The main aim of the present study was to evaluate the capacity of stem cells from human exfoliated deciduous teeth (SHED) to enhance mandibular distraction osteogenesis (DO) in rabbits.
Immune Thrombocytopenia Purpura (ITP) secondary to vaccinations is rare, especially after autologous hematopoietic stem cell transplantation (HSCT). A 31-yearold female received autologous HSCT for relapsed Hodgkin Disease, with platelet engraftment at Day+14. One week after receiving second scheduled vaccinations, she developed severe thrombocytopenia (3x109/L) associated with pharyngeal hematoma. Bone marrow (BM) examinations were consistent with ITP, possibly secondary to Influenza vaccine. Platelet increment was poor despite high dose corticosteroids, intravenous immunoglobulin (IVIG), Danazol and Eltrombopag. A repeated BM biopsy was in agreement with ITP. Re-treatment with tapering doses of prednisolone resulted in stable platelet counts at 120x109/L a year later.
Autologous nerve grafts to bridge nerve gaps have donor site morbidity and possible neuroma formation resulting in development of various methods of bridging nerve gaps without using autologous nerve grafts. We have fabricated an acellular muscle stuffed vein seeded with differentiated mesenchymal stem cells (MSCs) as a substitute for nerve autografts. Human vein and muscle were both decellularized by liquid nitrogen immersion with subsequent hydrolysis in hydrochloric acid. Human MSCs were subjected to a series of treatments with a reducing agent, retinoic acid, and a combination of trophic factors. The differentiated MSCs were seeded on the surface of acellular muscle tissue and then stuffed into the vein. Our study showed that 35-75% of the cells expressed neural markers such as S100b, glial fibrillary acidic protein (GFAP), p75 NGF receptor, and Nestin after differentiation. Histological and ultra structural analyses of muscle stuffed veins showed attachment of cells onto the surface of the acellular muscle and penetration of the cells into the hydrolyzed fraction of muscle fibers. We implanted these muscle stuffed veins into athymic mice and at 8 weeks post-implantation, the acellular muscle tissue had fully degraded and replaced with new matrix produced by the seeded cells. The vein was still intact and no inflammatory reactions were observed proving the biocompatibility and biodegradability of the conduit. In conclusion, we have successfully formed a stable living nerve conduit which may serve as a substitute for autologous nerves.
Tapping into the ability of engineered mesenchymal stem cells (MSCs) to mobilise into the tumour has expanded the scope of cancer treatment. Engineered MSCs expressing tumour necrosis factor (TNF)-related apoptosis inducing ligand (MSC-TRAIL) could serve as a platform for an efficient and targeted form of therapy. However, the presence of cancer stem cells (CSCs) that are resistant to TRAIL and apoptosis may represent a challenge for effective treatment. Nonetheless, with the discovery of small molecular inhibitors that could target CSCs and tumour signalling pathways, a higher efficacy of MSC-TRAIL mediated tumour inhibition can be achieved. This might pave the way for a more effective form of combined therapy, which leads to a better treatment outcome. In this review, we first discuss the tumour-homing capacity of MSCs, its effect in tumour tropism, the different approach behind genetically-engineered MSCs, and the efficacy and safety of each agent delivered by these MSCs. Then, we focus on how sensitisation of CSCs and tumours using small molecular inhibitors can increase the effect of these cells to either TRAIL or MSC-TRAIL mediated inhibition. In the conclusion, we address a few questions and safety concerns regarding the utilization of engineered MSCs for future treatment in patients.
The dynamic nature of modern warfare, including threats and injuries faced by soldiers, necessitates the development of countermeasures that address a wide variety of injuries. Tissue engineering has emerged as a field with the potential to provide contemporary solutions. In this review, discussions focus on the applications of stem cells in tissue engineering to address health risks frequently faced by combatants at war. Human development depends intimately on stem cells, the mysterious precursor to every kind of cell in the body that, with proper instruction, can grow and differentiate into any new tissue or organ. Recent reports have suggested the greater therapeutic effects of the anti-inflammatory, trophic, paracrine and immune-modulatory functions associated with these cells, which induce them to restore normal healing and tissue regeneration by modulating immune reactions, regulating inflammation, and suppressing fibrosis. Therefore, the use of stem cells holds significant promise for the treatment of many battlefield injuries and their complications. These applications include the treatment of injuries to the skin, sensory organs, nervous system tissues, the musculoskeletal system, circulatory/pulmonary tissues and genitals/testicles and of acute radiation syndrome and the development of novel biosensors. The new research developments in these areas suggest that solutions are being developed to reduce critical consequences of wounds and exposures suffered in warfare. Current military applications of stem cell-based therapies are already saving the lives of soldiers who would have died in previous conflicts. Injuries that would have resulted in deaths previously now result in wounds today; similarly, today's permanent wounds may be reduced to tomorrow's bad memories with further advances in stem cell-based therapies.
In neurodegenerative diseases, such as Alzheimer's and Parkinson's, microglial cell activation is thought to contribute to their degeneration by producing neurotoxic compounds. While dental pulp stem cells (DPSCs) have been regarded as the next possible cell source for cell replacement therapy (CRT), their actual role when exposed in such harsh environment remains elusive. In this study, the immunomodulatory behavior of DPSCs from human subjects was investigated in a coculture system consisting of neuron and microglia which were treated with 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine, which mimics the inflammatory conditions and contribute to degeneration of dopaminergic (DA-ergic) neurons. Assessments were performed on their proliferation, extent of DNA damage, productions of reactive oxygen species (ROS) and nitric oxide (NO), as well as secretion of inflammatory mediators. Notably, DPSCs were shown to attenuate their proliferation, production of ROS, and NO significantly (P
Numerous lines of evidence support that bone marrow is a rich source of stem cells that can be used for research purposes and to treat some complex blood diseases and cancers. Stem cells are a potential source for regenerative medicine and tissue replacement after injury or disease, and mother cells that possess the capacity to become any type of cell in the body. They are cells without specific structure and characterized by their ability to self-renew or multiply while maintaining the potential to develop into other types of cells. Stem cells can normally become cells of the blood, heart, bones, skin, muscles or brain. Although, there are different sources of stem cells, all types of stem cells have the same capacity to develop into multiple types of cells. Stem cells are generally described as unspecialized cells with unlimited proliferation capacity that can divide (through mitosis) to produce more stem cells. Several types of adult stem cells have been characterized and can be cultured in vitro, including neural stem cells, hematopoietic stem cells, mesenchymal stem cells, cardiac stem cells and epithelial stem cells. They are valuable as research tools and might, in the future, be used to treat a wide range of diseases such as hematological hereditary diseases, Parkinson's disease, diabetes mellitus, heart disease and many other diseases. Currently, two types of stem cells have been identified based on their origins, namely embryonic stem cells and adult stem cells. Collectively, although many kinds of literature have been studying stem cell application in terms of clinical practice, stem cell-based therapy is still in its infancy stage.
Mesenchymal stromal cells (MSC) are an attractive cell-targeting vehicle for gene delivery. MIDGE (an acronym for Minimalistic, Immunologically Defined Gene Expression) construct is relatively safer than the viral or plasmid expression system as the detrimental eukaryotic and prokaryotic gene and sequences have been eliminated. The objective of this study was to test the ability of the human MSC (hMSC) to deliver the erythropoietin (EPO) gene in a nude mice model following nucleofection using a MIDGE construct. hMSC nucleofected with MIDGE encoding the EPO gene was injected subcutaneously in Matrigel at the dorsal flank of nude mice. Subcutaneous implantation of nucleofected hMSC resulted in increased hemoglobin level with presence of human EPO in the peripheral blood of the injected nude mice in the first two weeks post-implantation compared with the control groups. The basal layer of the hair shaft in the dermal layer was found to be significantly positive for immunohistochemical staining of a human EPO antibody. However, only a few basal layers of the hair shaft were found to be positively stained for CD105. In conclusion, hMSC harboring MIDGE-EPO could deliver and transiently express the EPO gene in the nude mice model. These cells could be localized to the hair follicle and secreted EPO protein might have possible role in hair regeneration.
Graft-versus-host Disease (GVHD) is the main cause of morbidity and mortality after allogeneic hematopoietic
stem cell transplantation (alloHSCT). In spite of immune-suppressive prophylaxis, most survivors suffer from
acute and chronic GVHD (aGVHD and cGVHD). The outcome of alloHSCT may be affected by the presence of
single nucleotide polymorphism (SNP) in non-HLA genes including those involved in innate immune responses.
This study aimed to evaluate the impact of cytotoxic T-lymphocyte antigen-4 (CTLA-4) and caspase recruitment
domain 15 (NOD2/CARD15) gene polymorphisms on the incidence and severity of aGVHD and cGVHD following
alloHSCT. A structured literature review was carried out using various keywords and MESH terms such as
stem cell transplantation, allogenic haematopoietic stem cell transplantation, GVHD, and non-HLA gene
polymorphism, in PubMed, Google Scholar and Cochrane Database. A total of 8 studies that met inclusion
criteria (English publications from 2006 to 2017) were included. Ten SNPs in CTLA-4 gene and three SNPs in
NOD2/CARD15 gene were tested in patients with underlying haematological malignancies. Four studies tested
the SNPs of CTLA-4 gene and two were found to have an association with CTLA-4 SNPs (rs3087243, rs231775)
and increased incidence of aGVHD. The other four studies tested the SNPs of NOD2/CARD15 gene and one
found an association between SNP13 and increased incidence of aGVHD. None of these eight studies found
any effect on severity of GVHD. In conclusion, two SNPs in CTLA-4 and one SNP in NOD2/CARD15 increased
the incidence of aGVHD but not its severity. The higher incidence of aGVHD in studies with larger sample size
could support the impact of SNPs in the outcome of alloHSCT. However, due to the heterogeneity of studies in
regard to the age of patients and donor, and conditioning regimen, it is difficult to draw a definite conclusion.
Allogeneic hematopoietic stem cell transplantation (HSCT) remains a potential curative option for many patients with hematological malignancies (HM). However, the high rate of transplantation-related mortality (TRM) restricted the use of standard myeloablative HSCT to a minority of young and fit patients. Over the past few years, it has become evident that the alloreactivity of the immunocompetent donor cells mediated anti-malignancy effects independent of the action of high dose chemoradiotherapy. The use of reduced intensity conditioning (RIC) regimens has allowed a graft-versus-malignancy (GvM) effect to be exploited in patients who were previously ineligible for HSCT on the grounds of age and comorbidity. Retrospective analysis showed that RIC has been associated with lower TRM but a higher relapse rate leading to similar intermediate term overall and progression-free survivals when compared to standard myeloablative HSCT. However, the long term antitumor effect of this approach is less well established. Prospective studies are ongoing to define which patients might most benefit from reduced toxicity stem cell transplant (RT-SCT) and which transplant protocols are suitable for the different types of HM. The advent of RT-SCT permits the delivery of a potentially curative GvM effect to the majority of patients with HM whose outcome with conventional chemotherapy would be dismal. Remaining challenges include development of effective strategies to reduce relapse rates by augmenting GvM effects without increasing toxicity.
Analysis of variable number tandem repeats (VNTRs) by polymerase chain reaction (PCR) is a common method used to predict engraftment status in post-allogeneic haematopoeitic stem cell transplantation (HSCT) patients. Different populations have different copies of repeated DNA sequence and hence, different percentage of informativeness between patient and donor.
Following hematopoietic stem cell transplantation (HSCT), it is important to determine whether engraftment is successful and to track the dynamic changes of the graft. Tandem repeats such as minisatellites and microsatellites are currently the most established markers for chimerism application. We have developed a reliable method to quantitatively evaluate engraftment status in post-allogeneic HSCT patients using variable number of tandem repeat (VNTR) markers and "lab-on-a-chip" microfluidic electrophoresis technology. Following identification of an informative marker by conventional polymerase chain reaction (PCR), donor chimerism percentage was calculated based on a standard curve generated from artificially mixed patient-donor DNA-specific alleles in serial dilutions. All PCR products were mixed with commercial gel dye and loaded into Agilent DNA 1000 microfluidic LabChips for DNA sizing and quantitation. In 44 patients, separation of pretransplant and donor DNA fragments was resolved clearly and accomplished rapidly within 30min. Chimerism analysis using this platform is able to detect an amount as low as 6.3% donor DNA with acceptable coefficient of variation values. We also demonstrated concordant chimerism analysis findings using both microchip tandem repeats and real-time PCR quantitation of insertion-deletion polymorphisms. This microchip platform obviates the need for fluorescently labeled primers or any post-PCR sample manipulation. Quantitative monitoring of post-HSCT chimerism status using microfluidic electrophoresis is a useful tool for both large- and small-scale post-HSCT chimerism centers.
The current treatment options for beta thalassaemia major patients include conservative treatment with blood cell transfusions and iron chelation or stem cell transplantation. Regular blood transfusions inevitably lead to multi-organ haemosiderosis and are attended by risks of blood-borne infections. Results from stem cell transplantation are good and suggest that this should be offered as first line therapy when a matched sibling donor is available because the patient is often cured and able to live a normal life. Of 38 Malaysian children who underwent bone marrow or cord blood transplantations using matched sibling donors, 29 (76%) are now cured.
Umbilical Cord Blood Transplant (UCBT) is a type of allogenic haematopoetic stem cell transplant. Stem cell transplantation as a mode of treatment of diseases was first successfully done by the pioneering work of a Nobel Prize Winner in Physiology or Medicine, E. Donnall Thomas in 1957. Throughout the past 50 years, numerous other researchers have improved the techniques of this previously highly risky procedure. Among the notable landmark in haematopoetic stem cell transplant include: advancement in immunogenetics of HLA, better immunosuppressive preparative regimen, improved control of infections, appearance of donor registries throughout the world and successful transplantation stories using haematopoetic stem cells from peripheral blood and the cord blood. These developments lead to a change in terminology from marrow transplantation to haematopoetic stem cell transplantation .
Studies of survival outcomes in acute myeloid leukemia (AML) patients treated with allogeneic haematopoietic stem cell transplantation (HSCT) are essential for planning patient care. The objectives of the present study were to determine overall survival (OS) and disease-free survival (DFS) in AML patients treated with allogeneic HSCT, and to identify prognostic factors associated with poor outcome. This study was conducted retrospectively, using data from the Blood and Bone Marrow Transplant, National Transplant Registry, Malaysia. All cases of AML treated with allogeneic HSCT registered at the registry between 1st January 1987 and 31st December 2010 were included in the study. A total of 300 patients were included for final analysis. The Kaplan-Meier method and Cox proportional hazard regression were used for statistical analysis. The overall 10-year OS and DFS for Malaysian AML patients after allogeneic HSCT were 63 and 67 %, respectively. Donor gender, marrow status, and conditioning intensity were identified as important prognostic factors for overall survival, whereas the significant prognostic factors for disease-free survival were ethnic group, donor gender, marrow status, and conditioning intensity. In conclusion, the survival outcomes for Malaysian AML patients treated with allogeneic HSCT were good, and this treatment should be considered the standard therapeutic approach for suitable candidates.
One of the major problems in the treatment of cardiovascular diseases is the inability of myocardium to self-regenerate. Current therapies are unable to restore the heart's function after myocardial infarction. Myocardial tissue engineering is potentially a key approach to regenerate damaged heart muscle. Myocardial patches are applied surgically, whereas injectable hydrogels provide effective minimally invasive approaches to recover functional myocardium. These hydrogels are easily administered and can be either cell free or loaded with bioactive agents and/or cardiac stem cells, which may apply paracrine effects. The aim of this review is to investigate the advantages and disadvantages of injectable stem cell-laden hydrogels and highlight their potential applications for myocardium repair.
The staggering number of publications featuring the use of stem cells has revolutionized regenerative medicine research. Preclinical studies indicate that allogeneic human mesenchymal stem cells (MSCs) may be useful for the treatment of several clinical disorders, including sepsis, acute renal failure, acute myocardial infarction, and more recently, acute lung injury (ALI). However, considerable success would not be obtained in clinical trials due to poor survival of transplanted cells under the influence of inflammatory conditions. Despite robust approaches like cellular reprogramming, scaffolds and conditioned media have been tested to overcome this problem; however the success rate of these approaches remain questionable. Recently, pretreatment of bioactive compounds in vitro have been shown to suppress cell apoptosis and promote cell survival. Quite likely a similar phenomenon can take place in vivo. Based on such studies, we hypothesize that MSCs derived from human post-natal tissues could be conditioned and prepared for targeted disease therapy. Depending on the disease condition, the MSCs could be treated prior to delivery with appropriate bioactive compounds to allow them survive longer and perform a better role as biocatalyst. The advantage of this approach could be the tailor made availability of MSCs preconditioned with appropriate bioactive compounds for disease specific therapy. Therefore, the choice of suitable bioactive molecule is likely to enhance the efficacy of targeted stem cell therapy and preconditioning may provide a novel strategy in maximizing biological and functional properties of MSCs.
We present a case of abdominal gastric band-associated Mycobacterium abscessus infection, manifesting after the onset of acute myeloid leukemia, complicated by immune reconstitution inflammatory syndrome (IRIS), and cured while receiving an allogeneic hematopoietic stem cell transplant. IRIS should be considered in less classical situations where there is unexplained clinical deterioration.
A 21-year-old lady diagnosed with Stage 3 ovarian yolk sac tumor (YST) underwent primary cytoreductive fertility sparing surgery, followed by conventional courses of platinum-based chemotherapy and etoposide. Recurrence at cul-da-sac was noted after a short period of remission and secondary debulking performed followed by four cycles of conventional chemotherapy. The patient's disease progressed despite courses of treatments. A joint team management including a hematologist was commenced following the failure of conventional chemotherapies. Two cycles of high-dose chemotherapy (HDCT) with ifosfamide/cisplatin/etoposide (ICE) regimen, followed by autologous stem cell transplantation (ASCT) were given. With this salvage treatment, she remained in complete remission and disease-free for more than 30 months, while maintaining her reproductive function. These approaches appear to be effective as a salvage treatment in selected cases of patients with ovarian germ cell tumor, especially those who failed primary conventional chemotherapy.