabled by this type of pain disorder. A practical way to reduce the prevalence of musculoskeletal pain among office workers would have a significant positive impact. More work is required to develop a package of exercises designed to prevent and treat musculoskeletal pain in office workers. Such a package would be preferable to pharmacological treatments, which can have undesirable side effects. The main objective of this package would be to increase the flexibility and strength of trunk muscles in order to decrease the soreness, pain, and degree of discomfort. In this article, we introduce our proposed package of exercises, which are based on guidelines issued bythe American College of Sports Medicine.

Generation and characterisation of human umbilical cord derived mesenchymal stem cells by explant method

Mesenchymal stem cells (MSCs) derived from human umbilical cord (UC) have been considered as an important tool for treating various malignancies, tissue repair and organ regeneration. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) are better alternative to MSCs that derived from bone marrow (BM-MSCs) as they are regarded as medical waste with little ethical concern for research and easily culture-expanded. In this present study, the foetal distal end of human UC was utilised to generate MSC by explant method. Upon in vitro culture, adherent cells with fibroblastic morphology were generated with rapid growth kinetics. Under the respective inductive conditions, these cells were capable of differentiating into adipocytes and osteocytes; express an array of standard MSC’s surface markers CD29, CD73, CD90, CD106 and MHC-class I. Further assessment of immunosuppression activity revealed that MSCs generated from UC had profoundly inhibited the proliferation of mitogen-activated T lymphocytes in a dosedependent manner. The current laboratory findings have reinforced the application of explant method to generate UCMSCs thus, exploring an ideal platform to fulfil the increasing demand of MSCs for research and potential clinical use.

The Efficiency of Cell Sorting and Harvesting Methods for In vitro Expansion of Human Umbilical Cord Blood derived CD34+ Hematopoietic Stem Cells

Introduction: During the last three decades hematopoietic stem cell transplantation (HSCT) has become a well-established treatment for many hematologic malignancies. The most important limitation for HSC transplantation is the low number of hematopoietic stem cells (HSC) that can lead to delayed engraftment or graft failures. Numerous attempts have been made to improve in vitro HSC expansion via optimization of various methods such as isolation techniques, supplementing with growth factors, utilizing stromal cells as feeder layer and other culture conditions. Objective: This project is aimed to decipher the efficiency of an isolation technique and retrieval of culture expanded HSC from feeder layer using two different harvesting methods. Materials and Methods: Hematopoietic stem cells from human umbilical cord blood were isolated via MACS mediated CD34+ double sorting. Then, the cells were cultured onto MSC feeder layer for 3 and 5 days. Culture expanded cells were harvested using two different harvesting method namely cell aspiration and trypsinization methods. Hematopoietic stem cell expansion index were calculated based on harvesting methods for each time point. Results: The numbers of HSC isolated from human umbilical cord blood were 1.64 x 106 and 1.20 x106 cells at single and double sortings respectively. Although the number of sorted cells diminished at the second sorting yet the yield of CD34+ purity has increased from 43.73% at single sorting to 81.40% at double sorting. Employing the trypsinization method, the HSC harvested from feeder layer showed a significant increase in expansion index (EI) as compared to the cell aspiration harvesting method (p≤ 0.05). However, the purity of CD34+ HSC was found higher when the cells were harvested using aspiration method (82.43%) as compared to the trypsinization method (74.13%). Conclusion: A pure population of CD34+ HSC can be retrieved when the cells were double sorted using MACS and expanded in culture after being harvested using cell aspiration method.

Qualitative Flow Cytometric Analysis of Malaysian Myelodysplastic Syndromes (MDS) Patients

Myelodysplastic syndromes (MDS) are a group of haematological malignancies categorized by ineffective hematopoiesis that result in dysplasia. Although morphological diagnosis is a traditional and standard technique that is used for the diagnosis of MDS, the heterogeneous blood and bone marrow characteristics of MDS patients can potentially obscure the right diagnosis. Thus, we have utilized flow cytometric immunophenotyping as a supportive mechanism to obtain a more accurate and faster method for detection of abnormal markers in MDS. Flow cytometry was used for analyzing bone marrow samples from newly diagnosed MDS patients to investigate the abnormal antigen expression patterns in granulocytic, monocytic, erythroid, lymphoid lineages and myeloid precursors. The results were compared with those obtained from cases that had Idiopathic Thrombocytopenic Purpura (ITP) as a control. The most common abnormality found in the granulocytic lineage was the decrease of CD10. Low expressions of CD13 were the most frequent abnormality in the monocytic lineage. The erythroid lineage was found to have low expression of CD235A+/CD71+, reduce of CD71and decreased CD235a. In conclusion, this method is useful for confirming cases in which it is difficult to make a diagnosis by morphology.

Screening for Intermediate and Severe Forms of Thalassaemia in Discarded Red Blood Cells: Optimization and Feasibility

Detection and quantification of Hb subtypes of human blood is integral to presumptive identification of thalassaemias. It has been used in neonatal screening of thalassaemia and Hb variants. The use of discarded red blood cells following processing of the cord blood for stem cells provides readily available diagnostic material for thalassaemia screening. In this study, we determined the range of Hb subtypes in 195 consecutive cord blood samples collected for cord blood banking. The `cord blood samples’ analysed were those of the remaining red blood cells after the cord blood was processed for stem cell storage. Quantification of Hb subtypes by high performance liquid chromatography (HPLC) was done on BioRad Variant II Hb testing system. Only 73 (36.5%) of the samples could be analyzed neat without dilution. With a 1:300 dilution with wash solution the acceptable area as recommended by the manufacturer for reading of a C-gram within the 1 to 3 million ranges were achieved in all. Eighteen (9%) 12 showed classical Hb Barts (γ4) prerun peaks were confirmed by Sebia Hydrasys automated Hb gel electrophoresis and quantified by Sebia Capillarys 2 capillary electrophoresis. Only 1 (0.5%) was presumptively identified with HbH disease. Due to the limited number of samples no beta-thalassaemia major, Hb E beta-thalassaemia and Hb Barts hydrops fetalis were found. The HPLC assay was possible at a cost US$ 5 per sample and a turnover time of 10 samples per hour without technical difficulties. This study reports an effective and valuable protocol for thalassaemia screening in red blood cells which would otherwise be discarded during cord blood processing. Cord blood with severe and intermediate forms of thalassaemia can be preselected and not stored.

Establishing a Culture System that Supports in Vitro Expansion of Adult Microglia

Introduction: The vast majority of in vitro research on microglia are based on cells isolated from neonatal animals (3-5 days of age). Studying microglia of adults has been limited by the lack of a suitable culture system that supports their growth. In this study, we describe a protocol for growing microglia of adults based on modifications of the technique for culturing microglia isolated from neonatal rats. Methods: Mixed glia isolated from adult rats (age range of 1 month to 3 years old) were seeded in culture flasks coated with poly-L-lysine. Cells were maintained in DMEM media supplemented with insulin-transferrin-selenium (ITS) and recombinant human macrophage colony-stimulating factor (M-CSF). Mild trypsinisation was carried out to isolate microglia from mixed glia culture. Results: Microglia cells of adult rats were successfully grown in vitro. For the expansion of adult microglia, it was observed that coating the cell culture flasks with poly-L-lysine was crucial to encourage cell adherence. The substitution of insulin in culture media with ITS was found to improve cell yield and reduced the number of days required for culture from 28 days to 14 days. Addition of M-CSF to cell culture medium, along with the improvisations described above provided the best adult microglia cell yield (2.91 ± 0.56 x 10⁶ cells) compared to the technique of replating cells (0.91 ± 0.65 x 10⁶ cells; p<0.05). Conclusion: Optimisation of primary cell culture technique by coating culture flasks with poly-L-lysine,supplementation of culture medium with ITS and M-CSF allowed microglia of adult rats to be successfully cultured in vitro