Multiple strategies enhance the efficacy of MSC-Exos transplantation for spinal cord injury.

Spinal cord injury (SCI) is a relatively common and lethal dangerous disease of the central nervous system, for which there is a lack of effective clinical treatments. It has been found that mesenchymal stem cell-derived exosomes (MSC-Exos) play a key role in alleviating SCI through mechanisms such as regulating the microenvironment, promoting angiogenesis, and facilitating axonal regeneration. However, the drawbacks of natural exosomes, such as low yield, weak activity, and low targeting ability, limit their clinical applications. In recent years, MSCs-Exos have gradually become a research hotspot for treating SCI through miRNA modulation, combined hydrogel, and preculture. In addition, exosomes as good biocompatible drugs, nucleic acid, and other delivery carriers have shown a broad application prospect in treating SCI. This article summarizes the pathogenesis of SCI and the research progress of MSC-Exos in the treatment of SCI in recent years, and provides a systematic review of the mechanisms of MSC exosomes and their combination with different modalities in the treatment of SCI.

Mesenchymal stem cell therapy for liver fibrosis need "partner": Results based on a meta-analysis of preclinical studies.

BACKGROUND: The efficacy of mesenchymal stem cells (MSCs) in treating liver fibrosis has been demonstrated in several clinical studies. However, their low survival and liver implantation rates remain problematic. In recent years, a large number of studies in animal models of liver fibrosis have shown that MSCs combined with drugs can improve the efficacy of MSCs in the treatment of liver fibrosis alone and inhibit its progression to end-stage liver disease. This has inspired new ways of thinking about treating liver fibrosis. AIM: To investigate the effectiveness and mechanisms of MSCs combined with drugs in treating liver fibrosis. METHODS: Data sources included four electronic databases and were constructed until January 2024. The subjects, interventions, comparators, outcomes, and study design principle were used to screen the literature, and the quality of the literature was evaluated to assess the risk of bias. Relevant randomised controlled trials were selected, and the final 13 studies were included in the final study. RESULTS: A total of 13 studies were included after screening. Pooled analysis showed that MSCs combined with drug therapy significantly improved liver function, promoted the repair of damaged liver tissues, reduced the level of liver fibrosis-related indexes, and effectively ameliorated hepatic fibrosis by modulating the hepatic inflammatory microenvironment, promoting the homing of MSCs, and regulating the relevant signaling pathways, and the treatment efficacy was superior to MSCs alone. However, the combined treatment statistics showed no ame-lioration in serum albumin levels (standardized mean difference = 0.77, 95% confidence interval: -0.13 to 1.68, P = 0.09). CONCLUSION: In conclusion, MSCs combined with drugs for treating liver fibrosis effectively make up for the shortcomings of MSCs in their therapeutic effects. However, due to the different drugs, the treatment mechanism and effect also differ. Therefore, more randomized controlled trials are needed to compare the therapeutic efficacy of different drugs in combination with MSCs, aiming to select the "best companion" of MSCs in treating hepatic fibrosis.

Single and combined strategies for mesenchymal stem cell exosomes alleviate liver fibrosis: a systematic review and meta-analysis of preclinical animal models.

Background: The efficacy of mesenchymal stem cells (MSCs) in treating liver fibrosis has been supported by various clinical studies. However, stem cell transplantation is limited in clinical application due to its low survival rate, low liver implantation rate, and possible carcinogenicity. Recently, there has been increasing interest in the use of MSC-exos due to their widespread availability, low immunogenicity, and non-carcinogenic properties. Numerous studies have demonstrated the potential of MSC-exos in treating liver fibrosis and preventing progression to end-stage liver disease. Objective: This study aimed to systematically investigate the efficacy of MSC-exos single administration in the treatment of hepatic fibrosis and the combined advantages of MSC-exos in combination with drug therapy (MSC-exos-drugs). Methods: Data sources included PubMed, Web of Science, Embase, and the Cochrane Library, which were built up to January 2024. The population, intervention, comparison, outcomes, and study design (PICOS) principle was used to screen the literature, and the quality of the literature was evaluated to assess the risk of bias. Finally, the data from each study's outcome indicators were extracted for a combined analysis. Results: After screening, a total of 18 papers (19 studies) were included, of which 12 involved MSC-exos single administration for the treatment of liver fibrosis and 6 involved MSC-exos-drugs for the treatment of liver fibrosis. Pooled analysis revealed that MSC-exos significantly improved liver function, promoted the repair of damaged liver tissue, and slowed the progression of hepatic fibrosis and that MSC-exos-drugs were more efficacious than MSC-exos single administration. Subgroup analyses revealed that the use of AD-MSC-exos resulted in more consistent and significant efficacy when MSC-exos was used to treat hepatic fibrosis. For MSC-exos-drugs, a more stable end result is obtained by kit extraction. Similarly, infusion through the abdominal cavity is more effective. Conclusion: The results suggest that MSC-exos can effectively treat liver fibrosis and that MSC-exos-drugs are more effective than MSC-exos single administration. Although the results of the subgroup analyses provide recommendations for clinical treatment, a large number of high-quality experimental validations are still needed. Systematic Review Registration: CRD42024516199.

Effectiveness and mechanisms of mesenchymal stem cell therapy in preclinical animal models of hepatic fibrosis: a systematic review and meta-analysis.

Background: Liver damage due to long-term viral infection, alcohol consumption, autoimmune decline, and other factors could lead to the gradual development of liver fibrosis. Unfortunately, until now, there has been no effective treatment for liver fibrosis. Mesenchymal stem cells, as a promising new therapy for liver fibrosis, can slow the progression of fibrosis by migrating to the site of liver injury and by altering the microenvironment of the fibrotic area. Aim: By including all relevant studies to date to comprehensively assess the efficacy of mesenchymal stem cells for the treatment of hepatic fibrosis and to explore considerations for clinical translation and therapeutic mechanisms. Methods: Data sources included PubMed, Web of Science, Embase, and Cochrane Library, and were constructed until October 2023. Data for each study outcome indicator were extracted for comprehensive analysis. Results: The overall meta-analysis showed that mesenchymal stem cells significantly improved liver function. Moreover, it inhibited the expression level of transforming growth factor-ß [SMD = 4.21, 95% CI (3.02,5.40)], which in turn silenced hepatic stellate cells and significantly reduced the area of liver fibrosis [SMD = 3.61, 95% CI (1.41,5.81)]. Conclusion: Several outcome indicators suggest that mesenchymal stem cells therapy is relatively reliable in the treatment of liver fibrosis. The therapeutic effect is cell dose-dependent over a range of doses, but not more effective at higher doses. Bone-marrow derived mesenchymal stem cells were more effective in treating liver fibrosis than mesenchymal stem cells from other sources. Systematic Review Registration: Identifier CRD42022354768.

Bone marrow mesenchymal stem cells-derived exosomal miR-145-5p reduced non-small cell lung cancer cell progression by targeting SOX9.

BACKGROUND: The role of miR-145-5p in non-small cell lung cancer (NSCLC) has been studied, however, the regulation of hBMSCs-derived exosomes (Exo) transmitted miR-145-5p in NSCLC was still unknown. This study aimed to investigate the role of hBMSCs-derived exosomes (Exo) in the progression of NSCLC. METHODS: The Exo was extracted from hBMSCs and added to A549 and H1299 cell culture, followed by the detection of cell proliferation, migration, and invasion. The correlation between the expression of miR-145-5p and SOX9, as well as their binding relationship was determined by correlation analysis, luciferase gene reporter assay and RNA pull-down assays. The in vivo animal model was established to further verify the impact of hBMSCs-Exo. RESULTS: It showed that miR-145-5p was downregulated and SOX9 was upregulated in NSCLC tissues. HBMSCs-derived Exo, and hBMSCs-Exo with overexpression of miR-145-5p could inhibit cell proliferation, migration, and invasion of both A549 and H1299 cells, and prevent against tumor progression in vivo. MiR-145-5p and SOX9 were found to be able to bind to each other, and a negative correlation were observed between the expression of them in NSCLC tissues. Furthermore, inhibition of SOX9 could reversed the suppressed role of miR-145-5p in vitro and in vivo. CONCLUSION: Therefore, HBMSCs-Exo effectively transmitted miR-145-5p, leading to the suppression of malignant development in NSCLC through the regulation of SOX9.

Progress of mesenchymal stem cells (MSCs) & MSC-Exosomes combined with drugs intervention in liver fibrosis.

Liver fibrosis is an intrahepatic chronic damage repair response caused by various reasons such as alcoholic liver, fatty liver, viral hepatitis, autoimmune diseases, etc., and is closely related to the progression of liver disease. Currently, the mechanisms of liver fibrosis and its treatment are hot research topics in the field of liver disease remedy. Mesenchymal stem cells (MSCs) are a class of adult stem cells with self-renewal and multidirectional differentiation potential, which can ameliorate fibrosis through hepatic-directed differentiation, paracrine effects, and immunomodulation. However, the low inner-liver colonization rate, low survival rate, and short duration of intervention after stem cell transplantation have limited their wide clinical application. With the intensive research on liver fibrosis worldwide, it has been found that MSCs and MSCs-derived exosomes combined with drugs have shown better intervention efficiency than utilization of MSCs alone in many animal models of liver fibrosis. In this paper, we review the interventional effects and mechanisms of mesenchymal stem cells and their exosomes combined with drugs to alleviate hepatic fibrosis in vivo in animal models in recent years, which will provide new ideas to improve the efficacy of mesenchymal stem cells and their exosomes in treating hepatic fibrosis in the clinic.

Efficacy and safety of mesenchymal stem cells therapy in COVID-19 patients: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has become a serious public health issue. In COVID-19 patients, the elevated levels of inflammatory cytokines lead to the manifestation of COVID-19 symptoms, such as lung tissue edema, lung diffusion dysfunction, acute respiratory distress syndrome (ARDS), secondary infection, and ultimately mortality. Mesenchymal stem cells (MSCs) exhibit anti-inflammatory and immunomodulatory properties, thus providing a potential treatment option for COVID-19. The number of clinical trials of MSCs for COVID-19 has been rising. However, the treatment protocols and therapeutic effects of MSCs for COVID-19 patients are inconsistent. This meta-analysis was performed to systematically determine the safety and efficacy of MSC infusion in COVID-19 patients. METHODS: We conducted a comprehensive literature search from PubMed/Medline, Web of Science, EMBASE, and Cochrane Library up to 22 November 2023 to screen for eligible randomized controlled trials. Inclusion and exclusion criteria for searched literature were formulated according to the PICOS principle, followed by the use of literature quality assessment tools to assess the risk of bias. Finally, outcome measurements including therapeutic efficacy, clinical symptoms, and adverse events of each study were extracted for statistical analysis. RESULTS: A total of 14 randomized controlled trials were collected. The results of enrolled studies demonstrated that patients with COVID-19 pneumonia who received MSC inoculation showed a decreased mortality compared with counterparts who received conventional treatment (RR: 0.76; 95% CI [0.60, 0.96]; p = 0.02). Reciprocally, MSC inoculation improved the clinical symptoms in patients (RR: 1.28; 95% CI [1.06, 1.55]; p = 0.009). In terms of immune biomarkers, MSC treatment inhibited inflammation responses in COVID-19 patients, as was indicated by the decreased levels of CRP and IL-6. Importantly, our results showed that no significant differences in the incidence of adverse reactions or serious adverse events were monitored in patients after MSC inoculation. CONCLUSION: This meta-analysis demonstrated that MSC inoculation is effective and safe in the treatment of patients with COVID-19 pneumonia. Without increasing the incidence of adverse events or serious adverse events, MSC treatment decreased patient mortality and inflammatory levels and improved the clinical symptoms in COVID-19 patients. However, large-cohort randomized controlled trials with expanded numbers of patients are required to further confirm our results.

MAPK14 as a key gene for regulating inflammatory response and macrophage M1 polarization induced by ferroptotic keratinocyte in psoriasis.

Psoriasis is a prevalent condition characterized by chronic inflammation, immune dysregulation, and genetic alterations, significantly impacting the well-being of affected individuals. Recently, a novel aspect of programmed cell death, ferroptosis, linked to iron metabolism, has come to light. This research endeavors to unveil novel diagnostic genes associated with ferroptosis in psoriasis, employing bioinformatic methods and experimental validation. Diverse analytical strategies, including "limma," Weighted Gene Co-expression Network Analysis (WGCNA), Least Absolute Shrinkage and Selection Operator (LASSO), Support Vector Machine Recursive Feature Elimination (SVM-RFE), and Random Forest (RF), were employed to pinpoint pivotal ferroptosis-related diagnostic genes (FRDGs) in the training datasets GSE30999, testing dataset GSE41662 and GSE14905. The discriminative potential of FRDGs in distinguishing between normal and psoriatic patients was gauged using Receiver Operating Characteristic (ROC) curves, while the functional pathways of FRDGs were scrutinized through Gene Set Enrichment Analysis (GSEA). Spearman correlation and ssGSEA analysis were applied to explore correlations between FRDGs and immune cell infiltration or oxidative stress-related pathways. The study identified six robust FRDGs - PPARD, MAPK14, PARP9, POR, CDCA3, and PDK4 - which collectively formed a model boasting an exceptional AUC value of 0.994. GSEA analysis uncovered their active involvement in psoriasis-related pathways, and substantial correlations with immune cells and oxidative stress were noted. In vivo, experiments confirmed the consistency of the six FRDGs in the psoriasis model with microarray results. In vitro, genetic knockdown or inhibition of MAPK14 using SW203580 in keratinocytes attenuated ferroptosis and reduced the expression of inflammatory cytokines. Furthermore, the study revealed that intercellular communication between keratinocytes and macrophages was augmented by ferroptotic keratinocytes, increased M1 polarization, and recruitment of macrophage was regulated by MAPK14. In summary, our findings unveil novel ferroptosis-related targets and enhance the understanding of inflammatory responses in psoriasis. Targeting MAPK14 signaling in keratinocytes emerges as a promising therapeutic approach for managing psoriasis.

3D Spheroids Facilitate Differentiation of Human Adipose-Derived Mesenchymal Stem Cells into Hepatocyte-Like Cells via p300-Mediated H3K56 Acetylation.

Hepatocyte-like cells (HLCs) that are differentiated from mesenchymal stem cells (MSCs) provide a valuable resource for drug screening and cell-based regeneration therapy. Differentiating HLCs into 3D spheroids enhances their phenotypes and functions. However, the molecular mechanisms underlying MSCs hepatogenic differentiation are not fully understood. In this study, we generated HLCs from human adipose-derived mesenchymal stem cells (hADMSCs) in both 2D and 3D cultures. We performed an acetyl-proteomics assay on the HLCs derived from both 2D and 3D differentiation and identified a differential change in H3K56 acetylation between the 2 differentiated cells. Our findings revealed that 3D differentiation activated ALB gene transcription by increasing the acetylation level of H3K56, thereby enhancing the phenotypes and functions of HLCs and further promoting their maturation. Notably, inhibiting p300 reduced the acetylation level of H3K56 during hepatogenic differentiation, leading to decreased phenotypes and functions of HLCs, whereas activation of p300 promoted hepatogenic differentiation, suggesting that p300 plays a critical role in this process. In summary, our study demonstrates a potential mechanism through which 3D spheroids differentiation facilitates hADMSCs differentiation into HLCs by promoting p300-mediated H3K56 acetylation, which could have significant clinical applications in liver regeneration and disease modeling.

Human Umbilical Cord Mesenchymal Stem Cells Improve the Status of Hypoxic/Ischemic Cerebral Palsy Rats by Downregulating NogoA/NgR/Rho Pathway.

Human umbilical cord mesenchymal stem cells (hUCMSC) have shown promising potential in ameliorating brain injury, but the mechanism is unclear. We explore the role of NogoA/NgR/Rho pathway in mediating hUCMSC to improve neurobehavioral status and alleviate brain injury in hypoxia/ischemia-induced CP (cerebral palsy) rat model in order to promote the clinical application of stem cell therapy in CP. The injury model of HT22 cells was established after 3 h hypoxia, and then co-cultured with hUCMSC. The rat model of CP was established by ligation of the left common carotid artery for 2.5 h. Subsequently, hUCMSC was administered via the tail vein once a week for a total of four times. The neurobehavioral status of CP rats was determined by behavioral experiment, and the pathological brain injury was determined by pathological staining method. The mRNA and protein expressions of NogoA, NgR, RhoA, Rac1, and CDC42 in brain tissues of rats in all groups and cell groups were detected by real-time quantitative polymerase chain reaction (RT-qPCR), Western blot, and immunofluorescence. The CP rats exhibited obvious motor function abnormalities and pathological damage. Compared with the control group, hUCMSC transplantation could significantly improve the neurobehavioral situation and attenuate brain pathological injury in CP rats. The relative expression of NogoA, NgR, RhoA mRNA, and protein in brain tissues of rats in the CP group was significantly higher than the rats in the sham and CP+hUCMSC group. The relative expression of Rac1, CDC42 mRNA, and protein in brain tissues of rats in the CP group was significantly lower than the rats in the sham and CP+hUCMSC group. The animal experiment results were consistent with the experimental trend of hypoxic injury of HT22 cells. This study confirmed that hUCMSC can efficiently improve neurobehavioral status and alleviate brain injury in hypoxia/ischemia-induced CP rat model and HT22 cell model through downregulating the NogoA/NgR/Rho pathway.

Efficacy and safety of mesenchymal stem cell therapy in liver cirrhosis: a systematic review and meta-analysis.

AIM: Although the efficacy and safety of mesenchymal stem cell therapy for liver cirrhosis have been demonstrated in several studies. Clinical cases of mesenchymal stem cell therapy for patients with liver cirrhosis are limited and these studies lack the consistency of treatment effects. This article aimed to systematically investigate the efficacy and safety of mesenchymal stem cells in the treatment of liver cirrhosis. METHOD: The data source included PubMed/Medline, Web of Science, EMBASE, and Cochrane Library, from inception to May 2023. Literature was screened by the PICOS principle, followed by literature quality evaluation to assess the risk of bias. Finally, the data from each study's outcome indicators were extracted for a combined analysis. Outcome indicators of the assessment included liver functions and adverse events. Statistical analysis was performed using Review Manager 5.4. RESULTS: A total of 11 clinical trials met the selection criteria. The pooled analysis' findings demonstrated that both primary and secondary indicators had improved. Compared to the control group, infusion of mesenchymal stem cells significantly increased ALB levels in 2 weeks, 1 month, 3 months, and 6 months, and significantly decreased MELD score in 1 month, 2 months, and 6 months, according to a subgroup analysis using a random-effects model. Additionally, the hepatic arterial injection favored improvements in MELD score and ALB levels. Importantly, none of the included studies indicated any severe adverse effects. CONCLUSION: The results showed that mesenchymal stem cell was effective and safe in the treatment of liver cirrhosis, improving liver function (such as a decrease in MELD score and an increase in ALB levels) in patients with liver cirrhosis and exerting protective effects on complications of liver cirrhosis and the incidence of hepatocellular carcinoma. Although the results of the subgroup analysis were informative for the selection of mesenchymal stem cells for clinical treatment, a large number of high-quality randomized controlled trials validations are still needed.

Thallium exposure induces changes in B and T cell generation in mice.

Thallium (Tl) is a high-priority toxic metal that poses a severe threat to human health. The toxicity characteristics induced by Tl have been partially discussed. However, the immunotoxic effects of Tl exposure have remained largely unexplored. Our findings demonstrated that 50 ppm of Tl exposure for one week induced severe weight loss in mice, which was accompanied by appetite suppression. Moreover, although Tl exposure did not induce significant pathological damage to skeletal muscle and bone, Tl inhibited the expression of B cell development-related genes in the bone marrow. Additionally, Tl exposure increased B cell apoptosis and reduced its generation in the bone marrow. Analysis of B cells in the blood indicated that the percentage of B-2 cells decreased significantly, whereas B-2 cell proportions in the spleen did not. The percentage of CD4+ T cells in the thymus increased significantly, and the proportion of CD8+ T cells did not. Furthermore, although the proportion of the total CD4+ and CD8+ T cells was not significantly altered in the blood and spleen, Tl exposure promoted the migration of naïve CD4+ T cells and recent thymic emigrants (RTEs) from the thymus to the spleen. These results suggest that Tl exposure can affect B and T cell generation and migration, which provides new evidence for Tl-induced immunotoxicity.

Efficacy and Safety of Stem Cell Therapy in Children With Autism Spectrum Disorders: A Systematic Review and Meta-Analysis.

Aim: There is insufficient evidence regarding the efficacy and safety of stem cell therapy for autism spectrum disorders. We performed the first meta-analysis of stem cell therapy for autism spectrum disorders in children to provide evidence for clinical rehabilitation. Methods: The data source includes PubMed/Medline, Web of Science, EMBASE, Cochrane Library and China Academic Journal, from inception to 24th JULY 2021. After sifting through the literature, the Cochrane tool was applied to assess the risk of bias. Finally, we extracted data from these studies and calculated pooled efficacy and safety. Results: 5 studies that met the inclusion criteria were included in current analysis. Meta-analysis was performed using rehabilitation therapy as the reference standard. Data showed that the Childhood Autism Rating Scale score of stem cell group was striking lower than the control group (WMD: -5.96; 95%CI [-8.87, -3.06]; p < 0.0001). The Clinical Global Impression score consolidated effect size RR = 1.01, 95%CI [0.87, 1.18], Z = 0.14 (p = 0.89), the effective rate for The Clinical Global Impression was 62% and 60% in the stem cell group and the control group, respectively. The occurrence events of adverse reactions in each group (RR = 1.55; 95%CI = 0.60 to 3.98; p = 0.36), there was no significant difference in the incidence of adverse reactions between the stem cell group and the control group. Conclusions: The results of this meta-analysis suggested that stem cell therapy for children with autism might be safe and effective. However, the evidence was compromised by the limitations in current study size, lacking standardized injection routes and doses of stem cells, as well as shortages in diagnostic tools and long period follow-up studies. Hence, it calls for more studies to systematically confirm the efficacy and safety of stem cell therapy for children with autism spectrum disorders.

Novel Thermosensitive Hydrogel Promotes Spinal Cord Repair by Regulating Mitochondrial Function.

The repair of spinal cord injury (SCI) is still a tough clinical challenge and needs innovative therapies. Mitochondrial function is significantly compromised after SCI and has emerged as an important factor causing neuronal apoptosis and hindering functional recovery. In this study, umbilical cord mesenchymal stem cells (UCMSC), which are promising seed cells for nerve regeneration, and basic fibroblast growth factor (bFGF) that have been demonstrated to have a variety of effects on neural regeneration were jointly immobilized in extracellular matrix (ECM) and heparin-poloxamer (HP) to create a polymer bioactive system that brings more hope and possibility for the treatment of SCI. Our results in vitro and in vivo showed that the UCMSC-bFGF-ECM-HP thermosensitive hydrogel has good therapeutic effects, mainly in reducing apoptosis and improving the mitochondrial function. It showed promising utility for the functional recovery of impaired mitochondrial function by promoting mitochondrial fusion, reducing pathological mitochondrial fragmentation, increasing mitochondrial energy supply, and improving the metabolism of MDA, LDH, and ROS. In addition, we uncovered a distinct molecular mechanism underlying the protective effects associated with activating p21-activated kinase 1 (PAK1) and mitochondrial sirtuin 4 (SIRT4) by the UCMSC-bFGF-ECM-HP hydrogel. The expansion of new insights into the molecular relationships between PAK1 and SIRT4, which links the mitochondrial function in SCI, can lay the foundation for future applications and help to provide promising interventions of stem-cell-based biological scaffold therapies and potential therapeutic targets for the clinical formulation of SCI treatment strategies.

Double-Gene Copromoting Expression Analysis in tPA/GH Transgenic Goat Mammary Epithelial Cells and Thrombolytic Activity of tPA In Vitro.

Human tissue-plasminogen activator (tPA) is a thrombolytic drug widely used in the treatment of stroke, pulmonary thrombosis, acute myocardial infarction, and other thrombotic diseases. The double genes cointegrated into the organisms and cells can produce a synergistic effect, which will improve the expression level of the target gene. However, the study of the integration of the GH and tPA genes to improve the expression level of tPA has not yet been reported. In order to elucidate this, we generated monoclonal goat mammary epithelial cell lines with tPA/GH double-gene integration and analyzed the tPA expression level in single- and double-gene integrated cells. We selected the mammary gland-specific expressing vectors BLC14/tPA and BLC14/GH with the ß-lactoglobulin gene as a regulatory sequence in our previous research. The tPA and GH genes were electronically cotransfected into goat mammary epithelial cells. Resistant cell lines were screened by G418, and transgenic monoclonal cell lines were confirmed by PCR. The tPA expression was induced by prolactin and detected in the cell induction solution after 48 h by ELISA and Western blotting. We detected the tPA biological activity in vitro by fibrin agarose plate assay (FAPA). The results showed that a total of 207 resistant monoclonal cells were obtained, including 126 cell lines with tPA monogenic integration and 51 cell lines with tPA/GH double-gene integration. The rate of double-gene integration was 24.6% (51/207). A total of 48 cells expressed tPA, of which 25.3% (19/75) cells expressed single gene, and 56.9% (29/51) cells expressed double genes. The concentration of tPA in single-gene-expressing cells was 8.0-64.0 µg/mL, and the tPA level in double-gene-expressing cells was significantly higher (200-7200 µg/mL). In addition, the tPA had a relatively strong in vitro thrombolytic activity determined by FAPA. The results showed that goat mammary epithelial cell lines with tPA/GH gene integration were successfully established by electrotransfection, and the expression level of tPA in double-gene integrated cell lines was significantly increased. This study provided a new way for the preparation of a transgenic goat and other animal with high tPA expression by somatic cell nuclear transfer. The findings also laid a foundation for efficient production of pharmaceutical proteins in transgenic animal mammary gland bioreactors in the future.

Determination of Hepatic Iron Deposition in Drug-Induced Liver Fibrosis in Rats by Confocal Micro-XRF Spectrometry.

Liver fibrosis is the intermediate process and inevitable stage of the development of chronic liver disease into cirrhosis. Reducing the degree of liver fibrosis plays an extremely important role in treating chronic liver disease and preventing liver cirrhosis and liver cancer. The formation of liver fibrosis is affected by iron deposition to a certain extent, and excessive iron deposition further induces liver cirrhosis and liver cancer. Herein, confocal microbeam X-ray fluorescence (µ-XRF) was used to determine the intensity and biodistribution of iron deposition at different time points in the process of liver fibrosis induced by thioacetamide (TAA) in rats. To our best knowledge, this is the first study using confocal µ-XRF to analyze hepatic iron deposition in hepatic fibrosis. The results showed that there are minor and trace elements such as iron, potassium, and zinc in the liver of rats. Continuous injection of TAA solution resulted in increasing liver iron deposition over time. The intensity of iron deposition in liver tissue was also significantly reduced after bone mesenchymal stem cells (BMSCs) were injected. These findings indicated that confocal µ-XRF can be used as a nondestructive and quantitative method of evaluating hepatic iron deposition in hepatic fibrosis, and iron deposition may play an important role in the progression of hepatic fibrosis induced by TAA.

Efficacy and safety of stem cell therapy in cerebral palsy: A systematic review and meta-analysis.

Aim: Although the efficacy and safety of stem cell therapy for cerebral palsy has been demonstrated in previous studies, the number of studies is limited and the treatment protocols of these studies lack consistency. Therefore, we included all relevant studies to date to explore factors that might influence the effectiveness of treatment based on the determination of safety and efficacy. Methods: The data source includes PubMed/Medline, Web of Science, EMBASE, Cochrane Library, from inception to 2 January 2022. Literature was screened according to the PICOS principle, followed by literature quality evaluation to assess the risk of bias. Finally, the outcome indicators of each study were extracted for combined analysis. Results: 9 studies were included in the current analysis. The results of the pooled analysis showed that the improvements in both primary and secondary indicators except for Bayley Scales of Infant and Toddler Development were more skewed towards stem cell therapy than the control group. In the subgroup analysis, the results showed that stem cell therapy significantly increased Gross Motor Function Measure (GMFM) scores of 3, 6, and 12 months. Besides, improvements in GMFM scores were more skewed toward umbilical cord mesenchymal stem cells, low dose, and intrathecal injection. Importantly, there was no significant difference in the adverse events (RR = 1.13; 95% CI = [0.90, 1.42]) between the stem cell group and the control group. Conclusion: The results suggested that stem cell therapy for cerebral palsy was safe and effective. Although the subgroup analysis results presented guiding significance in the selection of clinical protocols for stem cell therapy, high-quality RCTs validations are still needed.

miR-666-3p Mediates the Protective Effects of Mesenchymal Stem Cell-derived Exosomes Against Oxygen-glucose Deprivation and Reoxygenation- induced Cell Injury in Brain Microvascular Endothelial Cells via Mitogen-activated Protein Kinase Pathway.

BACKGROUND: Previous studies have reported that mesenchymal stem cell (MSC)- derived exosomes can protect primary rat brain microvascular endothelial cells (BMECs) against oxygen-glucose deprivation and reoxygenation (OGD/R)-induced injury. OBJECTIVE: The aim was to identify the key factors mediating the protective effects of MSC-derived exosomes. METHODS: Primary rat BMECs were either pretreated or not pretreated with MSC-derived exosomes before exposure to OGD/R. Naïve cells were used as a control. After performing small RNA deep sequencing, quantitative reverse transcription polymerase chain reaction was performed to validate microRNA (miRNA) expression. The effects of rno-miR-666-3p on cell viability, apoptosis, and inflammation in OGD/R-exposed cells were assessed by performing the Cell Counting Kit 8 assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Moreover, the role of rno-miR-666-3p in regulating gene expression in OGD/R-exposed cells was studied using mRNA deep sequencing. Lastly, to evaluate whether mitogen-activated protein kinase 1 (MAPK1) was the target of rno-miR-666-3p, western blotting and the dual-luciferase assay were performed. RESULTS: MSC-derived exosomes altered the miRNA expression patterns in OGD/R-exposed BMECs. In particular, the expression levels of rno-miR-666-3p, rno-miR-92a-2-5p, and rnomiR- 219a-2-3p decreased in OGD/R-exposed cells compared with those in the control; however, MSC-derived exosomes restored the expression levels of these miRNAs under OGD/R conditions. rno-miR-666-3p overexpression enhanced cell viability and alleviated the apoptosis of OGD/R-exposed cells. Moreover, rno-miR-666-3p suppressed OGD/R-induced inflammation. mRNA deep sequencing revealed that rno-miR-666-3p is closely associated with the MAPK signaling pathway. Western blotting and the dual-luciferase assay confirmed that MAPK1 is the target of rnomiR- 666-3p. CONCLUSION: MSC-derived exosomes restore rno-miR-666-3p expression in OGD/R-exposed BMECs. Moreover, this specific miRNA exerts protective effects against OGD/R by suppressing the MAPK signaling pathway.

Mesenchymal Stem Cell-derived Exosomes Rescue Oxygen-Glucose Deprivation-induced Injury in Endothelial Cells.

OBJECTIVE: The effects of mesenchymal stem cell (MSC)-derived exosomes on brain microvascular endothelial cells under oxygen-glucose deprivation (OGD), which mimic cells in deep hypothermic circulatory arrest (DHCA) in vitro, are yet to be studied. METHODS: MSCs were co-cultured with primary rat brain endothelial cells, which were then exposed to OGD. Cell viability, apoptosis, the inflammatory factors (IL-1ß, IL-6, and TNF-α), and the activation of inflammation-associated TLR4-mediated pyroptosis and the NF-κB signaling pathway were determined. Furthermore, exosomes derived from MSCs were isolated and incubated with endothelial cells to investigate whether the effect of MSCs is associated with MSCderived exosomes. Apoptosis, cell viability, and the inflammatory response were also analyzed in OGD-induced endothelial cells incubated with MSC-derived exosomes. RESULTS: OGD treatment promoted endothelial cell apoptosis, induced the release of inflammatory factors IL-1ß, IL-6, and TNF-α, and inhibited cell viability. Western blot analysis showed that OGD treatment-induced TLR4, and NF-κB p65 subunit phosphorylation and caspase-1 upregulation, while co-culture with MSCs could reduce the effect of OGD treatment on endothelial cells. As expected, the effect of MSC-derived exosomes on OGD-treated endothelial cells was similar to that of MSCs. MSC-derived exosomes alleviated the OGD-induced decrease in the viability of endothelial cells, and increased levels of apoptosis, inflammatory factors, and the activation of inflammatory and inflammatory focal pathways. CONCLUSION: Both MSCs and MSC-derived exosomes attenuated OGD-induced rat primary brain endothelial cell injury. These findings suggest that MSC-derived exosomes mediate at least some of the protective effects of MSCs on endothelial cells.

Research progress in liver tissue engineering.

Liver transplantation is the definitive treatment for patients with end-stage liver diseases (ESLD). However, it is hampered by shortage of liver donor. Liver tissue engineering, aiming at fabricating new livers in vitro, provides a potential resolution for donor shortage. Three elements need to be considered in liver tissue engineering: seeding cell resources, scaffolds and bioreactors. Studies have shown potential cell sources as hepatocytes, hepatic cell line, mesenchymal stem cells and others. They need scaffolds with perfect biocompatiblity, suitable micro-structure and appropriate degradation rate, which are essential charateristics for cell attachment, proliferation and secretion in forming extracellular matrix. The most promising scaffolds in research include decellularized whole liver, collagens and biocompatible plastic. The development and function of cells in scaffold need a microenvironment which can provide them with oxygen, nutrition, growth factors, et al. Bioreactor is expected to fulfill these requirements by mimicking the living condition in vivo. Although there is great progress in these three domains, a large gap stays still between their researches and applications. Herein, we summarized the recent development in these three major fields which are indispensable in liver tissue engineering.