MSC-derived exosomes protect auditory hair cells from neomycin-induced damage via autophagy regulation

BACKGROUND: Sensorineural hearing loss (SNHL) poses a major threat to both physical and mental health; however, there is still a lack of effective drugs to treat the disease. Recently, novel biological therapies, such as mesenchymal stem cells (MSCs) and their products, namely, exosomes, are showing promising therapeutic potential due to their low immunogenicity, few ethical concerns, and easy accessibility. Nevertheless, the precise mechanisms underlying the therapeutic effects of MSC-derived exosomes remain unclear. RESULTS: Exosomes derived from MSCs reduced hearing and hair cell loss caused by neomycin-induced damage in models in vivo and in vitro. In addition, MSC-derived exosomes modulated autophagy in hair cells to exert a protective effect. Mechanistically, exogenously administered exosomes were internalized by hair cells and subsequently upregulated endocytic gene expression and endosome formation, ultimately leading to autophagy activation. This increased autophagic activity promoted cell survival, decreased the mitochondrial oxidative stress level and the apoptosis rate in hair cells, and ameliorated neomycin-induced ototoxicity. CONCLUSIONS: In summary, our findings reveal the otoprotective capacity of exogenous exosome-mediated autophagy activation in hair cells in an endocytosis-dependent manner, suggesting possibilities for deafness treatment.

Stability study of umbilical cord mesenchymal stem cells formulation in large-scale production / 药学学报

Umbilical cord mesenchymal stem cells (UC-MSCs) have been widely used in regenerative medicine, but there is limited research on the stability of UC-MSCs formulation during production. This study aims to assess the stability of the cell stock solution and intermediate product throughout the production process, as well as the final product following reconstitution, in order to offer guidance for the manufacturing process and serve as a reference for formulation reconstitution methods. Three batches of cell formulation were produced and stored under low temperature (2-8 ℃) and room temperature (20-26 ℃) during cell stock solution and intermediate product stages. The storage time intervals for cell stock solution were 0, 2, 4, and 6 h, while for intermediate products, the intervals were 0, 1, 2, and 3 h. The evaluation items included visual inspection, viable cell concentration, cell viability, cell surface markers, lymphocyte proliferation inhibition rate, and sterility. Additionally, dilution and culture stability studies were performed after reconstitution of the cell product. The reconstitution diluents included 0.9% sodium chloride injection, 0.9% sodium chloride injection + 1% human serum albumin, and 0.9% sodium chloride injection + 2% human serum albumin, with dilution ratios of 10-fold and 40-fold. The storage time intervals after dilution were 0, 1, 2, 3, and 4 h. The reconstitution culture media included DMEM medium, DMEM + 2% platelet lysate, 0.9% sodium chloride injection, and 0.9% sodium chloride injection + 1% human serum albumin, and the culture duration was 24 h. The evaluation items were viable cell concentration and cell viability. The results showed that the cell stock solution remained stable for up to 6 h under both low temperature (2-8 ℃) and room temperature (20-26 ℃) conditions, while the intermediate product remained stable for up to 3 h under the same conditions. After formulation reconstitution, using sodium chloride injection diluted with 1% or 2% human serum albumin maintained a viability of over 80% within 4 h. It was observed that different dilution factors had an impact on cell viability. After formulation reconstitution, cultivation in medium with 2% platelet lysate resulted in a cell viability of over 80% after 24 h. In conclusion, the stability of cell stock solution within 6 h and intermediate product within 3 h meets the requirements. The addition of 1% or 2% human serum albumin in the reconstitution diluent can better protect the post-reconstitution cell viability.

BMSCs promote M2 macrophage polarization to attenuate acute radiation-induced lung injury / 中国辐射卫生

Objective To investigate the therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) for radiation-induced lung injury (RILI) and the underlying mechanism. Methods Forty-five healthy adult male C57BL/6 mice were randomly divided into control, model, and BMSCs groups. The model and BMSCs groups received a single irradiation dose of 20 Gy to the chest, while the control group did not receive X-ray irradiation. For the BMSCs group, an injection of 1 × 106 BMSCs cells was administered via the tail vein within 6 h after irradiation. In the 5th week, the lung tissue was taken to observe pathological changes with HE staining; examine the expression of the inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) with immunohistochemical staining; observe the polarization of macrophages with immunofluorescence staining; and measure the expression of the epithelial-mesenchymal transition markers E-cadherin, N-cadherin, and vimentin proteins by Western blot. Results After radiation, the model group developed pulmonary vasodilation and congestion with septal thickening and inflammatory cell infiltration, and these changes were markedly reduced in the BMSCs group. The model group showed significantly down-regulated expression of IL-6 and TNF-α compared with significantly increased levels in the model group (P < 0.01, P < 0.05). Treatment with BMSCs significantly increased the polarization of lung macrophages towards the M2 type, while significantly decreasing the abnormally increased N-cadherin and vimentin levels in RILI mice (P < 0.05, P < 0.01). Conclusion BMSCs have therapeutic effects for RILI mice, which may be through promoting macrophage polarization from M1 to M2.

Application progress of mesenchymal stem cells in islet transplantation for type 1 diabetes mellitus / 器官移植

Islet transplantation is considered as one of the most effective approach for type 1 diabetes mellitus, although its efficacy is limited by several factors. Anoxia, stress and rejection occurring during the isolation, culturing and transplantation of islets may have impact on the outcome of the islet transplantation. Due to the biological properties such as anti-inflammation, angiogenetic promotion and immune regulation, mesenchymal stem cells (MSCs) are all the way focused by researchers. Additionally, exosome, a derivative of MSC, also plays an import role in regulating anoxia-induced oxidative stress modulation, angiogenetic promotion, and immune regulation. MSC-based islet transplantation may be a useful therapeutic tool in treating type 1 diabetes. Therefore, in this review, the potential effect of MSC prior and posterior to the operation of the islet transplantation, its clinical application as well as its limitations were reviewed, aiming to offer insights into the future application of islet transplantation in treating type 1 diabetes.

Isolation of bone marrow mesenchymal stem cells in transgenic pigs and co-culture with porcine islets / 器官移植

Objective To investigate the isolation and culture of porcine bone marrow mesenchymal stem cell (BMSC) with α-1, 3-galactosyltransferase (GGTA1) gene knockout (GTKO), GTKO/ human CD46 (hCD46) insertion and cytidine monopho-N-acetylneuraminic acid hydroxylase (CMAH)/GGTA1 gene knockout (Neu5GC/Gal), and the protective effect of co-culture with porcine islets on islet cells. Methods Bone marrow was extracted from different transgenic pigs modified with GTKO, GTKO/hCD46 and Neu5GC/Gal. Porcine BMSC were isolated by the whole bone marrow adherent method and then cultured. The morphology of BMSC was observed and the surface markers of BMSC were identified by flow cytometry. Meantime, the multi-directional differentiation induced by BMSC was observed, and the labeling and tracing of BMSC were realized by green fluorescent protein (GFP) transfection. The porcine BMSC transfected with GFP were co-cultured with porcine islet cells. Morphological changes of porcine islet cells were observed, and compared with those in the porcine islet cell alone culture group. Results BMSC derived from pigs were spindle-shaped in vitro, expressing biomarkers of CD29, CD44, CD73, CD90, CD105 and CD166 rather than CD34 and CD45. These cells were able to differentiate into adipocytes, osteoblasts and chondrocytes. Porcine BMSC with GFP transfection could be labeled and traced, which could be stably expressed in the daughter cells after cell division. Porcine BMSC exerted certain protective effect on islet cells. Conclusions GFP-labeled porcine BMSC modified with GTKO, GTKO/hCD46 and Neu5GC/Gal are successfully established, which exert certain protective effect upon islet cells.

Mesenchymal cells in rotator cuff repair - technique description and case reports / Células mesenquimais no reparo da rotura do manguito rotador - descrição de técnica e relato de casos

ABSTRACT Objective: To describe a protocol of obtention of mesenchymal stem cells and to report their use as a biological adjuvant in three patients undergoing arthroscopic rotator cuff repair. Methods: Case series of patients who underwent arthroscopic repair of isolated full-thickness supraspinatus tear using mesenchymal stem cells obtained from the bone marrow as a biological adjuvant. All patients were operated on at the same institution, by a surgeon with 13 years of experience. The cells were applied at the end of the procedure, at the tendon-bone interface, at an approximate concentration of 2,000,000 mesenchymal cells/mm3 and a total volume of 5 ml. Results: All patients improved with the procedure, with one excellent and two good results. All cases overcame the minimally important clinical difference. All cases reached tendon healing, without partial or complete re-tears. We observed no complications. Conclusion: Arthroscopic rotator cuff repair with added mesenchymal cells obtained from bone marrow and submitted to a cell expansion process led to good functional results and healing in all cases in the sample, with no complications. Level of Evidence IV, Case Series.

RESUMO Objetivo: Descrever o protocolo de obtenção de células mesenquimais e relatar seu uso como adjuvante biológico em três pacientes submetidos ao reparo artroscópico do manguito rotador. Métodos: Série de casos de pacientes submetidos ao reparo artroscópico de rotura transfixante do músculo supraespinal utilizando como adjuvante biológico células mesenquimais obtidas da medula óssea. Todos ospacientes foram operados na mesma instituição por um cirurgião com 13 anos de experiência. As células foram aplicadas ao final do procedimento, na interface do tendão com o osso, na concentração aproximada de 2 milhões de células mesenquimais/mm3 e volume total de 5 ml. Resultados: Todos os pacientes melhoraram após o procedimento, havendo um resultado excelente e dois bons. Todos superaram a diferença clínica minimamente importante. Em todos os casos ocorreu cicatrização tendínea, sem a presença de rerroturas parciais ou completas. Não observamos complicações. Conclusão: O reparo do manguito rotador artroscópico com adição de células mesenquimais obtidas da medula óssea e submetidas a processo de expansão celular levou a bons resultados funcionais e cicatrização, sem complicações, em todos os casos da amostra. Nível de Evidência IV, Série de Casos.

Avaliação dos efeitos modulatórios da hematopoese no envelhecimento: Papel das células tronco mesenquimais medulares / Evaluation of the modulatory effects of hematopoiesis during aging: Role of bone marrow mesenchymal stem cells

O envelhecimento é um processo fisiológico que traz consigo uma série de alterações no organismo que se estendem até o nível molecular. Diante disto, este é um processo complexo que afeta diversos tecidos, sendo um deles o hematopoético, local onde, através de interações da Célula Tronco Hematopoética (CTH) com o ambiente ao seu redor, incluindo a Célula Tronco Mesenquimal (CTM), ocorre a hematopoese. Embora já sejam descritas na literatura algumas alterações na medula óssea consequentes do envelhecimento, os mecanismos por trás de tais mudanças permanecem elusivas, principalmente no âmbito das interações celulares ocorrentes na medula óssea. Portanto, este trabalho buscou investigar como o envelhecimento afeta a regulação hematopoética no contexto de sua relação com as CTM medulares. Para esta pesquisa, foram utilizados camundongos machos isogênicos da linhagem C57BL/6, dividindoos em grupos conforme sua idade: jovens (3 ­ 5 meses) e idosos (18 ­ 19 meses). Foi realizada a caracterização do modelo através de aspectos físicos como consumo proteico, variação de peso, entre outros, seguido de avaliação bioquímica e hematológica. Adicionalmente, foram coletadas células medulares e, posteriormente, realizado o isolamento das CTMs. Para estudar a relação destas células com a hematopoese, foram realizados ensaios in vitro utilizando a linhagem celular leucêmica C1498 (TIB-49™, ATCC®) mantidas em contato com o sobrenadante das CTMs isoladas. Quanto aos parâmetros bioquímicos, os animais idosos apresentaram menores níveis de albumina, aspartato alanina transferase (ALT) e de triglicerídeos quando comparados aos animais jovens. Contrariamente, os animais idosos apresentaram um maior nível de colesterol. Na avaliação hematológica, foi constatado pelo hemograma que os animais idosos apresentaram valores comparáveis aos animais jovens, todavia, o mielograma mostrou menor celularidade geral, seguido de menor número de células da linhagem eritroide e maior número de precursores granulocíticos. Através da imunofenotipagem, foi revelado um maior número de CTHs e de precursores grânulosmonocíticos na medula de animais idosos quando comparado aos jovens, e uma menor frequência de progenitores linfoides. Na imunofenotipagem de sangue periférico de animais idosos houve uma redução no número de linfócitos B e de eritrócitos, e aumento na população de células natural killers. Na imunofenotipagem de CTMs, o marcador CD73 apresentou menor expressão nos animais idosos. Avaliando o secretoma destas células estromais, foram encontrados no sobrenadante de CTMs de animais idosos aumentos significativos nas concentrações de CXCL12 e SCF e redução de IL-11. No âmbito molecular, as CTMs de animais idosos apresentaram aumento na expressão de Akt1, Nos e Ppar-γ, e redução na expressão de Csf3 e Cdh2. Adicionalmente, quando comparado a ação das CTMs de animais idosos em relação as CTMs de animais jovens, observou-se que CTMs de animais idosos foram capazes de aumentar a expressão de Sox2, Pou5f1 e Nanog e diminuir a expressão de Cdkn1a de células da linhagem C1498. O sobrenadante de CTMs de animais idosos também resultou na maior proliferação e migração de células da linhagem C1498. Portanto, levando em consideração a importância das CTMs sobre a regulação do sistema hematopoético, pode-se concluir que, no envelhecimento, as CTMs criam um ambiente propício para a proliferação celular no qual a manutenção da pluripotência é estimulada, o que pode acarretar em uma desregulação do sítio hematopoético quando habitado por células malignas

Aging is a physiological process in which occurs a series of alterations in an organism that extend to a molecular level. It is a complex process that affects various tissues, one of them being the bone marrow, wherethrough the interactions of the hematopoietic stem cell (CTH) with its surrounding environment, including with the mesenchymal stem cell (CTM), hematopoiesis takes place. Although some aging-associated alterations in the bone marrow can be found described in the literature, the mechanisms behind said changes remain elusive, especially when regarding the cellular interactions present inside the bone marrow. Therefore, this research aimed to investigate how aging affects the regulation of hematopoiesis in the context of its interactions with bone marrow-derived CTMs. For this investigation, male isogenic C57BL/6 mice were used as animal models. These were separated in two groups according to their age: young (3 ­ 5 months) and aged (18 ­ 19 months). The animal models were characterized by their physical properties such as protein intake and weight variation, followed by biochemical and hematological evaluation. Bone marrow cells were obtained and identified through immunophenotyping, thus isolating different cell populations, including the CTMs. To study the relationship between these cells and hematopoiesis, in vitro assays were conducted utilizing the leukemic cell lineage C1498 (TIB-49™, ATCC®) maintained in contact with the supernatant of isolated CTMs. By their biochemical profile, aged mice showed lower levels of albumin, alanine-aspartate transferase (ALT) and triglycerides compared to the young group. In contrast, aged mice had a higher cholesterol level. Hematological evaluation by total blood count showed similar results between the two groups, however, the myelogram revealed that the aged animals had lower cellularity, with less frequent cells from the erythroid lineage, with an increase in granulocytic precursors. Through immunophenotyping, it was also revealed that aged mice have higher numbers of hematopoietic stem cells, while also being noted a reduced population of lymphoid progenitors. An increase in the granulomonocytic progenitors was also found. Immunophenotyping peripheral blood cells of aged mice revealed reduced numbers of B lymphocytes and erythrocytes, and an increased natural killer cell population. Additionally, the cell surface marker CD73 was found to be less expressed in aged mice CTMs. The secretome of these stromal cells obtained from aged mice showed higher levels of CXCL12 and SCF, and lower levels of IL-11when compared to the young counterparts. At a molecular level, CTMs obtained from aged mice expressed more Akt1, Nos and Ppar-γ, while the expression of Csf3 and Cdh2 was reduced. Additionally, when comparing the effects of aged mice CTMs with young mice CTMs, it was observed that the first expressed were capable of increasing the expression of Sox2, Pou5f1 and Nanog, while decreasing Cdkn1a expression in the C1498 cell lineage. The supernatant obtained from aged mice also favored the proliferation and cell migration of the C1498 cell line. Thus, considering the importance that CTMs have over the hematopoietic system, we can conclude that, in aging, CTMs create a special environment which favors cell proliferation and maintenance of pluripotency, which can result in a dysregulation of the hematopoietic tissue when malignant cells are present

Mesenchymal stem cells modulate IL-17 and IL-9 production induced by Th17-inducing cytokine conditions in autoimmune arthritis: an explorative analysis

Abstract Background The importance of proinflammatory T-cells and their cytokine production in patients with autoimmune arthritis has been widely described. Due to their immunomodulatory properties, mesenchymal stem cells (MSCs) have come into focus as a potential therapeutic concept. The aim of this study was to investigate the influence of MSCs on the phenotype, cytokine profile, and functionality of naive and non-naive CD4+ T-cells from healthy donors (HD) and patients with autoimmune arthritis under Th17-cytokine polarizing conditions in an explorative way using a transwell system prohibiting any cell-cell-contact. Methods Magnetically isolated naive and non-naive CD4+ T-cells were stimulated under Th17-polarizing proinflammatory cytokine conditions in presence and absence of bone marrow derived mesenchymal stromal cells (MSCs). After an incubation period of 6 days, the proportions of the T-cell subpopulations TEMRA (CD45RA+CD27−), memory (CD45RA−CD27+), effector (CD45RA−CD27−) and naive cells (CD45RA+CD27+) were determined. Quantitative immunofluorescence intensity was used as a measure for IL-9, IL-17 and IFN-γ production in each subpopulation. Results In isolated naive CD4+ T-cells from HD and patients, MSCs suppressed the differentiation of naive towards an effector phenotype while memory and naive cells showed higher percentages in culture with MSCs. In patients, MSCs significantly decreased the proportion of IL-9 and IL-17 producing effector T-cells. MSCs also reduced IFN-γ production in the naive and memory phenotype from HD. Conclusions The results of the study indicate significant immunomodulatory properties of MSCs, as under Th17-polarizing conditions MSCs are still able to control T-cell differentiation and proinflammatory cytokine production in both HD and patients with autoimmune arthritis.

Glucose and serum deprivation under hypoxia treatment inducing oxidative stress and apoptosis in rat bone marrow mesenchymal stem cells through inhibition of Nrf2 signaling pathway / 解剖学报

Objective To investigate the effects of glucose and serum deprivation under hypoxia(GSDH)treatment on oxidative stress and apoptosis in rat bone marrow mesenchymal stem cells (BMSCs), so to provide an experimental support for improving the therapeutic efficacy of BMSCs. Methods The cell injury model was established by hypoxia (1% O

Extracellular vesicle-carried GTF2I from mesenchymal stem cells promotes the expression of tumor-suppressive FAT1 and inhibits stemness maintenance in thyroid carcinoma / 医学前沿

Through bioinformatics predictions, we identified that GTF2I and FAT1 were downregulated in thyroid carcinoma (TC). Further, Pearson's correlation coefficient revealed a positive correlation between GTF2I expression and FAT1 expression. Therefore, we selected them for this present study, where the effects of bone marrow mesenchymal stem cell-derived EVs (BMSDs-EVs) enriched with GTF2I were evaluated on the epithelial-to-mesenchymal transition (EMT) and stemness maintenance in TC. The under-expression of GTF2I and FAT1 was validated in TC cell lines. Ectopically expressed GTF2I and FAT1 were found to augment malignant phenotypes of TC cells, EMT, and stemness maintenance. Mechanistic studies revealed that GTF2I bound to the promoter region of FAT1 and consequently upregulated its expression. MSC-EVs could shuttle GTF2I into TPC-1 cells, where GTF2I inhibited TC malignant phenotypes, EMT, and stemness maintenance by increasing the expression of FAT1 and facilitating the FAT1-mediated CDK4/FOXM1 downregulation. In vivo experiments confirmed that silencing of GTF2I accelerated tumor growth in nude mice. Taken together, our work suggests that GTF2I transferred by MSC-EVs confer antioncogenic effects through the FAT1/CDK4/FOXM1 axis and may be used as a promising biomarker for TC treatment.

Bone marrow mesenchymal stem cells exosome miR-126-3p targets CCR1 to inhibit the malignant proliferation and metastasis of non-small cell lung cancer cells / 西安交通大学学报(医学版)

【Objective】 To investigate the effects of miR-126-3p targeting chemokine receptor 1 (CCR1) in exosomes derived from bone marrow mesenchymal stem cells (BMSC) on the proliferation, migration, and invasion of lung cancer cells. 【Methods】 BMSC cells were cultured; exosomes were extracted and identified by the exosomal marker proteins CD63 and TSG101. After exosome culture of A549 cells for different durations (0, 24, 48, and 72 h), cell survival rate was detected by CCK-8, mRNA levels of miR-126-3p and CCR1 were detected by qRT-PCR, and cell migration and invasion abilities were detected by Transwell assay. The relative expressions of CCR1, epithelial cadherin (E-cad), neural cadherin (N-cadherin), and Vimentin were detected by Western blotting. 【Results】 Exosomes had round or oval cup-shaped structures with bright edges and dark middle, with a particle size distribution of about 152 nm, expressing CD63 and TSG101 proteins. The expression of miR-126-3p in exosomes was higher than that in A549 cells. The expression of miR-126-3p was low in A549 cells and that of CCR1 mRNA was high. However, after co-culture with exosomes, the expression of miR-126-3p in A549 cells was increased, while the expression of CCR1 was decreased. A549 cells were cocultured with exosomes for 0, 24, 48, and 72 h. The survival rate, migration and invasion abilities, CCR1 gene and protein expression levels, and N-cad and Vimentin protein expression levels of A549 cells decreased gradually with the extension of culture time. The level of miR-126-3p and the expression of E-cad protein increased gradually with the extension of culture time. 【Conclusion】 The co-culture of exosomes derived from bone marrow mesenchymal stem cells with A549 cells can increase the expression level of miR-126-3p, and miR-126-3p can reduce the proliferation, migration, and invasion of A549 cells by targeting the inhibition of CCR1 expression.

Bone marrow mesenchymal stem cell-derived exosomes promote microglia/macrophage M2 polarization in acute cerebral ischemia rats and inhibit inflammatory response / 中国药科大学学报

@#The aim of the present study was to investigate the effects of exosomes derived from bone marrow mesenchymal stem cells (BMSCs) on the polarization of M1/M2 microglia/macrophages in rats with acute cerebral ischemia.Ultrahigh-speed centrifugation was employed to isolate and identify exosomes; a middle cerebral artery occlusion (MCAO) model was prepared in rats using the intraluminal filament technique; Longa scoring and corner tests were used to evaluate the neurological function of rats; 2, 3, 5-triphenyltetrazole chloride (TTC) staining was used to assess the infarct volume in rat brains; immunofluorescence double-labeling of CD16/32/Iba1 and CD206/Iba1 was performed to detect M1/M2 phenotypes of microglia/macrophages; RT-qPCR was employed to measure the mRNA expression of CD86, inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), arginase-1 (Arg-1), interleukin-10 (IL-10), and transforming growth factor beta (TGF-β) in the ischemic penumbra of rat brains.The experimental results showed that BMSC-Exos reduced the number of CD16/32+/Iba1+ positive cells in the ischemic penumbra (P < 0.01) while increasing the number of CD206+/Iba1+positive cells (P < 0.01), and decreased the mRNA expression of iNOS, CD86, and TNF-α, while increasing the mRNA expression of Arg-1, TGF-β, and IL-10 (P < 0.05 or P < 0.01).This research suggests that BMSC-Exos can regulate M1/M2 polarization of microglia/macrophages in rats with acute cerebral ischemia, alleviate neuroinflammation, and improve ischemic brain injury.

Efficacy of human umbilical cord mesenchymal stem cells via different transplantation approaches in treatment of rats with liver cirrhosis / 临床肝胆病杂志

ObjectiveTo investigate the therapeutic effect of the frozen and fresh preparations of human umbilical cord mesenchymal stem cells （hUC-MSC） on a rat model of liver cirrhosis after transplantation via the portal vein or the caudal vein. MethodsA total of 70 specific pathogen-free healthy male Sprague-Dawley rats were randomly divided into normal group （13 rats fed with ordinary tap water and rat food） and liver cirrhosis model group （57 rats given subcutaneous multi-point injection of mixed carbon tetrachloride/olive oil solution）. At week 8， the growth of rats was observed for both groups， and 3 rats were selected from each group for histopathological examination to confirm the formation of liver cirrhosis. A total of 50 rats were selected from the liver cirrhosis model and were divided into model group， portal vein group+fresh cell preparation group， portal vein+frozen cell preparation group， caudal vein+fresh cell preparation group， and caudal vein+frozen cell preparation group using a random number table， with 10 rats in each group. Fresh or frozen hUC-MSC were transplanted via the portal vein or the caudal vein， and after 4 weeks of administration， the different groups were compared in terms of the changes in liver function parameters and liver fibrosis degree. Continuous data were expressed as mean±standard deviation， and the independent-samples t test was used for comparison between two groups； a one-way analysis of variance was used for comparison between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsAt week 8 of modeling， the model group showed the formation of pseudolobules of different sizes in the liver and met the diagnostic criteria for liver cirrhosis， with significant increases in the levels of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， total bilirubin （TBil）， and alkaline phosphatase （ALP） compared with the normal group （all P<0.001）， suggesting that the rat model of liver cirrhosis was established successfully. There were significant differences in the levels of ALT， AST， TBil， and ALP between the five groups （F=232.00， 177.10， 112.30， 121.70， all P<0.001）. Further comparison between two groups showed that the model group had significantly higher levels of ALT， AST， TBil， and ALP than the normal group （all P<0.01）， and the portal vein group+fresh cell preparation group， the portal vein+frozen cell preparation group， the caudal vein+fresh cell preparation group， and the caudal vein+frozen cell preparation group had significantly lower levels of ALT， AST， TBil， and ALP than the model group （all P<0.01）. ConclusionThere are significant improvements in liver function and liver fibrosis degree in a rat model of liver cirrhosis at week 4 after the transplantation of hUC-MSC， and frozen or fresh cell preparation and different transplantation approaches have no significant influence on treatment outcome.

Comparison of Exosomes Derived from Fibroblasts and Mesenchymal Stem Cells for the Treatment of Acute Wound Healing / 中山大学学报(医学科学版)

ObjectiveTo compare the therapeutical effect of exosomes derived from fibroblasts and mesenchymal stem cells on acute wound healing. MethodsPrimary human dermal fibroblasts （hDF） were isolated， cultured and identified. Human bone marrow mesenchymal stem cell exosomes （hMSC-EXO） and hDF exosomes （hDF-EXO） were extracted by ultracentrifuga tion. After 24 h of coincubation with hDF-EXO or hMSC-EXO， hDFs proliferation and migratory capacity were evaluated by cell counting kit-8 （CCK8） assay and scratch test. Full-thickness cutaneous wounds were created on 8-week-old female C57BL/6 mice， and topically applied with PBS （control）， hDF-EXO or hMSC-EXO. Wounds were measured at day 0， 2， 4， 7， and the uptake of exosomes in wound was observed at day 1. Quantitative PCR （qPCR） analysis was performed to detect the mRNA expression levels of TNF-α， IL-6， IL-1β， IL-10 in wound at day 1. HE staining was conducted to analyze the histological structure of wounds at day 7， while immunofluorescence staining was used to examine expression of PDGFR-α、α-SMA、Ki67. ResultshDF exhibited certain fibrolast-like characteristics with respect to expression of cell surface markers and specific proteins. hDF-EXO and hMSC-EXO presented exosomal morphology， size， and markers， and both concentrations were not statistically different （P>0.05）； CCK8 assay showed that both exosomes promoted hDF cell viability， compared with the negative control （P<0.01）， and hDF-EXO group had greater cell viability than hMSC-EXO group （P<0.01）. Scratch test indicated that hDF-EXO induced a significant increase in scratch healing rate versus the negative control （P<0.01）， hMSC-EXO （P<0.05）. In vivo experiments showed wound tissues took up exosomes at day 1. qPCR detected TNF-α， IL-6， IL-1β expression levels in wound at day 1 were lower in exosomes group than in the control group， and were the lowest in hMSC-EXO group （all P<0.01）. Wound areas were measured smaller at day 7 in exosomes group than in the control group （all P<0.01） and hDF-EXO group had better closure than hMSC-EXO group （P<0.05）. HE staining revealed that compared with control group， scar， incomplete epidermis and few collagen deposition remained in the hMSC-EXO group， whereas hDF-EXO group showed re-epithelialization， continuous neo-epidermis and regenerated dermis. Immunofluorescence staining suggested that the number of fibroblasts， myofibroblasts， proliferating cells was higher in both exosomes group than that in the control group， especially the highest in hDF-EXO group. ConclusionOur study shows both exosomes accelerate wound healing， whereas hDF-EXO is more effective in promoting fibroblasts proliferation， migration， transition to myofibroblasts， and hMSC-EXO may play a role in inhibiting inflammatory reaction during early stage of wound healing.

Mechanism of regulatory effect of recombinant human HMGB1 on endothelial cell angiogenesis / 器官移植

Objective To unravel the possible mechanism of the role of recombinant human high mobility group box 1 (rhHMGB1) protein in regulating the angiogenesis of endothelial cells. Methods Endothelial cells were divided into the control group, bone marrow mesenchymal stem cells (MSC) supernatant group and rhHMGB1 group. The proliferation and survival of endothelial cells were detected by cell counting kit(CCK)-8 assay. The relative expression levels of vascular endothelial growth factor (VEGF), Yes-associated protein (YAP), CD31 and hypoxia inducible factor (HIF)-1α proteins were determined by Western blot. The relative expression levels of VEGF, YAP, CD31 and HIF-1α messenger RNA (mRNA) were detected by real-time fluorescent quantitative polymerase chain reaction (RT-qPCR). The migration ability of endothelial cells was assessed by Transwell chamber test. The localization of YAP was detected by immunofluorescence staining. Results Compared with the control group, the migration rate of endothelial cells was increased in the rhHMGB1 group (P < 0.05), and the cell migration rate was enhanced over time. Compared with the control group, the relative expression levels of VEGF and p-YAP proteins were up-regulated in the MSC supernatant group, and the differences were statistically significant (both P < 0.05). Compared with the control group, the relative expression levels of VEGF and HIF-1α proteins, VEGF and CD31 mRNA and YAP and p-YAP proteins were up-regulated, and YAP/p-YAP ratio was increased in the rhHMGB1 group, and the differences were statistically significant (all P < 0.05). Compared with the MSC supernatant group, the relative expression levels of CD31 mRNA and YAP protein were up-regulated, and the YAP/p-YAP ratio was increased in the rhHMGB1 group, and the differences were statistically significant (all P < 0.05). Conclusions Exogenous high-concentration rhHMGB1 may promote the migration ability of endothelial cells and up-regulate the expression levels of angiogenesis-related proteins by regulating the recruitment of YAP to the nucleus.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles enhance the regenerative capability of fibrotic liver / 器官移植

Objective To investigate the role of human umbilical cord mesenchymal stem cell-derived extracellular vesicle (hUC-MSC-EV) in the regeneration of fibrotic liver. Methods C57BL/6 mice were randomly divided into the 70% normal liver resection group (Oil+PHx group), 70% liver fibrosis resection group (CCl4+PHx group) and 70% liver fibrosis resection+mesenchymal stem cell-derived extracellular vesicle (MSC-EV) treatment group (CCl4+PHx+MSC-EV group), with 8 mice in each group. LX-2 cell lines were assigned into the phosphate buffer solution (PBS) group, transforming growth factor (TGF)-β group and TGF-β+MSC-EV group. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in mice after partial liver resection were detected in each group. The expression levels of liver fibrosis and proliferation-related parameters were analyzed in each group. The messenger RNA (mRNA) expression levels of epidermal growth factor (EGF), fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) in LX-2 cells were detected in each group, and their effects on HGF expression in mouse liver were observed. Results Compared with the Oil+PHx group, the serum levels of AST, ALT and LDH were up-regulated, and the degree of fibrosis was more severe, the positive area of Sirius red and α-smooth muscle actin (α-SMA) staining was larger, and the expression level of α-SMA protein was up-regulated in the CCl4+PHx group. Compared with the CCl4+PHx group, the serum levels of AST, ALT and LDH were decreased, the degree of fibrosis was slighter, the positive area of Sirius red and α-SMA staining was decreased, and the expression level of α-SMA protein was down-regulated in the CCl4+PHx+MSC-EV group, and the differences were statistically significant (all P < 0.05). Compared with the Oil+PHx group, the protein expression levels of Ki67 and proliferating cell nuclear antigen (PCNA) were lower in the CCl4+PHx group. Compared with the CCl4+PHx group, the protein expression levels of Ki67 and PCNA were increased in the CCl4+PHx+MSC-EV group, and the differences were statistically significant (all P < 0.05). Compared with the PBS group, the expression level of CollagenⅠ mRNA in LX-2 cells was increased, the expression level of α-SMA protein was up-regulated and the expression level of HGF protein was decreased in the TGF-β group. Compared with the TGF-β group, the expression level of CollagenⅠ mRNA in LX-2 cells was decreased, the expression levels of HGF mRNA and protein were increased, and the expression level of α-SMA protein was decreased in the TGF-β+MSC-EV group, the differences were statistically significant (all P < 0.05). The expression level of HGF protein in the CCl4+PHx group was lower than that in the Oil+PHx group, whereas the difference was not statistically significant (P > 0.05). The expression level of HGF protein in the CCl4+PHx+MSC-EV group was higher than that in the CCl4+PHx group, and the difference was statistically significant (P < 0.05). Conclusions The regenerative capacity of fibrotic liver is weaker than that of normal liver. hUC-MSC-EV may alleviate liver fibrosis and improve liver regeneration by promoting HGF secretion from actived hepatic stellate cells and effectively enhancing the regenerative capacity of fibrotic liver.

Protective role and mechanism of human umbilical cord mesenchymal stem cell-derived exosome in renal ischemia-reperfusion injury / 器官移植

Objective To investigate the protective effect of human umbilical cord mesenchymal stem cell-derived exosome (hucMSC-Exo) on renal ischemia-reperfusion injury (IRI), and to clarify the critical role and regulating mechanism of transient receptor potential canonical (TRPC) 6/poly adenosine-diphosphate-ribose polymerase (PARP) 1 signaling pathway during this process. Methods The hucMSC-Exo was extracted by ultracentrifugation, and identified by transmission electron microscope (TEM), nanoparticle tracing analysis and Western blot. SD rats were randomly divided into the sham operation group (group S), sham operation+TRPC6 inhibitor SKF96365 group (group SS), renal IRI group (group IRI), exosome treatment group (group EXO) and exosome +TRPC6 inhibitor SKF96365 group (group ES), with 6 rats in each group. Serum creatinine and blood urea nitrogen levels were detected. Pathological changes of renal tissues were observed by hematoxylin-eosin (HE) staining and Paller score was calculated. The expression levels of key molecules of necroptosis in rat renal tissues, including receptor-interacting protein kinase (RIPK)1, RIPK3 and mixed-lineage kinase domain-like protein (MLKL), TRPC6 and PARP1, were detected by Western blot. Results Typical saucer-like structure was observed under TEM. Nanoparticle tracing analysis showed that the average diameter of the extracted substance was 125.9 nm. Western blot revealed that the surface markers of CD9, CD63 and CD81 were positively expressed, confirmed that the extracted substance was exosome. Compared with group S, the serum creatinine and blood urea nitrogen levels were up-regulated, the pathological damage of renal tissues was worsened, Paller score was elevated, the relative expression levels of TRPC6 and PARP1 proteins were down-regulated, and the relative expression levels of RIPK1, RIPK3 and MLKL proteins were up-regulated in group IRI (all P < 0.05). Compared with group IRI, the serum creatinine and blood urea nitrogen levels were down-regulated, the pathological damage of renal tissues was mitigated, Paller score was decreased, the relative expression levels of TRPC6 and PARP1 proteins were up-regulated, and the relative expression levels of RIPK1, RIPK3 and MLKL proteins were down-regulated in group EXO (all P < 0.05). Compared with group EXO, the serum creatinine and blood urea nitrogen levels were up-regulated, the pathological damage of renal tissues was aggravated, Paller score was increased, the relative expression levels of TRPC6 and PARP1 proteins were down-regulated, and the relative expression levels of RIPK1, RIPK3 and MLKL proteins were up-regulated in group ES (all P < 0.05). Conclusions hucMSC-Exo may alleviate the necroptosis induced by renal IRI in rat models, which is related to the activation of TRPC6/PARP1 signaling pathway.

Prevention and treatment of chronic graft-versus-host disease by mesenchymal stem cells: advances and challenges / 器官移植

Chronic graft-versus-host disease (cGVHD) is the main complication after allogeneic hematopoietic stem cell transplantation, which is also the major cause of non-relapse -related death. Due to its complex pathophysiological process, the response rate of conventional glucocorticoids combined with immunosuppressants is less than 50%. Second-line therapy should be given for patients with glucocorticoid-resistant cGVHD. Nevertheless, no consensus has been reached on current second-line therapy and the therapeutic effect is relatively poor. Mesenchymal stem cell (MSC) is one of the most common adult stem cells. Due to multi-dimensional and multi-target immune regulating function, MSC has been widely applied in the prevention and treatment of cGVHD. In addition, accumulated studies have confirmed the safety and efficacy of MSC in the treatment of cGVHD, which is expected to become a novel strategy for the prevention and management of cGVHD. In this article, research progress, mechanism and existing problems of prevention and treatment of cGVHD by MSC were reviewed, aiming to provide novel ideas for optimizing therapeutic regimens of MSC and enhancing the prevention and treatment effect of cGVHD in subsequent research.

Current status and reflections on stem cell transplantation in the treatment of testicular aging / 器官移植

Testicular aging is mainly characterized by a gradual decline in the capability of testosterone synthesis and spermatogenesis, which not only affects male fertility, but also correlates with aging-related chronic diseases intimately. Therefore, delaying testicular aging plays a significant role in improving the health and quality of life of middle-aged and elderly men. Stem cells are a cell group with potent self-renewal capability and multi-directional differentiation potential. In recent years, the research of stem cells in basic and clinical application has been carried out in-depth, which has accelerated the development of cell therapy. Currently, stem cell transplantation has been employed to treat multiple diseases, which has captivated widespread attention in the field of aging and regenerative medicine. Stem cell transplantation has demonstrated promising prospects in the treatment of testicular aging. In this article, research profile and progress of stem cell transplantation in the treatment of testicular aging were reviewed, and bottleneck issues encountered in clinical translation and strategies for optimizing clinical efficacy were discussed, aiming to provide novel ideas for the research and development and clinical translation of stem cell therapy for testicular aging.

Improvement effect and mechanism of N-butylphthalide on inflammatory injury of bone marrow mesenchymal stem cells in rats / 中国药房

OBJECTIVE To study the improvement effect and possible mechanism of N-butylphthalide on inflammatory injury of bone marrow mesenchymal stem cells （BMSCs） in rats. METHODS BMSCs of rats were divided into control group， model group， N-butylphthalide low-concentration， medium-concentration and high-concentration groups （10， 20， 50 μmol/L）. BMSCs were cultured in vitro and lipopolysaccharide （the final concentration of 10 mg/L） was used to establish the inflammatory injury model. After the intervention of N-butylphthalide， the survival rate， apoptotic rate， the contents of tumor necrosis factor α （TNF- α）， interleukin 1β （IL-1β） and IL-6 in cell culture medium， the mRNA expression of nuclear factor-κB（NF-κB） p65， and the protein expressions of caspase-3， B-cell lymphoma 2 （Bcl-2）， Bcl-2 related X protein （Bax） and NF-κB p65 in cells were detected. RESULTS Compared with control group， the survival rate and protein expression of Bcl-2 were decreased significantly in model group （P＜0.05）； the apoptotic rate， contents of TNF-α， IL-1β and IL-6， the mRNA expression of NF-κB p65， and the protein expressions of caspase-3， Bax and NF-κB p65 were increased significantly （P＜0.05）. Compared with model group， above indexes were significantly reversed in all concentration groups of N-butylphthalide （P＜0.05）， in concentration-dependent manner. CONCLUSIONS N-butylphthalide can ameliorate the inflammatory injury of BMSCs induced by lipopolysaccharide， and its mechanism may be related to the inhibition of NF-κB signaling pathway.