Células tronco e endodontia regenerativa / Stem cells and regenerative endodontics

Desde o incremento das pesquisas das células-tronco em 1961, por cientistas canadenses, os avanços em estudos, pesquisas e o desenvolvimento de novos tratamentos com esse tipo de recurso se mostram promissores. O uso de células-tronco é uma grande aposta tanto para a medicina quanto para a odontologia regenerativa. Os tratamentos com essa terapia podem oferecer mais qualidade de vida para as pessoas. O potencial dessas células tão especiais se encontra em duas características peculiares: elas são capazes de se multiplicarem e de se diferenciarem em outros tipos de células, como de tecidos, cartilagens e neurônios. É dessa maneira que elas têm um papel fundamental para estudos e tratamentos relacionados à regeneração. O uso de células-tronco na Odontologia torna possível diferentes processos odontológicos que oferecem mais qualidade de vida ao paciente. Isso porque fatores como defeitos genéticos, hábitos nocivos, cáries dentárias e perdas precoces dos dentes contribuem com a perda de dentes ao longo da vida. No início do século XXI, por volta dos anos de 2005, 2006, pesquisadores começaram a publicar em revistas internacionais da área uma nova técnica baseada no uso de célulastronco existentes no osso de sustentação dos dentes e na articulação dento alveolar. Esta técnica, chamada de Revascularização, promove o aparecimento de um novo tecido pulpar sadio, devolvendo ao dente sua vitalidade e higidez(AU)

Since the increase in stem cell research in 1961 by Canadian scientists, advances in studies, research and the development of new treatments with this type of resource have shown promise. The use of stem cells is a big bet for both medicine and regenerative dentistry. Treatments with this therapy can offer more quality of life for people. The potential of these very special cells lies in two peculiar characteristics: they are able to multiply and differentiate into other types of cells, such as tissues, cartilage and neurons. It is in this way that they play a key role for studies and treatments related to regeneration. The use of stem cells in dentistry makes possible different dental processes that offer more quality of life to the patient. That's because factors such as genetic defects, harmful habits, tooth decay, and early tooth loss all contribute to lifelong tooth loss. At the beginning of the twenty-first century, around the years 2005, 2006, researchers began to publish in international journals of the area a new technique based on the use of existing stem cells in the supporting bone of the teeth and in the alveolar tooth joint. This technique, called Revascularization, promotes the appearance of a new healthy pulp tissue, returning to the tooth its vitality and hygiene(AU)

Criopreservação de células-tronco mesenquimais do tecido adiposo: Uma alternativa para lipoenxertia seriada na reconstrução mamária / Cryopreservation of adipose tissue-derived mesenchymal stem cells: An alternative to serial fat grafting in breast reconstruction

Introdução: A lipoenxertia é um enxerto autólogo de células do tecido celular subcutâneo, que pode ser utilizada como técnica complementar na reconstrução mamária. Diante disso, a criopreservação de células-tronco mesenquimais provenientes de tecido adiposo (CTDAs) poderia ser uma maneira de realizar a coleta em um tempo cirúrgico e após realizar a lipoenxertia de forma fracionada. O dimetilsulfóxido (DMSO) é um criopreservante utilizado em pesquisas com células, porém é potencialmente tóxico, o que impossibilitaria a utilização de CTDAs criopreservadas na prática clínica. Novos criopreservantes celulares, sem toxicidade, vêm sendo descritos na literatura científica experimental, como as substâncias L-prolina e trealose. Com isso, esse trabalho teve como objetivo avaliar a viabilidade de CTDAs criopreservadas com a combinação de L-prolina e trealose, em um período de até 90 dias. Método: Estudo experimental, no qual foram obtidas amostras de lipoaspirado provenientes de 9 pacientes. A fração celular foi processada e congelada com L-prolina (1,5M) + trealose (0,2M), ou com DMSO + soro fetal bovino (SFB), como controle. Após 30 e 90 dias, as amostras foram descongeladas e a viabilidade celular foi avaliada pela técnica de MTT. Resultados: A análise das CTDAs, após 1 e 3 meses de congelamento, indicou que as amostras tratadas com L-prolina + trealose apresentaram viabilidade semelhante àquelas preservadas com DMSO e SFB (p=0,444). Conclusão: A associação de L-prolina e trealose manteve CTDA viáveis por 30 e 90 dias de congelamento, podendo ser uma alternativa como criopreservante celular sem toxicidade e viabilizando o uso de lipoenxertia seriada.

Introduction: Fat grafting is an autologous graft of cells from subcutaneous tissue, which can be used as a complementary technique in breast reconstruction. Given this, the cryopreservation of adipose tissue-derived mesenchymal stem cells (ADMSCs) could be a way to collect them in one surgical procedure and after performing fractional fat grafting. Dimethyl sulfoxide (DMSO) is a cryopreservative used in cell research, but it is potentially toxic, which would make it impossible to use cryopreserved ADMSCs in clinical practice. New cellular cryopreservatives, without toxicity, have been described in the experimental scientific literature, such as the substances L-proline and trehalose. Therefore, this work aimed to evaluate the viability of ADMSCs cryopreserved with the combination of L-proline and trehalose over up to 90 days. Method: Experimental study in which lipoaspirate samples were obtained from 9 patients. The cellular fraction was processed and frozen with L-proline (1.5M) + trehalose (0.2M) or with DMSO + fetal bovine serum (FBS) as control. After 30 and 90 days, the samples were thawed, and cell viability was assessed using the MTT technique. Results: The analysis of ADMSCs, after 1 and 3 months of freezing, indicated that samples treated with L-proline + trehalose showed similar viability to those preserved with DMSO and SFB (p=0.444). Conclusion: The association of L-proline and trehalose kept ADMSC viable for 30 and 90 days of freezing, and could be an alternative as a cellular cryopreservative without toxicity and enabling the use of serial fat grafting.

Stimulation of mouse hematopoietic stem cells by angiogenin and DNA preparations

Immature hematopoietic progenitors are a constant source for renewal of hemocyte populations and the basic component of the tissue and cell repair apparatus. A unique property of these cells of internalizing extracellular double-stranded DNA has been previously shown. The leukostimulatory effect demonstrated in our pioneering studies was considered to be due to the feature of this cell. In the present research, we have analyzed the effects of DNA genome reconstructor preparation (DNAgr), DNAmix, and human recombinant angiogenin on both hematopoietic stem cells and multipotent progenitors. Treatment with bone marrow cells of experimental mice with these preparations stimulates colony formation by hematopoietic stem cells and proliferation of multipotent descendants. The main lineage responsible for this is the granulocyte-macrophage hematopoietic lineage. Using fluorescent microscopy as well as FACS assay, co-localization of primitive c-Kit- and Sca-1-positive progenitors and the TAMRA-labeled double-stranded DNA has been shown. Human recombinant angiogenin was used as a reference agent. Cells with specific markers were quantified in intact bone marrow and colonies grown in the presence of inducers. Quantitative analysis revealed that a total of 14,000 fragment copies of 500 bp, which is 0.2% of the haploid genome, can be delivered into early progenitors. Extracellular double-stranded DNA fragments stimulated the colony formation in early hematopoietic progenitors from the bone marrow, which assumed their effect on cells in G0. The observed number of Sca1+/c-Kit+ cells in colonies testifies to the possibility of both symmetrical and asymmetrical division of the initial hematopoietic stem cell and its progeny.

Resveratrol Alleviates Osteoporosis by Promoting Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells via SITR1/PI3K/AKT Pathway / El Resveratrol Alivia la Osteoporosis al Promover la Diferenciación Osteogénica de las Células Madre Mesenquimales de la Médula Ósea a Través de la Vía SITR1/PI3K/AKT

SUMMARY: Senile osteoporosis is mainly caused by reduced osteoblast differentiation and has become the leading cause of fractures in the elderly worldwide. Natural organics are emerging as a potential option for the prevention and treatment of osteoporosis. This study was designed to study the effect of resveratrol on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in osteoporosis mice. A mouse model of osteoporosis was established by subcutaneous injection of dexamethasone and treated with resveratrol administered by gavage. In vivo and in vitro, we used western blot to detect protein expression, and evaluated osteogenic differentiation of BMSCs by detecting the expression of osteogenic differentiation related proteins, calcium deposition, ALP activity and osteocalcin content. Resveratrol treatment significantly increased the body weight of mice, the level of serum Ca2+, 25(OH)D and osteocalcin, ration of bone weight, bone volume/total volume, trabecular thickness, trabecular number, trabecular spacing and cortical thickness in osteoporosis mice. In BMSCs of osteoporosis mice, resveratrol treatment significantly increased the expression of Runx2, osterix (OSX) and osteocalcin (OCN) protein, the level of calcium deposition, ALP activity and osteocalcin content. In addition, resveratrol treatment also significantly increased the expression of SIRT1, p-PI3K / PI3K and p-AKT / AKT in BMSCs of osteoporosis mice. In vitro, resveratrol increased the expression of SIRT1, p-PI3K / PI3K and p-AKT / AKT, Runx2, OSX and OCN protein, the level of calcium deposition, ALP activity and osteocalcin content in BMSCs in a concentration-dependent manner, while SIRT1 knockdown significantly reversed the effect of resveratrol. Resveratrol can attenuate osteoporosis by promoting osteogenic differentiation of bone marrow mesenchymal stem cells, and the mechanism may be related to the regulation of SIRT1/PI3K/AKT pathway.

La osteoporosis senil es causada principalmente por una diferenciación reducida de osteoblastos y se ha convertido en la principal causa de fracturas en las personas mayores en todo el mundo. Los productos orgánicos naturales están surgiendo como una opción potencial para la prevención y el tratamiento de la osteoporosis. Este estudio fue diseñado para estudiar el efecto del resveratrol en la diferenciación osteogénica de las células madre mesenquimales de la médula ósea (BMSC) en ratones con osteoporosis. Se estableció un modelo de osteoporosis en ratones mediante inyección subcutánea de dexametasona y se trató con resveratrol administrado por sonda. In vivo e in vitro, utilizamos Western blot para detectar la expresión de proteínas y evaluamos la diferenciación osteogénica de BMSC detectando la expresión de proteínas relacionadas con la diferenciación osteogénica, la deposición de calcio, la actividad de ALP y el contenido de osteocalcina. El tratamiento con resveratrol aumentó significativamente el peso corporal de los ratones, el nivel sérico de Ca2+, 25(OH)D y osteocalcina, la proporción de peso óseo, el volumen óseo/ volumen total, el espesor trabecular, el número trabecular, el espaciado trabecular y el espesor cortical en ratones con osteoporosis. En BMSC de ratones con osteoporosis, el tratamiento con resveratrol aumentó significativamente la expresión de las proteínas Runx2, osterix (OSX) y osteocalcina (OCN), el nivel de deposición de calcio, la actividad de ALP y el contenido de osteocalcina. Además, el tratamiento con resveratrol también aumentó significativamente la expresión de SIRT1, p-PI3K/PI3K y p-AKT/AKT en BMSC de ratones con osteoporosis. In vitro, el resveratrol aumentó la expresión de las proteínas SIRT1, p-PI3K/PI3K y p- AKT/AKT, Runx2, OSX y OCN, el nivel de deposición de calcio, la actividad de ALP y el contenido de osteocalcina en BMSC de manera dependiente de la concentración, mientras que La caída de SIRT1 revirtió significativamente el efecto del resveratrol. El resveratrol puede atenuar la osteoporosis al promover la diferenciación osteogénica de las células madre mesenquimales de la médula ósea, y el mecanismo puede estar relacionado con la regulación de la vía SIRT1/PI3K/AKT.

Influence of the addition of nanohydroxyapatite to scaffolds on proliferation and differentiation of human mesenchymal stem cells: a systematic review of in vitro studies

One of the main challenges of tissue engineering in dentistry is to replace bone and dental tissues with strategies or techniques that simulate physiological tissue repair conditions. This systematic review of in vitro studies aimed to evaluate the influence of the addition of nanohydroxyapatite (NHap) to scaffolds on cell proliferation and osteogenic and odontogenic differentiation of human mesenchymal stem cells. In vitro studies on human stem cells that proliferated and differentiated into odontogenic and osteogenic cells in scaffolds containing NHap were included in this study. Searches in PubMed/MEDLINE, Scopus, Web of Science, OpenGrey, ProQuest, and Cochrane Library electronic databases were performed. The total of 333 articles was found across all databases. After reading and analyzing titles and abstracts, 8 articles were selected for full reading and extraction of qualitative data. Results showed that despite the large variability in scaffold composition, NHap-containing scaffolds promoted high rates of cell proliferation, increased alkaline phosphatase (ALP) activity during short culture periods, and induced differentiation, as evidenced by the high expression of genes involved in osteogenesis and odontogenesis. However, further studies with greater standardization regarding NHap concentration, type of scaffolds, and evaluation period are needed to observe possible interference of these criteria in the action of NHap on the proliferation and differentiation of human stem cells.

Common mental disorders in hematopoietic stem cell transplant patients: a scoping review / Trastornos mentales comunes en pacientes con trasplante de células madre hematopoyéticas: revisión del alcance / Transtornos mentais comuns em pacientes transplantados com células-tronco hematopoéticas: revisão de escopo

ABSTRACT Objective: to map common recurrent mental disorders in patients undergoing hematopoietic stem cell transplantation. Methods: this is a scoping review carried out in January 2022 in electronic databases and repositories of dissertations and thesis. Studies that answered the research question, met the objective of the study and were available in full electronically, in any language, were included. Results: the sample consisted of 28 studies, 14 of which were published in the United States of America. The common mental disorders found were depressive, anxiety, post-traumatic stress and mood disorders. Twenty symptoms were mentioned, among the most prevalent are fatigue and sleep disorders/insomnia. Conclusions: the difficulty and importance of carrying out the differential diagnosis of these disorders were highlighted, since their symptoms can be confused with other health problems and have a strong potential to interfere with patients' evolution.

RESUMEN Objetivo: mapear los trastornos mentales recurrentes comunes en pacientes sometidos a trasplante de células madre hematopoyéticas. Métodos: se trata de una revisión de alcance realizada en enero de 2022 en bases de datos electrónicas y repositorios de disertaciones y tesis. Se incluyeron publicaciones que respondieron a la pregunta de investigación, cumplieron con el objetivo del estudio y estaban disponibles en su totalidad en formato electrónico, en cualquier idioma. Resultados: la muestra estuvo compuesta por 28 estudios, 14 de los cuales fueron publicados en los Estados Unidos de América. Los trastornos mentales comunes encontrados fueron depresión, ansiedad, estrés postraumático y trastornos del estado de ánimo. Se mencionaron 20 síntomas, entre los más prevalentes se encuentran fatiga y trastornos del sueño/insomnio. Conclusiones: se destacó la dificultad e importancia de realizar el diagnóstico diferencial de estos trastornos, ya que sus síntomas pueden confundirse con otros problemas de salud y tienen un fuerte potencial de interferir en la evolución del paciente.

RESUMO Objetivo: mapear os transtornos mentais comuns recorrentes em pacientes submetidos ao transplante de células-tronco hematopoéticas. Métodos: trata-se de revisão de escopo realizada em janeiro de 2022 em bases de dados eletrônicas e repositórios de dissertações e tese. Foram incluídas publicações que respondessem à questão de pesquisa, atendessem ao objetivo do estudo e que estivessem disponíveis na íntegra em meio eletrônico, em qualquer idioma. Resultados: a amostra foi composta por 28 estudos, dos quais 14 foram publicados nos Estados Unidos da América. Os transtornos mentais comuns encontrados foram os transtornos depressivos, de ansiedade, estresse pós-traumático e de humor. Foram citados 20 sintomas, entre os mais prevalentes estão a fadiga e distúrbios do sono/insônia. Conclusões: evidenciaram-se a dificuldade e a importância de realizar o diagnóstico diferencial desses transtornos, uma vez que seus sintomas podem ser confundidos com outros problemas de saúde e têm forte potencial para interferir na evolução do paciente.

Cobalt Chloride as a Hypoxia Mimicking Agent Induced HIF-1α and mTOR Expressions of Human Umbilical Cord Mesenchymal Stem Cells

ABSTRACT Objective: To assess the effects of cobalt chloride (CoCl2) as a hypoxia mimicking agent on human umbilical cord mesenchymal stem cells (hUCMSCs) expression of HIF-1α and mTOR for use in regenerative dentistry. Material and Methods: Human umbilical cord mesenchymal stem cells were isolated and then cultured. The characteristics of stemness were screened and confirmed by flow cytometry. The experiment was conducted on hypoxia (H) and normoxia (N) groups. Each group was divided and incubated into 24-, 48-, and 72-hours observations. Hypoxic treatment was performed using 100 µM CoCl2 on 5th passage cells in a conventional incubator (37°C; 5CO2). Then, immunofluorescence of HIF-1α and mTOR was done. Data was analyzed statistically using One-way ANOVA and Tukey's HSD. Results: Significant differences were found between normoxic and hypoxic groups on HIF-1α (p=0.015) and mTOR (p=0.000) expressions. The highest HIF-1α expression was found at 48 hours in the hypoxia group, while for mTOR at 24 hours in the hypoxia group. Conclusion: Hypoxia using cobalt chloride was able to increase human umbilical cord mesenchymal stem cells expression of HIF-1α and mTOR.

Endometrial mesenchymal stromal/stem cells improve regeneration of injured endometrium in mice

BACKGROUND: The monthly regeneration of human endometrial tissue is maintained by the presence of human endometrial mesenchymal stromal/stem cells (eMSC), a cell population co-expressing the perivascular markers CD140b and CD146. Endometrial regeneration is impaired in the presence of intrauterine adhesions, leading to infertility, recurrent pregnancy loss and placental abnormalities. Several types of somatic stem cells have been used to repair the damaged endometrium in animal models, reporting successful pregnancy. However, the ability of endometrial stem cells to repair the damaged endometrium remains unknown. METHODS: Electrocoagulation was applied to the left uterine horn of NOD/SCID mice causing endometrial injury. Human eMSC or PBS was then injected into the left injured horn while the right normal horn served as controls. Mice were sacrificed at different timepoints (Day 3, 7 and 14) and the endometrial morphological changes as well as the degree of endometrial injury and repair were observed by histological staining. Gene expression of various inflammatory markers was assessed using qPCR. The functionality of the repaired endometrium was evaluated by fertility test. RESULTS: Human eMSC successfully incorporated into the injured uterine horn, which displayed significant morphological restoration. Also, endometrium in the eMSC group showed better cell proliferation and glands formation than the PBS group. Although the number of blood vessels were similar between the two groups, gene expression of VEGF-α significantly increased in the eMSC group. Moreover, eMSC had a positive impact on the regeneration of both stromal and epithelial components of the mouse endometrium, indicated by significantly higher vimentin and CK19 protein expression. Reduced endometrial fibrosis and down-regulation of fibrosis markers were also observed in the eMSC group. The eMSC group had a significantly higher gene expression of anti-inflammatory factor Il-10 and lower mRNA level of pro-inflammatory factors Ifng and Il-2, indicating the role of eMSC in regulation of inflammatory reactions. The eMSC group showed higher implantation sites than the PBS group, suggesting better endometrial receptivity with the presence of newly emerged endometrial lining. CONCLUSIONS: Our findings suggest eMSC improves regeneration of injured endometrium in mice.

Advances in mesenchymal stem cells therapy for tendinopathies / 中华创伤杂志(英文版)

Tendinopathies are chronic diseases of an unknown etiology and associated with inflammation. Mesenchymal stem cells (MSCs) have emerged as a viable therapeutic option to combat the pathological progression of tendinopathies, not only because of their potential for multidirectional differentiation and self-renewal, but also their excellent immunomodulatory properties. The immunomodulatory effects of MSCs are increasingly being recognized as playing a crucial role in the treatment of tendinopathies, with MSCs being pivotal in regulating the inflammatory microenvironment by modulating the immune response, ultimately contributing to improved tissue repair. This review will discuss the current knowledge regarding the application of MSCs in tendinopathy treatments through the modulation of the immune response.

Research advances on stem cell-based treatments in animal studies and clinical trials of lymphedema / 中国修复重建外科杂志

OBJECTIVE@#To summarize the progress of the roles and mechanisms of various types of stem cell-based treatments and their combination therapies in both animal studies and clinical trials of lymphedema.@*METHODS@#The literature on stem cell-based treatments for lymphedema in recent years at home and abroad was extensively reviewed, and the animal studies and clinical trials on different types of stem cells for lymphedema were summarized.@*RESULTS@#Various types of stem cells have shown certain effects in animal studies and clinical trials on the treatment of lymphedema, mainly through local differentiation into lymphoid endothelial cells and paracrine cytokines with different functions. Current research focuses on two cell types, adipose derived stem cells and bone marrow mesenchymal stem cells, both of which have their own advantages and disadvantages, mainly reflected in the therapeutic effect of stem cells, the difficulty of obtaining stem cells and the content in vivo. In addition, stem cells can also play a synergistic role in combination with other treatments, such as conservative treatment, surgical intervention, cytokines, biological scaffolds, and so on. However, it is still limited to the basic research stage, and only a small number of studies have completed clinical trials.@*CONCLUSION@#Stem cells have great transformation potential in the treatment of lymphedema, but there is no unified standard in the selection of cell types, the amount of transplanted cells, and the timing of transplantation.

Study on injectable chitosan hydrogel with tendon-derived stem cells for enhancing rotator cuff tendon-to-bone healing / 中国修复重建外科杂志

OBJECTIVE@#To explore the effect of chitosan (CS) hydrogel loaded with tendon-derived stem cells (TDSCs; hereinafter referred to as TDSCs/CS hydrogel) on tendon-to-bone healing after rotator cuff repair in rabbits.@*METHODS@#TDSCs were isolated from the rotator cuff tissue of 3 adult New Zealand white rabbits by Henderson step-by-step enzymatic digestion method and identified by multidirectional differentiation and flow cytometry. The 3rd generation TDSCs were encapsulated in CS to construct TDSCs/CS hydrogel. The cell counting kit 8 (CCK-8) assay was used to detect the proliferation of TDSCs in the hydrogel after 1-5 days of culture in vitro, and cell compatibility of TDSCs/CS hydrogel was evaluated by using TDSCs alone as control. Another 36 adult New Zealand white rabbits were randomly divided into 3 groups ( n=12): rotator cuff repair group (control group), rotator cuff repair+CS hydrogel injection group (CS group), and rotator cuff repair+TDSCs/CS hydrogel injection group (TDSCs/CS group). After establishing the rotator cuff repair models, the corresponding hydrogel was injected into the tendon-to-bone interface in the CS group and TDSCs/CS group, and no other treatment was performed in the control group. The general condition of the animals was observed after operation. At 4 and 8 weeks, real-time quantitative PCR (qPCR) was used to detect the relative expressions of tendon forming related genes (tenomodulin, scleraxis), chondrogenesis related genes (aggrecan, sex determining region Y-related high mobility group-box gene 9), and osteogenesis related genes (alkaline phosphatase, Runt-related transcription factor 2) at the tendon-to-bone interface. At 8 weeks, HE and Masson staining were used to observe the histological changes, and the biomechanical test was used to evaluate the ultimate load and the failure site of the repaired rotator cuff to evaluate the tendon-to-bone healing and biomechanical properties.@*RESULTS@#CCK-8 assay showed that the CS hydrogel could promote the proliferation of TDSCs ( P<0.05). qPCR results showed that the expressions of tendon-to-bone interface related genes were significantly higher in the TDSCs/CS group than in the CS group and control group at 4 and 8 weeks after operation ( P<0.05). Moreover, the expressions of tendon-to-bone interface related genes at 8 weeks after operation were significantly higher than those at 4 weeks after operation in the TDSCs/CS group ( P<0.05). Histological staining showed the clear cartilage tissue and dense and orderly collagen formation at the tendon-to-bone interface in the TDSCs/CS group. The results of semi-quantitative analysis showed that compared with the control group, the number of cells, the proportion of collagen fiber orientation, and the histological score in the TDSCs/CS group increased, the vascularity decreased, showing significant differences ( P<0.05); compared with the CS group, the proportion of collagen fiber orientation and the histological score in the TDSCs/CS group significantly increased ( P<0.05), while there was no significant difference in the number of cells and vascularity ( P>0.05). All samples in biomechanical testing failed at the repair site during the testing process. The ultimate load of the TDSCs/CS group was significantly higher than that of the control group ( P<0.05), but there was no significant difference compared to the CS group ( P>0.05).@*CONCLUSION@#TDSCs/CS hydrogel can induce cartilage regeneration to promote rotator cuff tendon-to-bone healing.

Impact of lithocholic acid on the osteogenic and adipogenic differentiation balance of bone marrow mesenchymal stem cells / 中国修复重建外科杂志

OBJECTIVE@#To Investigate the effects of lithocholic acid (LCA) on the balance between osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).@*METHODS@#Twelve 10-week-old SPF C57BL/6J female mice were randomly divided into an experimental group (undergoing bilateral ovariectomy) and a control group (only removing the same volume of adipose tissue around the ovaries), with 6 mice in each group. The body mass was measured every week after operation. After 4 weeks post-surgery, the weight of mouse uterus was measured, femur specimens of the mice were taken for micro-CT scanning and three-dimensional reconstruction to analyze changes in bone mass. Tibia specimens were taken for HE staining to calculate the number and area of bone marrow adipocytes in the marrow cavity area. ELISA was used to detect the expression of bone turnover markers in the serum. Liver samples were subjected to real-time fluorescence quantitative PCR (RT-qPCR) to detect the expression of key genes related to bile acid metabolism, including cyp7a1, cyp7b1, cyp8b1, and cyp27a1. BMSCs were isolated by centrifugation from 2 C57BL/6J female mice (10-week-old). The third-generation cells were exposed to 0, 1, 10, and 100 μmol/L LCA, following which cell viability was evaluated using the cell counting kit 8 assay. Subsequently, alkaline phosphatase (ALP) staining and oil red O staining were conducted after 7 days of osteogenic and adipogenic induction. RT-qPCR was employed to analyze the expressions of osteogenic-related genes, namely ALP, Runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), as well as adipogenic-related genes including Adiponectin (Adipoq), fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor γ (PPARγ).@*RESULTS@#Compared with the control group, the body mass of the mice in the experimental group increased, the uterus atrophied, the bone mass decreased, the bone marrow fat expanded, and the bone metabolism showed a high bone turnover state. RT-qPCR showed that the expressions of cyp7a1, cyp8b1, and cyp27a1, which were related to the key enzymes of bile acid metabolism in the liver, decreased significantly ( P<0.05), while the expression of cyp7b1 had no significant difference ( P>0.05). Intervention with LCA at concentrations of 1, 10, and 100 μmol/L did not demonstrate any apparent toxic effects on BMSCs. Furthermore, LCA inhibited the expressions of osteogenic-related genes (ALP, Runx2, and OCN) in a dose-dependent manner, resulting in a reduction in ALP staining positive area. Concurrently, LCA promoted the expressions of adipogenic-related genes (Adipoq, FABP4, and PPARγ), and an increase in oil red O staining positive area.@*CONCLUSION@#After menopause, the metabolism of bile acids is altered, and secondary bile acid LCA interferes with the balance of osteogenic and adipogenic differentiation of BMSCs, thereby affecting bone remodelling.

Reconstruction of rat calvarial defects utilizing an ultraviolet-cured hydrogel loaded with bone marrow mesenchymal stem cells / 口腔疾病防治

Objective@#To investigate the osteogenic properties of a methacrylated gelatin (GelMA) / bone marrow mesenchymal stem cells (BMSCs) composite hydrogel applied to the skull defect area of rats and to provide an experimental basis for the development of bone regeneration biomaterials.@*Methods@#This study was approved by the Animal Ethics Committee of Nanjing University. A novel photocurable composite biohydrogel was developed by constructing photoinitiators [lthium phenyl (2,4,6-trimethylbenzoyl) phosphinate, LAP], GelMA, and BMSCs. The surface morphology and elemental composition of the gel were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The compressive strength of the gel was evaluated using an electronic universal testing machine. After in vitro culture for 1, 2, and 5 days, the proliferation of the BMSCs in the hydrogels was assessed using a CCK-8 assay, and their survival and morphology were examined through confocal microscopy. A 5 mm critical bone deficiency model was generated in a rat skull. The group receiving composite hydrogel treatment was referred to as the GelMA/BMSCs group, whereas the untreated group served as the control group. At the 4th and 8th weeks, micro-CT scans were taken to measure the bone defect area and new bone index, while at the 8th week, skull samples from the defect area were subjected to H&E staining, van Gieson staining, and Goldner staining to evaluate the quality of bone regeneration and new bone formation.@*Results@#SEM observed that the solidified GelMA showed a 3D spongy gel network with uniform morphology, the porosity of GelMA was 73.41% and the pore size of GelMA was (28.75 ± 7.13) μm. EDX results showed that C and O were evenly distributed in the network macroporous structure of hydrogel. The hydrogel compression strength was 152 kPa. On the 5th day of GelMA/BMSCs culture, the cellular morphology transitioned from oval to spindle shaped under microscopic observation, accompanied by a significant increase in cell proliferation (159.4%, as determined by the CCK-8 assay). At 4 weeks after surgery, a 3D reconstructed micro-CT image revealed a minimal reduction in bone defect size within the control group and abundant new bone formation in the GelMA/BMSCs group. At 8 weeks after surgery, no significant changes were observed in the control group's bone defect area, with only limited evidence of new bone growth; however, substantial healing of skull defects was evident in the GelMA/BMSCs group. Quantitative analysis at both the 4- and 8-week examinations indicated significant improvements in the new bone volume (BV), new bone volume/total bone volume (BV/TV), bone surface (BS), and bone surface/total bone volume (BS/TV) in the GelMA/BMSCs group compared to those in the control group (P<0.05). Histological staining showed continuous and dense formation of bone tissue within the defects in the GelMA/BMSCs group and only sporadic formation of new bone, primarily consisting of fibrous connective tissue, at the defect edge in the control group.@*Conclusion@#Photocuring hydrogel-based stem cell therapy exhibits favorable biosafety profiles and has potential for clinical application by inducing new bone formation and promoting maturation within rat skull defects.

Research progress on molecular mechanism of traditional chinese medicine active ingredients interfering bone marrow mesenchymal stem cells senescence / 中国临床药理学与治疗学

The senescence of bone marrow mesenchymal stem cells (BM-MSCs) will induce age-related bone tissue degeneration and chronic inflammation, and reduce its application effect for cell therapy. More and more active ingredients of traditional chinese medicine have been proved to intervene BM - MSCs senescence, playing an important role in bone diseases prevention and treatment, and improving the therapeutic effect of BM-MSCs. In this paper, the latest research progress on the molecular mechanism of traditional chinese medicine active ingredients interfering BM-MSCs senescence was summarized, in order to provide new direction and reference basis for senescence intervention research and clinical application improvement of BM-MSCs.

Advances in the study of mesenchymal stem cells in obstructive sleep apnea hypoventilation syndrome / 中国临床药理学与治疗学

Mesenchymal stem cells (MSCs) are self-regenerating, rapidly proliferating pluripotent stem cells that depend primarily on their derived pro-angiogenic, inflammatory regulatory, and trophic factors to exert beneficial effects that attenuate deleterious inflammatory responses, reduce vascular damage, and promote tissue repair and regeneration. Obstructive sleep apnea hypoventilation syndrome (OSAHS) is a chronic disorder marked by oropharyngeal collapse during sleep, resulting in transient reduced airflow, large fluctuations in intrathoracic pressure, and intermittent hypoxia and hypercapnia. OSAHS subsequently cytokine-mediated inflammatory cascades, oxidative stress, and ischemia, recruit MSCs from inflamed and damaged tissues through MSCs-derived of anti-inflammatory and pro-angiogenic factor activity, reduce hypoxia, suppress inflammation, promote regeneration, and prevent fibrosis in OSAHS-injured tissues. In this paper, we will describe the pathogenesis of inflammation, oxidative stress, fibrosis and ischemia from the perspective of OSAHS, highlighting the current research progress on MSCs-dependent regulation of OSAHS-related pathology.

Progress in the potential therapeutic mechanism of mesenchymal stem cell-derived exosomes for liver fibrosis / 中国临床药理学与治疗学

Liver fibrosis is pathological in most chronic liver diseases. Exosomes secreted by mesenchymal stem cells (MSCs) can regulate liver fibrosis through mechanisms such as inhibition of inflammatory response and proliferation of activated hepatic stellate cells, regulation of immune cells and metabolism. Therefore, MSC-derived exosomes can be used as a cell-free therapy for chronic liver disease, expanding new ideas for the treatment of chronic liver disease. Recent researches on MSC-derived exosomes in the treatment of liver fibrosis are reviewed in this article.

Effect of miR-141-5p/ZNF705A on adhesion of bone marrow mesenchymal stem cells in chronic myeloid leukemia cell-derived exosomes / 中国药理学通报

Aim To investigate the effect of miR-141-5p/ZNF705A in chronic myeloid leukemia(CML)cell-derived exosome(Exo)on the adhesion of bone marrow mesenchymal stem cells(BMSCs). Methods The morphology and size of Exo in peripheral blood from CML patients and K562 cells were examined by electron microscopy and NTA particle size analysis. The expressions of Exo and BMSCs marker molecules and adhesion proteins in K562 cells were detected by qRT-PCR and Western blot before and after transfection. The adhesion ability of BMSCs was detected by cell adhesion assay, and the cellular activity of BMSCs was examined using CCK-8. miR-141-5p binding to ZNF705A was detected by luciferase assay. Results qRT-PCR results showed that miR-141-5p expression was significantly reduced in both CML patients and K562 cell-derived Exo. qRT-PCR, Western blot and other results showed that BMSCs in CML patients had significantly reduced the expression of adhesion proteins CD44 and CXCL12, and were able to phagocytose K562 cell-derived Exo. Further, K562-derived Exo was found to reduce CD44 and CXCL12 expression and adhesion in Exo-promoted BMSCs compared with CD34+ cells. Meanwhile, the results of dual luciferase reporter assay verified that miR-141-5p targeted binding to ZNF705A. Finally, we found ZNF705A could be targeted by up-regulating miR-141-5p expression in Exo of K562 cells, which in turn inhibited the adhesion of BMSCs. Conclusions K562 cells down-regulate miR-141-5p expression in Exo and inhibit the adhesion function of BMSCs by targeting ZNF705A, thus regulating the bone marrow hematopoietic function in CML patients.

Optimization of extraction process of flavonoids from Broussonetia papyrifera leaves and its antioxidant effect on mouse epidermal stem cells / 中国生物制品学杂志

@#Objective To optimize the extraction process of flavonoids from Broussonetia papyrifera leaves and explore the antioxidant effect of flavonoids on mouse epidermal stem cells.Methods The extraction process of flavonoids from Broussonetia papyrifera leaves was optimized by single factor experiment,including the liquid-solid ratio(15:1,20:1,25:1,30:1and 35:1),sodium hydroxide(NaOH) concentration(0.2%,0.4%,0.6%,0.8% and 1.0%),pH value(2.5,3.0,3.5,4.0and 4.5) and extraction temperature(60,65,70,75 and 80℃).Based on the results of single factor experiment,the optimal extraction process was determined by orthogonal test with the mass fraction of flavonoids as the evaluation index.CD49f~+/CD71~-mouse epidermal stem cells were isolated and cultivated by immunomagnetic bead method,and the effects of flavonoids on the cell relative viability and the contents of reduced glutathione(GSH) and malondialdehyde(MDA) were detected.Results The optimal extraction conditions of flavonoids were liquid-solid ratio of 30:1,0.6% NaOH,pH 4.5and extraction temperature of 75 ℃.Under these conditions,the average mass fraction of flavonoids extracted was 1.47%.Compared with the negative control group,when the flavonoids final concentration was 25 and 50 μg/mL,the cell relative viability increased significantly(F=1.427 and 13.747 respectively,each P <0.01);when the final concentration of flavonoids was 12.5,25 and 50 μg/mL,the content of GSH increased significantly(F=0.044,0.291 and 2.577 respectively,each P <0.05) and the content of MDA decreased significantly(F=3.568,4.909 and 1.400 respectively,each P <0.05).Conclusion The optimized extraction process of flavonoids from B.papyrifera leaves was stable and reliable,which is beneficial to the reuse of remaining stock solution after processing,and the extracted flavonoids can promote the proliferation of mouse epidermal stem cells and perform antioxidant activity.

Role of mesenchymal stem cells and their exosomes in the treatment of drug-induced liver injury / 临床肝胆病杂志

The incidence rate of drug-induced liver injury （DILI） is increasing year by year with unknown mechanisms， and the treatment methods for DILI mainly include drugs， liver support systems， and liver transplantation， all of which have certain limitations. Therefore， the search for safer and more effective treatment methods has become a research hotspot at present. Studies have shown that mesenchymal stem cells and their exosomes can alleviate liver injury by reducing liver inflammation， promoting hepatocyte proliferation and regeneration， inhibiting the apoptosis of hepatocytes， improving oxidative stress， and regulating immunity. This article briefly reviews the role of mesenchymal stem cells and their exosomes in the treatment of DILI， so as to provide a reference for further research.

Effect of human umbilical cord mesenchymal stem cells in treatment of mice with liver fibrosis and its mechanism / 临床肝胆病杂志

ObjectiveTo investigate the effect of human umbilical cord mesenchymal stem cells （hUCMSCs） in the treatment of mice with liver fibrosis and its mechanism. MethodsA total of 18 specific pathogen-free C57BL/6 mice， aged 6 weeks， were selected and divided into control group （n=6）， carbon tetrachloride （CCl4） model group （CCl4 group， n=6）， and hUCMSCs treatment group （MSC group， n=6） using a random number table. The mice in the CCl4 group and the MSC group were given intraperitoneal injection of CCl4 solution to establish a mouse model of liver fibrosis， while those in the control group were injected with the same dose of corn oil， and the mice in the MSC group were injected with hUCMSCs via the caudal vein during the injection of CCl4. At the end of week 8， mouse serum was collected， and the mice were sacrificed to collect and fix the liver. Enzyme-linked immunosorbent assay was used to measure the levels of inflammatory factors； an automatic biochemical detector was used to measure liver function parameters； HE staining， Masson staining， Sirius Red staining， and α-SMA immunofluorescence assay were used to evaluate liver fibrosis. Hepatic stellate cells （HSCs） stimulated by TGF-β were co-cultured with hUCMSCs in the medium with or without chitinase-3 like-protein-1 （CHI3L1）， and Western blot was used to measure the expression levels of proteins. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the Dunnett’s t-test was used for further comparison between two groups. ResultsMasson staining and Sirius Red staining showed that the CCl4 group had a significantly higher degree of fibrosis than the control group （both P<0.05）， and the MSC group had significant alleviation of fibrosis compared with the CCl4 group （both P<0.05）. Compared with the control group， the CCl4 group had significant increases in the levels of interleukin-1β， interleukin-6 （IL-6）， aspartate aminotransferase （AST）， alanine aminotransferase （ALT）， and alkaline phosphatase （ALP） （all P<0.05）， and compared with the CCl4 group， the MSC group had significant reductions in the levels of IL-6， AST， ALT， and ALP （all P<0.05）. The CCl4 group had significantly higher expression levels of CHI3L1 and α-SMA than the control group and the MSC group （all P<0.05）. The cell culture experiment showed that the MSC+HSC group had a significantly higher expression level of Bax than the HSC group and the MSC+CHI3L1 group （both P<0.05）， suggesting that CHI3L1 reversed the pro-apoptotic effect of MSC on activated HSCs. ConclusionThis study shows that hUCMSCs can improve liver fibrosis in mice， possibly by inhibiting CHI3L1 to promote the apoptosis of HSCs.