American journal of stem cells最新文献

Introduction: One of the most common orthodontic problems is maxillary constriction, which is mostly treated by rapid palatal expansion (RPE). However, its high rate of relapse and prolonged retention period have led to some challenges for orthodontists. To encounter these issues, accelerating bone regeneration can provide long-term stability of expanded maxilla. The present study aimed to evaluate the effect of low-level laser therapy (LLLT), bone marrow-derived mesenchymal stem cells (BMSCs) and their combination on promoting bone regeneration of the inter-maxillary suture after RPE in rats.

Materials and method: Total of 60 rats went under RPE treatment. After 7 days, retention period started and interventions (group A, Control (saline); group B, LLLT; group C, BMSCs; group D, LLLT + BMSCs) were performed in the sutural area. After 21 days, radiographic and histological analyses were done. Histological analyses were conducted to evaluate the following criteria of the newly formed bone: the number of osteoblasts, new bone formation, vascularization, connective tissue. Moreover, sutural width was assessed in histologic images. To evaluate bone density at suture area, gray scale and Hounsfield Unit values were measured based on the occlusal radiographic and Micro-Computed topography images respectively.

Results: Only in group C and D, osteoblasts and new bone formation were observed in all of the samples. There were no significant differences among the study groups regarding the post-treatment sutural width (P > 0.05). In the radiographic analysis, only group D showed more bone density compared to the control group (P = 0.022). Similarly, in micro-CT analysis, the most bone density was observed in group D which was significantly more than the control group (P = 0.013).

Conclusion: Our findings suggest that the application of LLLT and BMSCs is the most beneficial approach in accelerating bone regeneration in the inter-maxillary suture.

Two of the leading strategies to prevent cervical cancer are prophylactic human papillomavirus (HPV) vaccination and routine Papanicolaou (Pap) testing. However, regardless of being vaccinated with first-generation (bivalent and quadrivalent) HPV vaccines at the recommended dosing schedule, many women are still found to have low- and high-grade cervical intraepithelial lesions. Studies have shown that this is largely due to: (1) first-generation vaccines only protecting against 70% of high-risk HPV types that cause cervical cancer (HPVs 16/18) and (2) vaccinated women being more prone to infection with non-protected high-risk HPV types than unvaccinated women. Fortunately, the FDA recently approved a nonavalent vaccine that protects against 5 additional high-risk HPV types that cause 20% of cervical cancers (HPVs 31/33/45/52/58), which is the only HPV vaccine currently available in the United States. Although the Advisory Committee on Immunization Practices (ACIP) recommends the nonavalent vaccine in men and women up to the age of 45 years, it does not recommend the nonavalent vaccine in those previously vaccinated with 3 doses of bivalent or quadrivalent vaccine, deeming them "adequately vaccinated". As this population is most at risk, this review serves to provide background and argue for a change in their recommendation.

End-stage liver disease is a worldwide cause of morbidity and mortality, which is associated with a considerable economic burden. As the disease progresses, fibrosis will replace the hepatic architecture and compromise liver functions. The regenerative approach for the injured liver can provide a hope for these patients; however, it is still facing many challenges. In the current study, we aimed at (1) assessing hepatic regenerative capacity of mesenchymal stem cells, isolated from human umbilical cord blood (HMSCs), in a rat model of carbon-tetrachloride (CCL4) induced liver fibrosis, (2) comparing the therapeutic effects with other cell populations derived from umbilical cord blood and (3) evaluating the host response to the human-derived cells. Fifteen rats received either the whole mononuclear cell fraction (HMNCs), CD34-ve subpopulation or HMSCs. A fourth group did not receive any treatment and another group was left without induction of fibrosis as positive and negative controls. All groups that received cellular treatment showed homing of the human cells and improvement of the liver architecture and functional capacity. The groups received CD34-ve cells and HMSCs had the most efficient improvement in liver functions, microscopic regenerative markers and histological appearance while the least immune reaction was noted with HMSCs. HUCB-MSCs showed significant immunemodulatory effect on rat immune cells. This study can provide a clue about a simple and effective method for the management of fibrotic liver diseases.

Cerebellar granule cells originate from precursors located at the dorsal region of rhombomere in the hindbrain of embryos. They undergo proliferation from embryo to post-natal period so as to form the major cell type of the cerebellum. The development of granule cell is not only highly dependent on the cerebellar intrinsic environment, but also is regulated by serials of transcription factors on different signaling pathways. Therefore, in this manuscript the signaling pathways participating in the proliferation and differentiation of granular cells during normal development was reviewed.

The objective of this study was to evaluate the influence of mesenchymal stem cells on the healing of experimental carotid artery anastomoses histopathologically. Twenty-four female Sprague-Dawley rats were used in this study. After random separation of the subjects into two groups, in both groups carotid arteries were transected and anastomosed in end-to-end fashion. Anastomoses were locally treated with 1 ml 0.09% NaCl, and 1 ml mesenchymal stem cell suspension (1×10⁶ cells) in control and trial groups, respectively. Anastomoses were wrapped with an 8 mm sheet of surgicel and soaked with BioGlue in order to sequestrate the stem cells. After patencies were confirmed via Doppler USG, surgical site was closed with 2/0 silk sutures. Histopathological evaluation was carried out after 4 weeks. In respect to endothelial continuity, vessel patency (along with presence or absence of restenosis), integrities of internal and external elastic laminae, muscularis and adventitia; no statistically significant differences were present between the trial and control groups. In Trial and Control Groups, luminal thrombus was present in 8 (66.6%) and 3 (25%) of the 12 subjects, respectively. The difference was statistically significant (P < 0.05). Recanalization was present in 6 subjects in trial group; 1 subjects in Control Group, respectively. Our results suggest that local administration of mesenchyme stem cell does not have a positive influence on success of an anastomosis.

Type 1 diabetes mellitus (T1DM) is an autoimmune disorder in which the body destroys its pancreatic β cells. Since these cells are responsible for insulin production, dysfunction or destruction of these cells necessitates blood glucose control through exogenous insulin shots. Curative treatment involves pancreas transplantation, but due to the incidence of transplant rejection and complications associated with immunosuppression, alternatives are being explored. Despite facing clinical challenges and issues with public perception, the field of regenerative stem cell therapy shows great promise for the treatment of diabetes. The idea of harnessing pluripotency to derive cells and tissues with characteristics of choice is astounding but feasible, and this review seeks to determine which method of stem cell derivation is preferable for diabetes treatment. In this report, we outline the methods for deriving human embryonic stem cells (hESCs), induced pluripotent stem cells (iPSCs), and adult stem cells or progenitor cells to generate functional islet cells and related tissues. We discuss the specific uses and advantages of each method, and we comment on the ethics and public perceptions surrounding these methods and how they may affect the future of stem cell research. For the reasons outlined in this paper, we believe that non-embryonic stem cell lines, including iPSCs, somatic cell nuclear transfer lines, and adult tissue derived stem cells, offer the highest therapeutic potential for treating diabetes.

In recent years, the therapeutic use of mesenchymal stromal cells (MSC) has generated a valuable number of scientific studies that delve into their biological characteristics and their potential in regenerative medicine; however, the impact of the clinical characteristics of tissue donors, from which these cells are isolated, on their potential in applied clinical research is not yet clear. The objective of this study was to evaluate the impact of the clinical characteristics of bone marrow donors on the quality of this tissue as a source of MSC for therapeutic use. Human MSC were isolated, characterized and cultured (according to ISCT criteria) from bone marrow samples from volunteer donors (n = 70) attending the Department of Orthopedics and Traumatology of the Hospital Universitario San Ignacio (Bogota, Colombia) for surgery of prosthetic hip replacement that agreed to participate voluntarily in the study. Donor data such as age, gender, weight, smoker and type of anesthesia used during the surgical procedure were recorded, and the impact of these characteristics on the volume of tissue collection, mononuclear cell count and confluence time of cells with fibroblastoid morphology was evaluated. Correlation coefficients between quantitative variables were calculated with Spearman's correlation test, and the association between qualitative and quantitative variables was evaluated with biserial correlation coefficient. A significant correlation was observed between the age of the donors and the time necessary to obtain confluent cells in vitro (r = 0.2489, P = 0.0377); similarly, the correlation between the volume of bone marrow collected and the number of mononuclear cells obtained was significant (r = 0.7101, P = 0.0001). Although a negative correlation tendency was observed between the mononuclear cell count and the confluence time, this was not significant (r = -0.2041, P = 0.0950). No significant associations were observed between gender, smoking status or type of anesthesia and the expansion characteristics of human mesenchymal stromal cells. Bone marrow donor age and the tissue collection volume impact the time of obtaining MSC in vitro and the mononuclear cell count with which the culture starts. These conditions must be considered when the bone marrow is selected as the tissue for obtaining MSC.

Type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) are widely prevalent metabolic diseases with differing pathologies. T1DM manifests due to autoimmune destruction of the pancreatic beta cells, resulting in a diminished secretion of insulin. T2DM originates from a state of insulin resistance, resulting in hyperglycemia and reduction in beta cell mass. Both diseases can cause severe health consequences. Despite the globally increasing prevalence of both T1DM and T2DM there remains to be a medically defined cure for either of these diseases. Recently, mesenchymal stem cells (MSCs) have been proposed as a possible curative treatment method. In this review, we explain the molecular mechanisms underlying MSCs and their potential ability to treat T1DM and T2DM. We describe the capability of MSCs to differentiate into insulin-producing cells and regenerate pancreatic beta cells, as well as assess their role in modulating the immune system. Lastly, we evaluate the current literature focusing on the clinical application of MSC transplantation in T1DM and T2DM. Despite the favorable results, study designs and analyses cast doubt on the effectiveness of MSCs for the management of T1DM. Conversely, the positive metabolic effects consistently demonstrated in the literature offer hope for MSCs as a treatment for T2DM, at least in the short-term.

Genetic imprinting is the process of epigenetic labelling or silencing of particular genes, based on the maternal or paternal origin of the gene, in a heritable pattern. The incidence of imprinting disorders has become a growing concern due to the potential association between these congenital syndromes and assisted reproductive technologies (ARTs). This review presents a general summary of the imprinting process as well as the current knowledge surrounding the genetic and epigenetic underpinnings of the most prevalent imprinting disorders: Beckwith-Wiedemann syndrome (BWS), Silver-Russell syndrome (SRS), Prader-Willi syndrome (PWS), and Angelman syndrome (AS). As research continues to elucidate the molecular pathways that characterize genetic imprinting, efforts have been made to establish guidelines that incorporate phenotypic manifestations as well as genetic testing to ensure safe and effective management of symptoms. While these efforts are likely to benefit future clinical management, their efficacy cannot yet be generalized to all patients diagnosed with these syndromes, as many of the genetic abnormalities and the associated phenotypic manifestations have yet to be characterized. Furthermore, future advances in the knowledge of epigenetic processes and genetic loci involved in the development of these syndromes may allow for the development of curative therapies.

Cardiovascular disease (CVD) is the number one cause of death globally, and new therapeutic techniques outside of traditional pharmaceutical and surgical interventions are currently being developed. At the forefront is stem cell-centered therapy, with adipose derived stem cells (ADSCs), an adult stem population, providing significant clinical promise. When introduced into damaged heart tissue, ADSCs promote cardiac regeneration by a variety of mechanisms including differentiation into new cardiomyocytes and secretion of paracrine factors acting on endogenous cardiac cells. We discuss the application of ADSCs, their biochemical capabilities, availability, ease of extraction, clinical trial results, and areas of concern. The multipotent capacity of ADSCs along with their ability to secrete factors promoting cell survival and regeneration, along with their immunosuppressive capacity, make them an extremely promising approach in the field of CVD therapy.