Islet organoid as a promising model for diabetes

Studies on diabetes have long been hampered by a lack of authentic disease models that, ideally, should be unlimited and able to recapitulate the abnormalities involved in the development, structure, and function of human pancreatic islets under pathological conditions. Stem cell-based islet organoids faithfully recapitulate islet development in vitro and provide large amounts of three-dimensional functional islet biomimetic materials with a morphological structure and cellular composition similar to those of native islets. Thus, islet organoids hold great promise for modeling islet development and function, deciphering the mechanisms underlying the onset of diabetes, providing an in vitro human organ model for infection of viruses such as SARS-CoV-2, and contributing to drug screening and autologous islet transplantation. However, the currently established islet organoids are generally immature compared with native islets, and further efforts should be made to improve the heterogeneity and functionality of islet organoids, making it an authentic and informative disease model for diabetes. Here, we review the advances and challenges in the generation of islet organoids, focusing on human pluripotent stem cell-derived islet organoids, and the potential applications of islet organoids as disease models and regenerative therapies for diabetes.

Adult Stem Cell Treatment for Rheumatoid Arthritis

Since methotrexate began to be used in the treatment of rheumatoid arthritis (RA) 30 years ago, RA treatments have advanced rapidly from only reducing joint pain and inflammation to suppressing disease progression and joint destruction. In particular, the development of biologics and targeted anti-rheumatic drugs has almost made it possible to induce remission in patients with RA. On the other hand, the current RA treatments are still limited by adverse effects and treatment failure. Stem cell therapy has been suggested as an alternative treatment of RA, and preclinical studies and clinical trials using representative adult stem cells (ASCs), hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs), are currently underway. HSC therapy in RA has mostly progressed based on the concept of ‘immune reset’, in which the existing immune cells are replaced with healthy ones. HSC transplantation was completed relatively safely, and the patients showed a positive treatment response. Nevertheless, the treatment response of HSCs in RA depends on the conditioning regimen, and the efficacy did not persist for a long time. The MSCs possessed a hypo-immunogenicity, immune modulation effect and tissue regeneration capability, making them another promising candidate for the RA treatment. MSC transplantation in RA was found to be safe with few adverse effects, such as immune rejection or embolism, but it showed a partial and transient response. This review addresses the characteristics of ASCs, focusing specifically on HSCs and MSCs, and summarizes the results of preclinical studies and clinical trials of ASC therapy in RA.

Adult Stem Cells of Orofacial Origin: Current Knowledge and Limitation and Future Trend in Regenerative Medicine

Stem cell research is one of the most rapidly expanding field of medicine which provides significant opportunities for therapeutic and regenerative applications. Different types of stem cells have been isolated investigating their accessibility, control of the differentiation pathway and additional immunomodulatory properties. Bulk of the literature focus has been on the study and potential applications of adult stem cells (ASC) because of their low immunogenicity and reduced ethical considerations. This review paper summarizes the basic available literature on different types of ASC with special focus on stem cells from dental and orofacial origin. ASC have been isolated from different sources, however, isolation of ASC from orofacial tissues has provided a novel promising alternative. These cells offer a great potential in the future of therapeutic and regenerative medicine because of their remarkable availability at low cost while allowing minimally invasive isolation procedures. Furthermore, their immunomodulatory and anti-inflammatory potential is of particular interest. However, there are conflicting reports in the literature regarding their particular biology and full clinical potentials. Sound knowledge and higher control over proliferation and differentiation mechanisms are prerequisites for clinical applications of these cells. Therefore, further standardized basic and translational studies are required to increase the reproducibility and reduce the controversies of studies, which in turn facilitate comparison of related literature and enhance further development in the field.

Genome engineering of stem cell organoids for disease modeling

Precision medicine emerges as a new approach that takes into account individual variability. Successful realization of precision medicine requires disease models that are able to incorporate personalized disease information and recapitulate disease development processes at the molecular, cellular and organ levels. With recent development in stem cell field, a variety of tissue organoids can be derived from patient specific pluripotent stem cells and adult stem cells. In combination with the state-of-the-art genome editing tools, organoids can be further engineered to mimic disease-relevant genetic and epigenetic status of a patient. This has therefore enabled a rapid expansion of sophisticated in vitro disease models, offering a unique system for fundamental and biomedical research as well as the development of personalized medicine. Here we summarize some of the latest advances and future perspectives in engineering stem cell organoids for human disease modeling.

MatrigelBD, a biocompatible scaffold that improves gingival mesenchymal stem cells proliferation / MatrigelBD, un andamiaje biocompatible que estimula la proliferación de celulas troncales mesenquimales derivadas del tejido gingival

MatrigelBD is a hydrogel scaffold with three-dimensional intercrossed networks of hydrophilic polymers with high water content. Human gingival tissue might represent a better source of MSCs, allowing these cells to be easily obtained in a relatively non-invasive way. The objective of this study was to evaluate the biocompatibility of MatrigelBD with GMSCs in vitro. Gingival connective tissue samples were obtained from healthy donors. Fresh tissue was minced and cultured during two weeks, after which cells at passage fourth were analyzed for their immune phenotype by flow cytometry. Differentiation into osteogenic, chondrogenic, and adipogenic lineages was induced and evaluated by culture staining. The "construct" was made of MatrigelBD with GMSC. To assess the biocompatibility, an MTT cellular proliferation assay was performed. The differentiation potential of the cells toward the osteogenic, adipogenic, and chondrogenic lineages was analyzed after 21 days of growth in MatrigelBD with induction differentiation media. The MTT analysis showed that MatrigelBD stimulated cell proliferation; the GMSCs maintained the expression of MSC markers. Importantly, the growth of GMSCs within the MatrigelBD did not interfere with the cell differentiation potential. These findings indicate that MatrigelBD is biocompatible with GMSCs, and this matrix improves cell proliferation in vitro.

MatrigelBD es un andamiaje de hidrogel con redes tridimensionales entrecruzadas de polímeros hidrófilos con un alto contenido de agua. El tejido gingival humano podría representar una mejor fuente de MSCs, estas células pueden obtenerse fácilmente de una manera relativamente no invasiva. El objetivo de este estudio fue evaluar la biocompatibilidad de MatrigelBD con GMSCs in vitro. Muestras gingivales de tejido conectivo se obtuvieron de donantes sanos. El tejido se trituró y se cultivó durante dos semanas, y cuando las células se encontraban en el cuarto pasaje se les analizó su fenotipo inmunológico utilizando citometría de flujo. Se indujo la diferenciación hacia los linajes osteogénico, condrogénico y adipogénico, evaluandose con tinciones. El "constructo" se hizo de MatrigelBD con GMSC. Para evaluar la biocompatibilidad, se realizó un ensayo de proliferación celular: MTT. Se analizó el potencial de diferenciación de las células hacia los linajes osteogénico, adipogénico y condrogénico después de 21 días de cultivo en MatrigelBD con medio de diferenciación de inducción. El análisis de MTT mostró que MatrigelBD estimula la proliferación celular; GMSCs mantiene la expresión de marcadores de MSC. Es importante destacar que el crecimiento de GMSCs en MatrigelBD no interfirió con el potencial de diferenciación celular. Estos hallazgos indican que MatrigelBD es biocompatible con GMSCs, y esta matriz mejora la proliferación celular in vitro.

Endogenous Stem Cells in the Ear / 대한이비인후과학회지

Basically stem cells have characteristics of multi-potency, differentiation into multiple tissue types, and self-renew through proliferation. Recent advances in stem cell biology can make identifying the stem-cell like cells in various mammalian tissues. Stem cells in various tissues can restore damaged tissue. Stem cells from the adult nervous system proliferate to form clonal floating colonies called spheres in vitro, and recent studies have demonstrated sphere formation by cells in the tympanic membrane, vestibular system, spiral ganglion, and partly in the organ of Corti. The presence of stem cells in the ear raises the possibilities for the regeneration of the tympanic membrane & inner ear hair cells & neurons. But the gradual loss of stem cells postnatally in the organ of Corti may correlate with the loss of regenerative capacity and limited hearing restoration. Future strategies using endogenous stem cells in the ear can be the another treatment modality for the patients with intractable inner ear diseases.

Isolation and cultivation of rat epidermal stem cells in basal layer * / 重庆医学

Objective To establish a simple and reliable method for isolation and cultivation of epidermal stem cells from neo-natal rat skin basal layer .Methods The single cells were dissociated with twice trypsinization form neonatal rat skin .Thereafter we purified the basal layer stem cells with differential velocity adherent technique with collagen Ⅳ ,and the slow adherent cells were cultured as negative control cells .Both basal layer stem cells and control cells were cultivated with keratinocyte serum-free medium (K-sfm) .Stem cells were identified with β1-integrin and Keratin 19 by co-immunofluorescence assay ,and colony forming assay was executed to evaluate the proliferation potential of stem cells .Results The polygonal cells grew like flagstones ,with doubling time of approximately 24 hours .Both the morphology and growth properties of cells were in accordance with the character of basal layer stem cells .Co-immunofluorescence identification showed the cells were positive for the expression of β1-integrin and Keratin 19 . Basal layer stem cells had stronger clone forming ability in vitro compare with control group .Conclusion The results indicate that two-procedure trypsinization plus differential velocity adhesion is an ideal method for basal layer stem cells separation followed with vigorous vitality and reliable phenotype .

Stem cells: sources and therapies

The historical, lexical and conceptual issues embedded in stem cell biology are reviewed from technical, ethical, philosophical, judicial, clinical, economic and biopolitical perspectives. The mechanisms assigning the simultaneous capacity to self-renew and to differentiate to stem cells (immortal template DNA and asymmetric division) are evaluated in the light of the niche hypothesis for the stemness state. The induction of cell pluripotency and the different stem cells sources are presented (embryonic, adult and cord blood). We highlight the embryonic and adult stem cell properties and possible therapies while we emphasize the particular scientific and social values of cord blood donation to set up cord blood banks. The current scientific and legal frameworks of cord blood banks are reviewed at an international level as well as allogenic, dedicated and autologous donations. The expectations and the challenges in relation to present-day targeted diseases like diabetes mellitus type I, Parkinson's disease and myocardial infarction are evaluated in the light of the cellular therapies for regenerative medicine.

Clinical effect of adult stem cell application in motor neuron disease in 20 cases / 中国综合临床

Objective To study the feasibility of adult stem cell therapy in motor neuron disease. Methods From May 2008 to March 2010, twenty patients with motor neuron disease were treated with adult stem cell. The patients were divided into two groups with umbilical cord mesenchymal stem cell in 14 cases (group A)and autologous Hematopoietic stem cell in 6 cases( group B). 4 ml stem cell ( ＞ 1.0 × 107) were given through subarachnoid injection. 1.0 × 107 cell were injected each time, and rehabilitation were performed simultaneously. Results Seven patients have improved in the dysphagia, bucking, continuity of language and thinking and reaction after 2 weeks' treatment. Seven patients improved remarkably in myodynamia( from Ⅲ to Ⅳ ). There was no effect observed in 6 patients. Three patients died during the follow up for 3 - 6 months. Three patients were followed up for 18 to 24 months and their condition did not getting worse. Conclusion Adult stem cell transplantation may be a safe and practical new ways to treat motor neuron disease.

Ex-pulmonary adult stem cell engraftment in treatment of acute lung injury: Recent progress / 第二军医大学学报

Engraftment with ex-pulmonary adult stem cells has great potential for treatment of acute lung injury (ALI). The engrafted adult ex-pulmonary stem cells can migrate to the injured lung tissue guided by a series of signal factors released by injured pulmonary tissue cells. Stem cells localized in the injured lung tissue and inflammatory area can differentiate into lung tissue cells (including lung epithelial cells and pulmonary vascular endothelial cells) and exert their functions. The engrafted expulmonary adult stem cells are not only capable of differentiation, but also have anti-inflammatory effect and immunomodulatory effect, making the related area a focus of study.

Role of autologous adult stem cells in liver firbrosis / 中华肝胆外科杂志

Hepatic fibrosis is a wound-healing re-sponse to all kinds of chronic liver injury, which if persistent can lead to cirrhosis. Once develops to cirrhosis, the only ef-fective therapy will be liver transplantation. In recent years,many scholars have taken all kinds of methods to try to pre-vent liver fibrosis developing to cirrhosis. As auto adult stem cell possesses multi-directional differentiation and none reject reaction advantages, it has become the study hotspot of nu-merous researches for hepatic fibrosis therapy and acquired significant progression.

The expression of survivin and its related genes in adipocyte-derived stem cell by demethylation / 대한마취과학회지

BACKGROUND: Survivin is thought to contribute to stem cell maintenance partly by a hypomethylation mechanism. This study attempted to elucidate the signal transduction pathway of adipocyte-derived stem cells (ASCs) by using a demethylating agent, 5-aza-2'-deoxycytidine (ADC), to analyze the survivin, MEK/ERK, c-Myc and p53 gene expression. METHODS: Demethylation in the ASCs was induced by 1 micrometer ADC treatment. RT-PCR for survivin mRNA was preformed, before and 24, 48 and 72 hours (hr) after ADC treatment. Western blotting analysis was performed for p53, survivin, unphosphorylated and phosphorylated (p)-MEK, and p-ERK. Immunohistochemistry for ERK and survivin was done to evaluate the localization of the proteins. RESULTS: ADC inhibited the population growth of the ASCs and it increased the number of apoptotic cells 24, 48, and 72 hr after treatment. ADC treatment slightly decreased the expression of survivin mRNA after 48 hr and its level was restored after 72 hr of treatment. Otherwise, the level of survivin protein gradually increased up to 48 hr and it was decreased at 72 hr. The levels of p-MEK and p53 were increased time-dependently. c-Myc and p-ERK were elevated after ADC treatment and their highest levels were seen 48 hr after treatment. The ADC treatment increased the nuclear expression of ERK and survivin in the ASCs. CONCLUSIONS: The overexpression of p-MEK/ERK, p53, and c-Myc increased the survivin protein expression of the demethylated ASCs. These results suggest that demethylation could alter the expression of survivin, and p53, c-Myc and the MAPK (MEK/ERK) pathway might play a role in survivin's regulation in ASCs.

Cross-talk between BubR1 expression and the commitment to differentiate in adipose-derived mesenchymal stem cells

BubR1 mitotic checkpoint kinase monitors attachment of microtubules to kinetochores and links regulation of the chromosome-spindle attachment to mitotic checkpoint signaling. Defects in BubR1-mediated signaling severely perturb checkpoint control and are linked to diseases such as cancer. Studies using BubR1 mouse models suggest that BubR1 activities prevent premature aging and infertility. In this study, we show that BubR1 depletion in human adipose-derived mesenchymal stem cells (ASCs) precedes loss of the differentiation potential and induction of replicative senescence. These effects occur independently of p16(INK4A) expression and may involve DNA methylation. Our results reveal a new and unsuspected feature of BubR1 expression in regulation of adult stem cell differentiation.

Study on multiple stem cell sources for mature vascular endothelial cells / 国际生物医学工程杂志

Stem cells offer considerable promise in the repair or replacement of damaged tissue in the body.Mature and functional endothelial cells play a pivotal role in neovascularization and maintenance of blood vessel integrity.Although being the best choice for transplantation endothelial,cells isolated from autologous vessels have been heavily obstacled in medical application due to poor resources and limitted proliferation potential in culture.Thus,stem cells have been the focus of the studies soareh for suitable cell sources.Several types of stem cells have been reported to possess endothelial cell differentiation potential.This article summarized the recent study on the sources,distribution,features-differentiation,animal experiments and clinical use of stem cells.Advantages and disadvantages are compared to provide a reference for the choice of evdothelial celia source.

Isolation and Culture of Adult Neural Stem Cells from Guinea Pig Tympanic Membrane / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Tympanic membrane perforation is an important clinical problem found in various populations of the world. In large number of cases, acute traumatic perforations heal spontaneously, and in the healing process, stem cells appear to play an important role. However, no studies have been reported regarding somatic stem cells in the tympanic membrane. Herein, we tried to show that guinea pig's tympanic membrane contains cells that display the characteristic features of stem cells. MATERIALS AND METHOD: The tympanic membrane was obtained from the guinea pig. The cells were cultured in a medium with epidermal growth factor (EGF) and fibroblast growth factor (FGF). Proliferating cells were checked with stem cell markers, bromodeoxyuridine (BrdU) and nestin. Differentiated cells from stem cells are checked with betaIII tubulin and S-100. RESULTS: We observed that some of the cultured cells from the tympanic membrane were stained with both stem cell markers, BrdU and nestin. And we observed that these cells differentiated into neuron and gilal cells, which expressed betaIII tubulin and S-100, respectively. CONCLUSION: These results suggest that the tympanic membrane of guinea pigs may have neural stem cells. Further study is needed for finding the origin of stem cells.

Isolation of porcine multipotential skin-derived precursor cells and its multilineage differentiation

There are increasing reports regarding regeneration of the defected tissues using tissue engineering technique. In this technique, multipotential stem cells are essential. There are many potential sources of adult stem cells, such as bone marrow, umbilical cord blood, fat, muscle, dental tissues and skin. Among them, skin is highly accessible and easily obtained with a minimum of donor site complications. Moreover, skin is an abundant adult stem cell sources and has the potential for self-replication and immune privilege. In this study, we isolated skin-derived precursor cells (SKPs) from the ear of adult miniature pigs. In these SKPs, the expression of transcriptional factors, Oct-4, Sox-2, and Nanog were detected by RT-PCR. In vitro osteogenesis and adipogenesis were observed at 3 weeks after transdifferentiations as assayed by positive von Kossa and Oil-red O staining, respectively. In addition, expression of osteocalcin and osteonectin in the osteogenic differentiation medium and PPAR GAMMA2 and aP2 in the adipogenic differentiation medium were detected by RT-PCR. In vitro neurogenesis of porcine SKPs was observed during 24 and 72 hours after treatment of neurogenic differentiation medium. The results of this study suggest that SKPs demonstrate the properties of pluripotence or multipotence and multi-lineage differentiation. This indicates that autogenous SKPs are a reliable and useful source of adult stem cells for regenerative medicine.

The Expression of Label-retaining Cells (LRCs) in Developing Rat Kidney / 대한해부학회지

Adult stem cells often have a low cycling rate and contribute to repair after injury by self-renewal and multiple cell division. In this study, we investigated the changes of the expression of label-retaining cells (LRCs) in developing rat kidneys which administered 5-bromo-2'-deoxy-uridine (BrdU) at embryonic day 18. In the cortex, BrdU-positive cells are localized mainly at embryonic day 18 and 20, but BrdU-positive cells after birth were rapidly decreased and almost not observed at day 14 after birth. In the medulla, the numerous BrdU-positive cells were markedly decreased in outer medulla at day 1 after birth and initial part of inner medulla at day 4 and 14 after birth, while the expression of BrdU-positive cells in the middle part (IMm) and terminal part of inner medulla (IMt) were not changes. At day 31 after birth as well as adult, BrdU-positive cells were remained in the IMm and IMt, which were mainly localized inner medullary collecting duct except a few BrdU-positive cells in the interstitium. Taken together, these observations suggest that the expression of LRCs were moved from cortex to medulla in developing kidney and the most LRCs are localized among renal epithelial tubular cells of the renal papilla in adult rat kidney.

Effect of Adult Bone Marrow Stem Cells on Myocardial Regeneration in Doxorubicin-Induced Mouse Cardiomyopathy

BACKGROUND AND OBJECTIVES: Bone marrow cells have been shown to differentiate into various cell lineages, including cardiomyocytes, in recent studies. This study evaluates the hypothesis that intravenous injection of bone marrow mononuclear cells (BMNCs) into rats with doxorubicin-induced cardiomyopathy can induce myocardial regeneration and improve myocardial contractility. MATERIALS AND METHODS: Adult male Sprague-Dawley rats were induced to develop cardiomyopathy by treatment with doxorubicin (2.5 mg/kg, 6 times, 2-week period). Stem cell enriched BMNCs were injected into the tail vein of the rats after cessation of the doxorubicin injections. One week after the injection of PKH-67-labeled BMNCs, the localization of transplanted cells was evaluated. Immunohistochemical studies and Western blots were performed two weeks after BMNCs injection. RESULTS: Cell-treated animals showed significant improvement in left ventricular fractional shortening as compared to untreated (control) rats (cell treated group vs. control group 47.2+/-4.9% vs. 34.4+/-3.6%, p<0.01). Histological analyses showed that in the cell-treated animals there was an increase in ventricular interstitial collagen deposition and the cell-treated animals had an improved number of capillary endothelial cells as compared with the control rats. PKH-67-labeled BMNCs and cell proliferation by BrdU was noted in the cell-treated hearts. Cardiac CXCR4 protein expression increased at day 7 and 14 in the cell-treated rats, but only at day 14 in the control animals. CONCLUSION: These results suggest that intravenous injection of BMNCs effectively induce engraftment of BMNCs into the myocardium and attenuation of fibrosis. Intravenous injection of BMNCs also improved myocardial contractility in doxorubicininduced cardiomyopathy.

Locations of Slow-Cycling Cells, Adult Stem Cells, in the Organs of Adult Mouse / 대한해부학회지

Adult stem cells possess the characteristics of self-renewal, multipotent, plasticity as well as slow cycling rate. We investigated a location of slow-cycling cells, that is, adult stem-like cells, in various organs in the 8 week-old mice which administered bromodeoxyuridine (BrdU) at neonatal phase. BrdU-retaining cells (slow-cycling cells) were observed in speramtogonia at the edge of seminiferous tubules in testes, hair root cells surrounding hair follicles, the cells in the inner nuclear layer of the retina, the myocytes in the hearts, the cells in the parenchyma and the Glisson's capsule of liver, the cells in the epithelial layer of bronchioles, and the tubular epithelial cells in the kidneys. In conclusion, various organs of adult mouse expressed slow-cycling cells, indicating that the cells may associate with normal cell turnover and repair after damages.

Stem cells / Células-tronco

Stem cells can be classified as embryonic stem (ES) cells or adult stem cells considering their origin. If plasticity is considered, stem cells can be classified as totipotent, when stem cells retain the ability to give rise to an entire new organism. When stem cells lose this capacity, cells are named pluripotent stem cells, which can give rise to almost all mature cell types that compound an organism. Totipotent and pluripotent stem cells can be obtained from developing early-stage embryos. Multipotent is the group of adult stem cells with restricted plasticity. These cells can differentiate into a defined cell type related with a specific organ or tissue. ES cells can be propagated in vitro under undifferentiated system or with a series of protocols to induce cell differentiation. On the other hand, multipotent adult stem cells cannot be maintained in vitro in an undifferentiated form, except for a special class of adherent adult stem cells named mesenchimal stem cells, which can be expanded in vitro conserving their undifferentiated characteristics. Considering the ability to generate teratomas, ES cells were not used in experimental in vivo cell transplant. On the other hand, several experimental adult stem cells transplants have been performed with controversial results

Considerando a origem de obtenção, as células-tronco podem ser classificadas como células-tronco embrionárias (ES) ou como células-tronco adultas. Mas, se a plasticidade for considerada, as células-tronco podem ser classificadas como células totipotentes, quando as células-tronco preservam a capacidade de dar origem a um novo indivíduo completo. Quando as células-tronco perdem esta capacidade, passam a ser classificadas como células-tronco pluripotentes, que podem dar origem a praticamente todos os tipos celulares maduros que compõem um organismo. Células-tronco totipotentes e pluripotentes podem ser obtidas de estágios embrionários iniciais. O grupo de células-tronco que apresenta plasticidade restrita é denominado de multipotente. Estas células podem se diferenciar em determinado tipo celular comprometido com um órgão ou tecido específico. Células ES podem ser expandidas in vitro, mantendo sua forma indiferenciada, ou podem ser submetidas a uma série de protocolos, que irão induzir diferenciação in vitro. Por outro lado, as células-tronco adultas multipotentes não podem ser mantidas in vitro na forma indiferenciada, exceto uma subpopulação de célulastronco adultas aderentes, denominadas células-tronco mesenquimais, que podem ser mantidas in vitro na forma indiferenciada. Considerando a capacidade de gerar teratomas, as células ES não foram utilizadas para transplante celular experimental in vivo. Além disso, várias cirurgias de transplantes experimentais com células-tronco adultas têm sido realizadas, porém apresentando resultados controversos