Search

Background. Intestinal fibrosis, one of the complications of inflammatory bowel disease (IBD), is associated with fistula and intestinal stricture formation. There are currently no treatments for fibrosis. Mesenchymal stem cell-derived exosomes have been proven to exert inhibitory and reversal effects in IBD and other organ fibrosis. In this study, we explored the role of human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Ex) in IBD-related fibrosis and its associated mechanism to provide new ideas for the prevention and treatment of IBD-related intestinal fibrosis. Methods. We established a DSS-induced mouse IBD-related intestinal fibrosis model and observed the effect of hucMSC-Ex on the mouse model. We also used the TGF-induced human intestinal fibroblast CCD-18Co to observe the role of hucMSC-Ex in the proliferation, migration, and activation of intestinal fibroblasts. Having observed that the extracellular-signal-regulated kinase (ERK) pathway in intestinal fibrosis can be inhibited by hucMSC-Ex, we treated intestinal fibroblasts with an ERK inhibitor to emphasize the potential target of ERK phosphorylation in the treatment of IBD-associated intestinal fibrosis. Results. In the animal model of IBD-related fibrosis, hucMSC-Ex alleviated inflammation-related fibrosis as evident in the thinning of the mice’s intestinal wall and decreased expression of related molecules. Moreover, hucMSC-Ex inhibited TGF-β-induced proliferation, migration, and activation of human intestinal fibroblasts, and ERK phosphorylation played a key role in IBD-associated fibrosis. The inhibition of ERK decreased the expression of fibrosis-related indicators such as α-SMA, fibronectin, and collagen I. Conclusion. hucMSC-Ex alleviates DSS-induced IBD-related intestinal fibrosis by inhibiting profibrotic molecules and intestinal fibroblast proliferation and migration by decreasing ERK phosphorylation.

Intestinal parasite infection (IPI) is still a very important public health issue. The severity of the parasitic disease has been reported as a high infection in immunocompromised patients and children. Hence, this study aimed to investigate the prevalence of intestinal parasites among immunocompromised patients and children with various gastrointestinal system complications in Sana’a city, Yemen, with different variables, including genus and age, and explore the risk factors associated with parasitic intestinal infections. The study socioeconomic data and certain behavioral and environmental risk factors and stool samples were collected from immunocompromised adult and children’s patients, including children (one to eight years old), pregnant women, diabetes mellitus patients, cancer patients, HIV patients, and older adults. Out of 436 fecal samples, the overall prevalence rate of IPIs among immunocompromised patients and children in Sana’a was 51.8%. In contrast, the rate of infection in children (26.1%) was higher than that in old patients (25.7%) and in females (38.5%) and higher than that in males (13.3%). The protozoa (44.5%) have been shown more than intestinal helminths (7.3%) in samples, and the most common intestinal protozoan was Giardia lamblia and Entamoeba histolytica (13.8% and 12.8%), respectively. The most common intestinal helminthiasis was Hymenolepis nana with 1.8%. Concluding that the rate of infection was high for several reasons, including lack of commitment to hygiene as not handwashing after using the toilet (88.9%), eating uncovered food (56.3%), poor sanitation as lack of water sources (59.5%), reduced health education, and presence of other family members infected by parasites (61.3%). Interventions are required to reduce intestinal parasites, including health education on personal hygiene for patients, increasing awareness, and improving the environment and healthcare system.

One file in MS word format contains the following information on methods: 1. Flow Cytometric Cell Sorting Analysis; 2. Reverse Transcription and Quantitative Real-Time PCR; 3. Western Blot Analysis; 4. ChIP Assay; 5. Immunocytochemistry; 6. Promoter Activity Analysis; 7. Transient transfection of Plasmids and siRNAs; 8. Cell Scratch-Wound Healing Assay; 9. Cell Invasion Assay; 10. Immunohistochemistry Analysis; 11. Animal Models of Tumorigenesis and Metastasis; 12. SUPPLEMENTAL REFERENCES

KLF4 and CD44 regulate cancer cell stemness, but their precise functions and roles in metastatic progression are not well understood. In this study, we used both inducible and genetic engineering approaches to assess whether the activities of these two factors intersect in pancreatic cancer. We found that genetic ablation of Klf4 in pancreatic cancer cells isolated from Klf4flox/flox mice drastically increased CD44 expression and promoted the acquisition of stem-like properties, whereas tetracycline-inducible expression of KLF4 suppressed these properties in vitro and in vivo. Further mechanistic investigation revealed that KLF4 bound to the CD44 promoter to negatively regulate transcription and also the expression of the CD44 variant. Moreover, in human pancreatic ductal adenocarcinoma (PDAC) tissues, the expression patterns of KLF4 and CD44 were mutually exclusive, and this inverse relationship was particularly striking in human metastatic pancreatic tumors and in autochthonous mouse models of PDAC. Taken together, our findings demonstrate that KLF4 acts as a tumor suppressor in PDAC cells that restricts metastatic behaviors through direct negative regulation of CD44, providing support for the clinical investigation of therapeutic approaches focusing on targeted KLF4 activation in advanced tumors. Cancer Res; 76(8); 2419–31. ©2016 AACR.

Purpose: The dismal prognosis of pancreatic cancer has been linked to poor tumor differentiation. However, molecular basis of pancreatic cancer differentiation and potential therapeutic value of the underlying molecules remain unknown. We investigated the mechanistic underexpression of Krüppel-like factor 4 (KLF4) in pancreatic cancer and defined a novel epigenetic pathway of its activation for pancreatic cancer differentiation and treatment.Experimental Design: Expressions of KLF4 and DNMT1 in pancreatic cancer tissues were determined by IHC and the genetic and epigenetic alterations of KLF4 in and KLF4′s impact on differentiation of pancreatic cancer were examined using molecular biology techniques. The function of dietary 3,3′-diindolylmethane (DIM) on miR-152/DNMT1/KLF4 signaling in pancreatic cancer was evaluated using both cell culture and animal models.Results: Overexpression of DNMT1 and promoter hypermethylation contributed to decreased KLF4 expression in and associated with poor differentiation of pancreatic cancer. Manipulation of KLF4 expression significantly affected differentiation marker expressions in pancreatic cancer cells. DIM treatment significantly induced miR-152 expression, which blocked DNMT1 protein expression and its binding to KLF4 promoter region, and consequently reduced promoter DNA methylation and activated KLF4 expression in pancreatic cancer cells. In addition, DIM treatment caused significant inhibition of cell growth in vitro and tumorigenesis in animal models of pancreatic cancer.Conclusions: This is the first demonstration that dysregulated KLF4 expression associates with poor differentiation of pancreatic cancer. Epigenetic activation of miR-152/DNMT1/KLF4 signaling pathway by dietary DIM causes differentiation and significant growth inhibition of pancreatic cancer cells, highlighting its translational implications for pancreatic and other cancers. Clin Cancer Res; 23(18); 5585–97. ©2017 AACR.

Supplementary Figure 1. Genetic and epigenetical alterations of KLF4 in pancreatic cancer; Supplementary Figure 2. A demonstration of LCM/ DNA methylation specific PCR analysis of KLF4 promoter methylation; Supplementary Figure 3. Comparison of DNMT1 and KLF4 expressions in pancreatic tissues determined by IHC analysis; Supplementary Figure 4. The effect of DIM treatment on cell cycle progression; Supplementary Figure 5. Spheroid colony formation and tumorigenesis; Supplementary Figure 6. Tumorigenesis assay using orthotopic pancreatic cancer mouse model; Supplementary Figure 7. The effect of DIM treatment on gene expression in pancreatic cancer cells; Supplementary Figure 8. The effects of DIM and miR-152 on gene expression.

Supplementary Methods

Supplementary Table 1. Patients' Characteristics and KLF4 Expression; Supplementary Table 2. Patients' Characteristics and DNMT1 Expression; Table 3. Upregulated microRNAs after DIM Treatment; Table 4. Down-regulated microRNAs after DIM Treatment.

Supplementary Figure 1-7 Figure S1. Effects of KLF4 overexpression on tumorsphere formation and liver metastasis of cancer stem-like cells; Figure S2. Effect of Klf4 gene disruption on cell morphology of mouse pancreatic cancer cells; Figure S3. IHC staining of Klf4 and CD44 expressions in intestinal tissues Figure S4. KLF4 and CD44 expressions in PANC-1 cells; Figure S5. KLF4 inhibits CD44v and ESRP-1 expressions in pancreatic and colon cancer cells; Figure S6. KLF4 expression correlates with metastatic potential in human cancer cells; Figure S7. KLF4/CD44 expressions in primary and metastatic tumor tissues

Supplemental Figure Legends Figure S1. Effects of KLF4 overexpression on tumorsphere formation and liver metastasis of cancer stem-like cells; Figure S2. Effect of Klf4 gene disruption on cell morphology of mouse pancreatic cancer cells; Figure S3. IHC staining of Klf4 and CD44 expressions in intestinal tissues; Figure S4. KLF4 and CD44 expressions in PANC-1 cells; Figure S5. KLF4 inhibits CD44v and ESRP-1 expressions in pancreatic and colon cancer cells; Figure S6. KLF4 expression correlates with metastatic potential in human cancer cells; Figure S7. KLF4/CD44 expressions in primary and metastatic tumor tissues

Supplementary Tables Table S1. CD44 expression and clinicopathologic characteristics; Table S2. KLF4 expression and clinicopathologic characteristics; Table S3. Specific primers for target and control genes; Table S4. Antibodies for target and control protein expression in Western blot analyses

Extracellular vesicles (EVs) are vesicular bodies (40-1000 nm) with double-layer membrane structures released by different cell types into extracellular environments, including apoptosis bodies, microvesicles, and exosomes. Exosomes (30-100 nm) are vesicles enclosed by extracellular membrane and contain effective molecules of secretory cells. They are derived from intracellular multivesicular bodies (MVBs) that fuse with the plasma membrane and release their intracellular vesicles by exocytosis. Research has shown that almost all human cells could secrete exosomes, which have a certain relationship with corresponding diseases. In chronic liver diseases, exosomes release a variety of bioactive components into extracellular spaces, mediating intercellular signal transduction and materials transport. Moreover, exosomes play a role in the diagnosis, treatment, and prognosis of various chronic liver diseases as potential biomarkers and therapeutic targets. Previous studies have found that mesenchymal stem cell-derived exosomes (MSC-ex) could alleviate acute and chronic liver injury and have the advantages of high biocompatibility and low immunogenicity. In this paper, we briefly summarize the role of exosomes in the pathogenesis of different chronic liver diseases and the latest research progresses of MSC-ex as the clinical therapeutic targets.

The ability of extracellular vesicles (EVs) to regulate a broad range of cellular processes has recently been used to treat diseases. Growing evidence indicates that EVs play a cardioprotective role in heart disease by activating beneficial signaling pathways. Multiple functional components of EVs and intracellular molecular mechanisms are involved in the process. To overcome the shortcomings of native EVs such as their heterogeneity and limited tropism, a series of engineering approaches has been developed to improve the therapeutic efficiency of EVs. In this review, we present an overview of the research and future directions for EVs-based cardiac therapies with an emphasis on EVs-mediated delivery of therapeutic agents. The advantages and limitations of various modification strategies are discussed, and possible opportunities for improvement are proposed. An in-depth understanding of the endogenous properties of EVs and EVs engineering strategies could lead to a promising cell-free therapy for cardiac repair.

Metabolic diseases, including obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD), are rising in both incidence and prevalence and remain a major global health and socioeconomic burden in the twenty-first century. Despite an increasing understanding of these diseases, the lack of effective treatments remains an ongoing challenge. Mitochondria are key players in intracellular energy production, calcium homeostasis, signaling, and apoptosis. Emerging evidence shows that mitochondrial dysfunction participates in the pathogeneses of metabolic diseases. Exogenous supplementation with healthy mitochondria is emerging as a promising therapeutic approach to treating these diseases. This article reviews recent advances in the use of mitochondrial transplantation therapy (MRT) in such treatment.

As a group of nonspecific inflammatory diseases affecting the intestine, inflammatory bowel disease (IBD) exhibits the characteristics of chronic recurring inflammation, and was proven to be increasing in incidence (Kaplan, 2015). IBD induced by genetic background, environmental changes, immune functions, microbial composition, and toxin exposures (Sasson et al., 2021) primarily includes ulcerative colitis (UC) and Crohn's disease (CD) with complicated clinical symptoms featured by abdominal pain, diarrhea, and even blood in stools (Fan et al., 2021; Huang et al., 2021). UC is mainly limited to the rectum and the colon, while CD usually impacts the terminal ileum and colon in a discontinuous manner (Ordás et al., 2012; Panés and Rimola, 2017). In recent years, many studies have suggested the lack of effective measures in the diagnosis and treatment of IBD, prompting an urgent need for new strategies to understand the mechanisms of and offer promising therapies for IBD.

Activated hepatic stellate cells (HSCs) are significant in liver fibrosis. Our past investigations have shown that human umbilical cord mesenchymal stem cells (hucMSCs) and their secreted exosomes (MSC-ex) could alleviate liver fibrosis via restraining HSCs activation. However, the mechanisms underlying the efficacy were not clear. Ferroptosis is a regulatory cell death caused by excessive lipid peroxidation, and it plays a vital role in the occurrence and development of liver fibrosis. In the present study, we aimed to study the proferroptosis effect and mechanism of MSC-ex in HSCs. MSC-ex were collected and purified from human umbilical cord MSCs. Proferroptosis effect of MSC-ex was examined in HSCs line LX-2 and CCl4 induced liver fibrosis in mice. Gene knockdown or overexpression approaches were used to investigate the biofactors in MSC-ex-mediated ferroptosis regulation. Results: MSC-ex could trigger HSCs ferroptosis by promoting ferroptosis-like cell death, ROS formation, mitochondrial dysfunction, Fe2+ release, and lipid peroxidation in human HSCs line LX-2. Glutathione peroxidase 4 (GPX4) is a crucial regulator of ferroptosis. We found that intravenous injection of MSC-ex significantly decreased glutathione peroxidase 4 (GPX4) expression in activated HSCs and collagen deposition in experimental mouse fibrotic livers. Mechanistically, MSC-ex derived BECN1 promoted HSCs ferroptosis by suppressing xCT-driven GPX4 expression. In addition, ferritinophagy and necroptosis might also play a role in MSC-ex-promoted LX-2 cell death. Knockdown of BECN1 in MSC diminished proferroptosis and anti-fibrosis effects of MSC-ex in LX-2 and fibrotic livers. MSC-ex may promote xCT/GPX4 mediated HSCs ferroptosis through the delivery of BECN1 and highlights BECN1 as a potential biofactor for alleviating liver fibrosis.

Inflammatory bowel disease (IBD) can be caused by a variety of factors, including hereditary and environmental influences, that lead to dysfunction of the intestinal immune system. Mesenchymal stem cells (MSCs) exhibit important regulatory roles in relieving inflammation and repairing damaged tissues. Although neutrophils are important participants in the development of inflammatory reactions, they are also essential for maintaining intestinal balance during the process of mitigation of IBD by MSCs. Here, we constructed a dextran sulfate sodium (DSS)-induced mouse IBD model and evaluated the effects of treatment with human umbilical cord MSCs. Mouse body weight, faecal traits, colon/spleen gross morphology, tissue histology and immunohistochemical staining, and inflammatory factors were analysed. Magnetic beads were used to sort infiltrating neutrophils from intestinal tissues, and their phenotypes were identified. The neutrophil inflammatory environment was also simulated in vitro, and signalling pathways involved in MSC regulation of neutrophil phenotype were analysed. Human umbilical cord MSCs effectively alleviated DSS-induced weight loss, colon shortening, and intestinal mucosal injury, and reduced clinical disease activity index. The number of neutrophils that infiltrated the intestines of mice treated with human umbilical cord MSCs were decreased and polarised toward the N2 phenotype; at the same time, ERK phosphorylation was inhibited. In vitro experiments showed that addition of the ERK phosphorylation inhibitor, PD98059, down-regulated the expression of N1 neutrophils, while up-regulating that of N2 neutrophils. The colon tissues from patients with IBD were infiltrated with neutrophils. Further, relative to healthy controls, the markers of N1 neutrophils (ICAM-1, FAS, and CCL3) were highly expressed in colon tissues from patients with IBD, whereas the markers of N2 neutrophils (VEGF, CCL2, and CXCR4) were almost undetectable. In conclusion, during alleviation of IBD, human umbilical cord MSCs polarise neutrophils toward the "N2" phenotype by inhibiting activation of ERK signalling.

Background:Recent studies have shown the great value of cell therapy over the past few decades. Mesenchymal stem cells (MSCs) have been reported to treat various degenerative diseases not through their differentiation potential but through their paracrine factors of the extracellular vesicle (EV) including exosomes. Exosomes are nanosized (70~150 nm) membrane-bound extracellular vesicles, not only involved in cell-to-cell communication but also in the development of tissue injury repair.Objective:As more researchers proved the enormous potential of exosomes in the field of repairing damaged tissue currently, it is urgent to explore the concrete mechanism and make exosomes to be a practical treatment tool in clinical medicine. In our study, we analyzed and summarized the work on tissue repair via exosomes in order to give some suggestions about the application of exosomes in clinical reality in the future.Results:MSC-derived exosomes (MSC-Ex) contain a wide variety of functional proteins, mRNAs, miRNAs and signaling lipids. Compared with their parent cells, MSC-Ex are more stable and can reduce the inherent safety risks in administering viable cells such as the risk of occlusion in microvasculature. MSC-Ex can be used to develop a cell-free exosome-based therapy for regenerative medicine, and may provide an alternative to MSC-based therapy.Conclusion:This review summarizes the most recent knowledge of therapeutic potential of MSC-Ex in the liver, heart, kidney, bone, brain diseases and cancer, as well as their associated challenges and opportunities.

Mesenchymal stem cells (MSCs) exert powerful immunosuppression in inflammatory bowel disease (IBD). Macrophages are the dominant inflammatory cells in enteritis regulated via MSCs. However, the roles of macrophages in the process of MSCs attenuating IBD and the mechanisms of MSCs regulating macrophages are largely unknown. In this study, DSS- (dextran sulfate sodium salt-) induced IBD in macrophage-depleted models of CD11b-DTR mice was used to study the relationship between hucMSCs (human umbilical cord mesenchymal stromal cells) and macrophage. Body weights, disease activities, and pathological changes were documented to assess the therapeutic effects of hucMSCs. Furthermore, hucMSCs transfected with miR148b-5p mimics and miR148b-5p inhibitors were cocultured with LPS-induced RAW264.7 cells to investigate the role of miR148b-5p in hucMSC-regulated colitis. The outcome indicated that hucMSCs attenuated the IBD by downregulating 15-lox-1 expression in macrophages. Further findings pointed out that hucMSCs transfected with miR148b-5p mimics could be elevated to promote the tissue repair and inhibit the expression of 15-lox-1 but failed to perform the function of easing enteritis when treated with miR148b-5p inhibitors. In conclusions, we propose that hucMSCs attenuate IBD by releasing miR148b-5p to inhibit the expression of 15-lox-1 in macrophages.

Mesenchymal stem cells (MSCs) therapy has been applied to a wide range of diseases with excessive immune response, including inflammatory bowel disease (IBD), owing to its powerful immunosuppression and its ability to repair tissue lesions. Different sources of MSCs show different therapeutic properties. Engineering managements are able to enhance the immunomodulation function and the survival of MSCs involved in IBD. The therapeutic mechanism of MSCs in IBD mainly focuses on cell-to-cell contact and paracrine actions. One of the promising therapeutic options for IBD can focus on exosomes of MSCs. MSCs hold promise for the treatment of IBD-associated colorectal cancer because of their tumor-homing function and chronic inflammation inhibition. Encouraging results have been obtained from clinical trials in IBD and potential challenges caused by MSCs therapy are getting solved. This review can assist investigators better to understand the research progress for enhancing the efficacy of MSCs therapy involved in IBD and CAC.

The underlying mechanisms of human umbilical cord mesenchymal stem cells (hucMSCs) and their exosomes (hucMSC-Exs), which play significant roles in skin wound healing, remain poorly understood. By using a rat model of deep second-degree burn injury, the roles of hucMSC-Exs in angiogenesis and cutaneous wound healing in vivo were investigated. We found that hucMSC-Exs accelerated skin wound healing and angiogenesis, inducing a higher wound-closure rate and increased expression of CD31 in vivo. We also discovered that hucMSC-Exs contained angiopoietin-2 (Ang-2), and treatment with hucMSC-Exs enhanced the expression of the Ang-2 protein in the wound area and human umbilical vein endothelial cells (HUVECs) through exosomal-mediated Ang-2 transfer. Moreover, hucMSC-Exs promoted the proliferative, migratory, and tube-forming ability of HUVECs. Furthermore, overexpression of Ang-2 in hucMSC-Exs further enhanced HUVEC migration and tube formation and exerted therapeutic and proangiogenic effects in cutaneous wounds in rats, whereas knockdown of Ang-2 in hucMSC-Exs abrogated these therapeutic and proangiogenic effects. Taken together, our results indicated that hucMSC-Ex-derived Ang-2 plays a significant role in tube formation of HUVECs and promotion of angiogenesis, and further suggested that hucMSC-Ex-based therapy may serve as a promising therapeutic approach for promoting cutaneous wound healing.

Exosomes from human umbilical cord mesenchymal stem cells (hucMSC-Ex) have been suggested as novel nanomaterials for regenerative medicine. Here we explored the roles of hucMSC-Ex through regulating Yes-associated protein (YAP) in renal injury repair by using rat unilateral ureteral obstruction (UUO) models. Our study identified mechanical stress induced YAP nucleus expression and stimulated collagen deposition and interstitial fibrosis in the kidney. Then, infusion with hucMSC-Ex promoted YAP nuclear cytoplasmic shuttling and ameliorated renal fibrosis in UUO model. Interestingly, hucMSC-Ex delivered casein kinase 1δ (CK1δ) and E3 ubiquitin ligase β-TRCP to boost YAP ubiquitination and degradation. Knockdown of CK1δ and β-TRCP in hucMSC decreased the repairing effects of hucMSC-Ex on renal fibrosis. Our results suggest that hucMSC-Ex attenuates renal fibrosis through CK1δ/β-TRCP inhibited YAP activity, unveiling a new mechanism for the therapeutic effects of hucMSC-Ex on tissue injury and offering a potential approach for renal fibrosis treatment.

Pancreatic cancer is one of the most lethal diseases around the world, for hardly detection and poor prognosis. Recent years, functions of the tumor microenvironment and immune cells attract people’s view and there is emerging evidence implicating some immune cells hold the key points in the metabolism, invasion, and metastasis in pancreatic cancer. In this review, we highlight some main immune cells, such as Tumor-associated neutrophils (TANs) and macrophages (TAMs), Pancreatic stellate cells (PSCs), Myeloid-derived suppressor cells (MDSCs), and Regulatory T cells (Tregs). Furthermore, we review current clinical applications and discuss potential values in future.

The deficiency or mutation of p53 has been linked to several types of cancers. The mesenchymal stem cell (MSC) is an important component in the tumor microenvironment, and exosomes secreted by MSCs can transfer bioactive molecules, including proteins and nucleic acid, to other cells in the tumor microenvironment to influence the progress of a tumor. However, whether the state of p53 in MSCs can impact the bioactive molecule secretion of exosomes to promote cancer progression and the regulatory mechanism remains elusive. Our study aimed to investigate the regulation of ubiquitin protein ligase E3 component n-recognin 2 (UBR2) enriched in exosomes secreted by p53 deficient mouse bone marrow MSC (p53–/–mBMMSC) in gastric cancer progression in vivo and in vitro. We found that the concentration of exosome was significantly higher in p53–/–mBMMSC than that in p53 wild-type mBMMSC (p53+/+mBMMSC). In particular, UBR2 was highly expressed in p53–/–mBMMSC cells and exosomes. P53–/–mBMMSC exosomes enriched UBR2 could be internalized into p53+/+mBMMSC and murine foregastric carcinoma (MFC) cells and induce the overexpression of UBR2 in these cells which elevated cell proliferation, migration, and the expression of stemness-related genes. Mechanistically, the downregulation of UBR2 in p53–/–mBMMSC exosomes could reverse these actions. Moreover, a majority of Wnt family members, β-catenin, and its downstream genes (CD44, CyclinD1, CyclinD3, and C-myc) were significantly decreased in MFC knockdown UBR2 and β-catenin depletion, an additional depletion of UBR2 had no significant difference in the expression of Nanog, OCT4, Vimentin, and E-cadherin. Taken together, our findings indicated that p53–/–mBMMSC exosomes could deliver UBR2 to target cells and promote gastric cancer growth and metastasis by regulating Wnt/β-catenin pathway.

Mesenchymal stem cells (MSCs) are a critical component of the tumor microenvironment. Upon distinct pathological stimulus, MSCs show phenotypic and functional changes. Gastric cancer is one of the leading causes of cancer-related deaths worldwide. The roles and mechanisms of MSCs in gastric cancer have not been well characterized. In the present study, we investigated the roles of MSCs in the malignant transformation from gastritis to gastric cancer using an N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric cancer model. We isolated MSCs from the gastric tissues of normal (RGN-MSCs) and MNNG-exposed rats (RGI-MSCs), and compared the biological properties of RGI-MSCs with RGN-MSCs. We found that RGI-MSCs had increased proliferative and migratory capabilities than these capacities noted in the RGN-MSCs. In addition, RGI-MSCs produced higher levels of IL-6, CXCL10 and MCP-1 than RGN-MSCs. Moreover, RGI-MSCs promoted the migration of normal gastric mucosa epithelial cells by inducing epithelial-mesenchymal transition (EMT). The upregulation of miR-374 in RGI-MSCs was partially responsible for their increased proliferative and migratory capabilities. Collectively, our findings provide new evidence for the roles of MSCs in gastric carcinogenesis, suggesting that targeting gastric cancer-associated MSCs may represent a novel avenue for gastric cancer therapy.

Exosomes are small biological membrane vesicles secreted by various cells, including mesenchymal stem cells (MSCs). We previously reported that MSC-derived exosomes (MSC-Ex) can elicit hepatoprotective effects against toxicant-induced injury. However, the success of MSC-Ex-based therapy for treatment of liver diseases and the underlying mechanisms have not been well characterized. We used human umbilical cord MSC-derived exosome (hucMSC-Ex) administrated by tail vein or oral gavage at different doses and, in engrafted liver mouse models, noted antioxidant and anti-apoptotic effects and rescue from liver failure. A single systemic administration of hucMSC-Ex (16 mg/kg) effectively rescued the recipient mice from carbon tetrachloride (CCl4)-induced liver failure. Moreover, hucMSC-Ex-derived glutathione peroxidase1 (GPX1), which detoxifies CCl4 and H2O2, reduced oxidative stress and apoptosis. Knockdown of GPX1 in hucMSCs abrogated antioxidant and anti-apoptotic abilities of hucMSC-Ex and diminished the hepatoprotective effects of hucMSC-Ex in vitro and in vivo. Thus, hucMSC-Ex promote the recovery of hepatic oxidant injury through the delivery of GPX1.

Laboratory exercise is helpful for medical students to understand the basic principles of molecular biology and to learn about the practical applications of molecular biology. We have designed a lab course on molecular biology about the determination of single nucleotide polymorphism (SNP) in human REV3 gene, the product of which is a subunit of DNA polymerase ζ and SNPs in this gene are associated with altered susceptibility to cancer. This newly designed experiment is composed of three parts, including genomic DNA extraction, gene amplification by PCR, and genotyping by RFLP. By combining these activities, the students are not only able to learn a series of biotechniques in molecular biology, but also acquire the ability to link the learned knowledge with practical applications. This comprehensive experiment will help the medical students improve the conceptual understanding of SNP and the technical understanding of SNP detection. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):299-304, 2017.

Background: Phosphodiesterase 3A (PDE3A) and phosphodiesterase 3B (PDE3B) play a critical role in the regulation of intracellular level of adenosine 3´,5´-cyclic monophosphate (cyclic AMP, cAMP) and guanosine 3´,5´-cyclic monophosphate (cyclic GMP, cGMP). Subsequently PDE3 inhibitors have shown to relax vascular and inhibit platelet aggregation in cardiovascular disease. Objectives: In this study, our aim was to establish a method of expression for the recombinant human PDE3A and PDE3B proteins in insect cells using baculovirus expression system in order to investigate the activity of the expressed PDE3A and PDE3B proteins. Materials and Methods: The full length human PDE3A and PDE3B cDNA were cloned into recombinant baculovirus and transfected into the SF9 insect cells. Recombinant proteins were collected at 48 h, 60 h, 72 h, and 84 h post transfection. Transfection of recombinant baculovirus was verified by the morphological changes of the SF9 cells. Expression of human PDE3A and PDE3B was detected by using RT-PCR and western blot, respectively. The 125I RIA method was used to determine the level of adenosine 3´,5´-cyclic monophosphate cAMP and cGMP, correspondingly. The activity of the expressed PDE3A and PDE3B proteins were investigated by cAMP and cGMP dsgradation with or without addition of milrinone, a potent and selective PDE inhibitor. Results: Recombinant human PDE3A and PDE3B proteins were stably expressed in SF9 cells and could be detected by distinct morphological changes in the SF9 cells, RT-PCR, and western blot at 48 h post-transfection. The molecular weights of the recombinant PDE3A and PDE3B molecular weights proteins were about 120 KDa and 135 KDa, respectively. Results of 125I RIA assay showed that the levels of cAMP and cGMP were significantly decreased after incubation with the expressed PDE3A and PDE3B proteins. Furthermore, degradation of cAMP and cGMP through the activity of PDE3A and PDE3B was suppressed following to the addition of milrinone. Conclusions: Recombinant human PDE3A and PDE3B could be expressed in SF9 cells using baculovirus expression system, and thus provides the basic material for studying human PDE3A and PDE3B activity.

Approximately 18.1×106 new cases of cancer were recorded globally in 2018, out of which 9.6 million died. It is known that people who have Inflammatory Bowel Disease (IBD) turn to be prone to increased risks of developing colorectal cancer (CRC), which has global incident and mortality rates of 10.2% and 9.2%, respectively. Over the years, conventional treatments of IBD and its associated CRC have been noted to provide scarce desired results and often with severe complications. The introduction of biological agents as a better therapeutic approach has witnessed a great deal of success in both experimental and clinical models. With regard to mesenchymal stem cell (MSC) therapy, the ability of these cells to actively proliferate, undergo plastic differentiation, trigger strong immune regulation, exhibit low immunogenicity, and express abundant trophic factors has ensured their success in regenerative medicine and immune intervention therapies. Notwithstanding, MSC-based therapy is still confronted with some challenges including the likelihood of promoting tumor growth and metastasis, and possible overestimated therapeutic potentials. We review the success story of MSC-based therapy in IBD and its associated CRC as documented in experimental models and clinical trials, examining some of the challenges encountered and possible ways forward to producing an optimum MSC therapeutic imparts.

Background Mesenchymal stromal cells (MSCs) have attracted intense interest due to their powerful intrinsic properties of self-regeneration, immunomodulation and multi-potency, as well as being readily available and easy to isolate and culture. Notwithstanding, MSC based therapy suffers reduced efficacy due to several challenges which include unfavorable microenvironmental factors in vitro and in vivo. Body In the quest to circumvent these challenges, several modification techniques have been applied to the naïve MSC to improve its inherent therapeutic properties. These modification approaches can be broadly divided into two groups to include genetic modification and preconditioning modification (using drugs, growth factors and other molecules). This field has witnessed great progress and continues to gather interest and novelty. We review these innovative approaches in not only maintaining, but also enhancing the inherent biological activities and therapeutics of MSCs with respect to migration, homing to target site, adhesion, survival and reduced premature senescence. We discuss the application of the improved modified MSC in some selected human diseases. Possible ways of yet better enhancing the therapeutic outcome and overcoming challenges of MSC modification in the future are also elaborated. Conclusion The importance of prosurvival and promigratory abilities of MSCs in their therapeutic applications can never be overemphasized. These abilities are maintained and even further enhanced via MSC modifications against the inhospitable microenvironment during culture and transplantation. This is a turning point in MSC-based therapy with promising preclinical studies and higher future prospect.

Background: Tumor-associated macrophages (TAMs) and microvessel density (MVD) play an essential role for tumor progression in prostate cancer (PCa). In this study, we evaluated the association between TAMs, the infiltration with tumor angiogenesis and the response to androgen deprivation therapies (ADTs) in PCa to evaluate TAM infiltration as a predictive factor for PCa survival. Materials and methods: Fifty-four specimens were collected and stained with CD 68 antibody to investigated TAM infiltration in tumor. Von Willebrand factor was stained to evaluate MVD around the cancer foci. We assessed the association between patient's age, preoperative serum prostate-specific antigen, pathologic Gleason sum (GS), TAM infiltration, MVD, and the response to ADT for 5 years after PCa diagnosis. Results: The median TAM was observed in 28 (6-76)/high power field (x400). Increasing TAM correlated with increasing tumor angiogenesis (P < 0.001, r = 0.61), and the response to ADT was significantly better in patients with fewer TAMs (28) (P = 0.003). TAM infiltration was significantly higher in those with higher serum prostate-specific antigen, higher GS, and metastasis. Multivariate analysis showed that GS, ADT type, and MVD number were significant prognostic factors for response to ADT in PCa (P < 0.0001). An increased infiltration of TAM [hazards ratio (HR) = 4.47; 95% confidence interval (CI): 1.97–10.15], MVD (HR = 2.66; 95% CI: 1.27–5.61), metastatic status (HR = 2.29; 95% CI: 0.14-0.60), and prostate volume (HR = 2.19; 95% CI: 1.27–3.12) significantly correlated with shorter survival in PCa patients by univariate analysis (P < 0.05). Multivariate analyses revealed that TAM and metastatic status significantly correlated with poor overall survival. Conclusions: TAM infiltration is associated with response to ADT and increased tumor angiogenesis in PCa. GS, ADT type, and MVD in PCa specimens are useful predictive factors for poor response to ADT. Increasing TAM and positive metastatic status were prognostic factors for a poorer survival in PCa patients.

The role of mesenchymal stem cells (MSCs) in kidney injury repair has been studied widely. However, the underlying molecular mechanism remains unclear. We profiled the altered microRNAs in renal tissues from cisplatin-induced acute kidney injury (AKI) rats treated with or without rat bone marrow MSCs (rMSCs). We observed that microRNA-146b (miR-146b) expression was considerably upregulated in renal tissues from AKI rats compared with that in healthy rats, and the expression decreased following MSC treatment after cisplatin administration. At the early stage of AKI, serum miR-146b levels exhibited a rapid increase that was even faster than that of two conventional renal function indexes: serum creatinine and blood urea nitrogen levels. Furthermore, the serum miR-146b levels in AKI patients were higher than those in healthy people. In vitro exposure to cisplatin also increased miR-146b expression in renal tubular epithelial cells (TECs). miR-146b knockdown protected renal TECs from cisplatin-induced apoptosis and promoted their proliferation. Moreover, ErbB4 was identified as a direct target of miR-146b, and miR-146b inhibition induced ErbB4 expression, resulting in enhanced proliferation of injured renal TECs. In addition, restoration by rMSCs could be controlled through ErbB4 downregulation. In conclusion, elevated miR-146b expression contributes to cisplatin-induced AKI, partly through ErbB4 downregulation. miR-146b might be an early biomarker for AKI, and miR-146b inhibition could be a novel strategy for AKI treatment. Significance The present study found that microRNA-146b (miR-146b) might be a novel biomarker for acute kidney injury and an indicator for its recovery after treatment with mesenchymal stem cells (MSCs). The results showed that in acute kidney injury induced by cisplatin, miR-146b in serum increased more quickly than did the usual indexes of kidney injury and decreased with restoration of MSCs. In addition, inhibition of miR-146b could ameliorate the apoptosis induced by cisplatin and potentially improve the proliferation by freeing ErbB4 and its downstream proteins.

Numerous studies showed that mesenchymal stem cells derived exosome (MSC-Ex) markedly enhanced tissue regeneration, however, the issue of whether MSC-Ex could control stem cells expansion after a regenerative response to prevent tissue from overcrowding and dysplasia remains to be established. Herein, we found that human umbilical cord MSC (hucMSC)-exosomal14-3-3ζ mediated the binding of YAP and p-LATS by forming a complex to promote the phosphorylation of YAP, which orchestrate exosomal Wnt4 signal in cutaneous regeneration. First, we assessed deep second-degree burn rats treated with hucMSC-Ex and discovered that hucMSC-Ex promoting self-regulation of Wnt/β-catenin signaling at the remodeling phase of cutaneous regeneration. HucMSC-Ex restricted excessive skin cell expansion and collagen deposition at 4 weeks. Under high cell density conditions, hucMSC-Ex inhibited Wnt/β-catenin signaling through induction of YAP phosphorylation. Second, hucMSC-Ex proteomic analysis revealed that 14-3-3 proteins could be transported by exosome. Using gain- and loss-of-function studies, our results showed that hucMSC-exosomal 14-3-3ζ controlled YAP activities and phosphorylation at Ser127 site, and were required for the binding of YAP and p-LATS. Further studies revealed that 14-3-3ζ recruited YAP and p-LATS to form a complex under high cells density status and 14-3-3ζ other than YAP or p-LATS was the key regulatory molecule of this complex. These findings collectively indicate that hucMSC-Ex functions not only as an “accelerator” of the Wnt/β-catenin signal to repair damaged skin tissue but also as a “brake” of the signal by modulating YAP to orchestrate controlled cutaneous regeneration.

Understanding the molecular mechanisms of tumor initiation has significant impact on early cancer detection and intervention. To define the role of KLF4 in pancreatic ductal adenocarcinoma (PDA) initiation, we used molecular biological analyses and mouse models of klf4 gain- and loss-of-function and mutant Kras. KLF4 is upregulated in and required for acinar-to-ductal metaplasia. Klf4 ablation drastically attenuates the formation of pancreatic intraepithelial neoplasia induced by mutant Kras(G12D), whereas upregulation of KLF4 does the opposite. Mutant KRAS and cellular injuries induce KLF4 expression, and ectopic expression of KLF4 in acinar cells reduces acinar lineage- and induces ductal lineage-related marker expression. These results demonstrate that KLF4 induces ductal identity in PanIN initiation and may be a potential target for prevention of PDA initiation.

Our and other groups have discovered that mesenchymal stem cells (MSCs) derived exosomes are a novel therapeutical modality for many diseases. In this study, we summarized a method to extract and purify hucMSCs-exosomes using ultrafiltration and gradient centrifugation in our laboratory and proved that hucMSCs-exosomes prepared according to our procedure were stable and bioactive. Results showed that exosomes derived from hucMSC were 40~100 nm and CD9 and CD81 positive. Functionally, hucMSCs-exosomes promoted cell proliferation and protected against oxidative stress-induced cell apoptosisin vitroby activation of ERK1/2 and p38. Interestingly, UV exposure abrogated the regulatory roles of exosomes under oxidative stress, indicating that hucMSCs-exosomes may regulate cell growth and apoptosis by exosomal shuttle of RNA. Furthermore, cytokine profile analysis revealed that hucMSCs-exosomes contained high dose of IL-6, IL-8, and other cytokines. The established method is practical and efficient, which provides a basis for further evaluating the potential of hucMSCs-exosomes as therapeutic agents.

Exosomes are nanosized extracellular vesicles (EVs) that show great promise in tissue regeneration and injury repair as mesenchymal stem cell (MSC). MSC has been shown to alleviate diabetes mellitus (DM) in both animal models and clinical trials. In this study, we aimed to investigate whether exosomes from human umbilical cord MSC (hucMSC-ex) have a therapeutic effect on type 2 DM (T2DM). We established a rat model of T2DM using a high-fat diet and streptozotocin (STZ). We found that the intravenous injection of hucMSC-ex reduced blood glucose levels as a main paracrine approach of MSC. HucMSC-ex partially reversed insulin resistance in T2DM indirectly to accelerate glucose metabolism. HucMSC-ex restored the phosphorylation (tyrosine site) of the insulin receptor substrate 1 and protein kinase B in T2DM, promoted expression and membrane translocation of glucose transporter 4 in muscle, and increased storage of glycogen in the liver to maintain glucose homeostasis. HucMSC-ex inhibited STZ-induced β-cell apoptosis to restore the insulin-secreting function of T2DM. Taken together, exosomes from hucMSC can alleviate T2DM by reversing peripheral insulin resistance and relieving β-cell destruction, providing an alternative approach for T2DM treatment.

Exosomes released from mesenchymal stem cells (MSCs) have an anti-inflammatory effect and can repair tissue injuries. Ubiquitination plays an important role in the regulation of various biological functions, including the regulation of inflammation. However, it remains unknown whether exosomes from human umbilical cord mesenchymal stem cells (hucMSC-ex) may cure the mice of DSS-induced inflammatory bowel disease (IBD) through the ubiquitin modification. In this study, we aimed to investigate the therapeutic effect and probe the mechanism relating to ubiquitination underlying the hucMSC-ex treatment in DSS-induced IBD of mice. HucMSC-ex significantly improved the symptoms of IBD in mice. In the IBD group, the gene expression levels of TNF-α, IL-1β, IL-6, NAe1, E2M and Uba3 dramatically increased while those of IL-10 and IP-10 decreased. The gene expression level in the group of hucMSC-ex treatment was adversed to that in the group of IBD. In the hucMSC-ex treated group, western blot results showed that the protein expressions of K48, K63 and FK2 have significantly decreased. Compared with that in the IBD mice, the mice treated by hucMSC-ex could recover the integrity of tissue structure. Our results indicated that exosomes from hucMSCs have profound effects on alleviating DSS-induced IBD and may exert their function by regulating the ubiquitin modification level.

MicroRNA-373 (miR-373) has been reported to be an oncogene in a number of solid human tumors. However, the role of miR‑373 in gastric cancer has not been completely elucidated and the mechanisms remain unclear. In the present study, we compared miR‑373 expression between clinical gastric cancer tissues and paired non‑tumorous tissues by reverse transcription‑quantitative polymerase chain reaction. The impact of miR‑373 on proliferation, migration and invasion in gastric cancer cells was additionally investigated. Hsa‑miR‑373 mimics were applied to mimic the function of endogenous miR‑373. A colony formation assay and flow cytometry were performed to analyze the proliferation of gastric cancer cells. Wound healing and Transwell invasion assays were employed to detect the migratory and invasive abilities of gastric cancer cells. Western blotting was used to test the expression of epithelial‑mesenchymal transition‑associated proteins. The results demonstrated that the level of miR‑373 in gastric cancer was upregulated compared with paired non‑tumorous tissues. It was confirmed that miR‑373 inhibited the migration and invasion of the gastric cancer cell lines SGC‑7901 and HGC‑27 by downregulating vimentin expression. The results of the present study demonstrated an oncogenic role of miR‑373 in the metastasis of human gastric cancer, and may provide a novel therapeutic strategy for gastric cancer.

The development of inflammation is mutually affected with damaged DNA and the abnormal expression of protein modification. Ubiquitination, a way of protein modification, plays a key role in regulating various biological functions including inflammation responses. The ubiquitin enzymes and deubiquitinating enzymes (DUBs) jointly control the ubiquitination. The fact that various ubiquitin linkage chains control the fate of the substrate suggests that the regulatory mechanisms of ubiquitin enzymes are central for ubiquitination. In inflammation diseases, the pro-inflammatory transcription factor NF-κB regulates transcription of pro-labour mediators in response to inflammatory stimuli and expression of numerous genes that control inflammation which is associated with ubiquitination. The ubiquitination regulates NF-κB signaling pathway with many receptor families, including NOD-like receptors (NLR), Toll-like receptors (TLR) and RIG-I-like receptors (RLR), mainly by K63-linked polyubiquitin chains. In this review, we highlight the study of ubiquitination in the inflammatory signaling pathway including NF-κB signaling regulated by ubiquitin enzymes and DUBs. Furthermore, it is emphasized that the interaction of ubiquitin-mediated inflammatory signaling system accurately regulates the inflammatory responses.

The reception and integration of the plethora of signals a cell receives from its microenvironment determines the cell's fate. CD44 functions as a receptor for hyaluronan and many other extracellular matrix components, as well as a cofactor for growth factors and cytokines, and thus, CD44 is a signaling platform that integrates cellular microenvironmental cues with growth factor and cytokine signals and transduces signals to membrane-associated cytoskeletal proteins or to the nucleus to regulate a variety of gene expression levels related to cell-matrix adhesion, cell migration, proliferation, differentiation, and survival. Accumulating evidence indicates that CD44, especially CD44v isoforms, are cancer stem cell (CSC) markers and critical players in regulating the properties of CSCs, including self-renewal, tumor initiation, metastasis, and chemoradioresistance. Furthermore, there is ample evidence that CD44, especially CD44v isoforms, are valuable prognostic markers in various types of tumors. Therefore, therapies that target CD44 may destroy the CSC population, and this holds great promise for the cure of life-threatening cancers. However, many challenges remain to determining how best to use CD44 as a biomarker and therapeutic target. Here we summarize the current findings concerning the critical role of CD44/CD44v in the regulation of cancer stemness and the research status of CD44/CD44v as biomarkers and therapeutic targets in cancer. We also discuss the current challenges and future directions that may lead to the best use of CD44/CD44v for clinical applications. Significance Mounting evidence indicates that cancer stem cells (CSCs) are mainly responsible for cancer aggressiveness, drug resistance, and tumor relapse. CD44, especially CD44v isoforms, have been identified as CSC surface markers for isolating and enriching CSCs in different types of cancers. The current findings concerning the critical role of CD44/CD44v in regulation of cancer stemness and the research status of CD44/CD44v as biomarkers and therapeutic targets in cancer are summarized. The current challenges and future directions that may lead to best use of CD44/CD44v for clinical applications are also discussed.

Mesenchymal stem cells (MSCs) have the capacity to restore liver function by differentiating into hepatocyte like cells. However, the underlying mechanisms are not well understood. Here, we have investigated the signals involved in the hepatic differentiation of human umbilical cord-derived mesenchymal stem cells (hUCMSCs). hUCMSCs were treated with mouse fetal liver-conditioned medium (FLCM) to induce hepatic differentiation. Flow cytometry, reverse transcription PCR, real-time PCR, immunocytochemistry, and polymerase chain reaction (PCR) array were used to detect the expression of MSC- and hepotocyte-specific markers in FLCM-treated hUCMSCs. Urea production and cytochrome P450 3A4 (CYP3A4) activity were used as indicators to evaluate liver cell characteristics. Raf/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) was analyzed in hUCMSCs by Western blotting. Following FLCM treatment, expression of MSC-specific markers decreased, while hepatocyte-specific gene expression was increased. Urea production, albumin secretion, glycogen storage, and CYP3A4 activity were significantly enhanced in FLCM-treated cells. In addition, ERK1/2 phosphorylation was increased in a time-dependent manner through Raf/MEK/ERK pathway, and phosphorylation was sustained at a high level during hepatic induction. Inhibition of ERK1/2 activation by U0126 (an ERK1/2 inhibitor) and pFLAG-CMV-ERK1(K71R) (negative mutant of ERK1) reversed the expression of liver-specific genes in hUCMSCs and affected hepatic function significantly. In summary, this work shows that ERK1/2 phosphorylation plays an important role in inducing hepatic differentiation of hUCMSCs in FLCM.

Acute kidney injury (AKI) is a common and serious medical condition associated with poor health outcomes. Autophagy is a conserved multistep pathway that serves a major role in many biological processes and diseases. Recent studies have demonstrated that autophagy is induced in proximal tubular cells during AKI. Autophagy serves a pro‑survival or pro‑death role under certain conditions. Furthermore, mesenchymal stem cells (MSCs) have therapeutic potential in the repair of renal injury. This review summarizes the recent progress on the role of autophagy in AKI and MSCs‑based therapy for AKI. Further research is expected to prevent and treat acute kidney injury.

Background aims On the basis of previous studies, exosomes secreted by human umbilical cord mesenchymal stromal cell (hucMSC-ex) could prevent and repair acute kidney injury induced by cisplatin in rats. However, its potential mechanism is still unclear. In the present study, the model with hucMSC-ex pretreated human renal tubular epithelial cell lines HK-2 that could prevent the injury of cisplatin was successfully established. Methods First, we pretreated the HK-2 cells with hucMSC-ex for 24 h. Cisplatin was then used to injure HK-2 cells. Gain and loss of function study were used to explore the role of 14-3-3ζ. The expression level of proliferating cell nuclear antigen (PCNA) was analyzed by immunofluorescence assay and Western blot. The number of apoptotic cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling assay and flow cytometry analysis. The formation of autophagosomes was observed under super-resolution optical microscope. Western blot was used to analyze the expression levels of LC3B, P62, 14-3-3ζ and Bax. Results Pretreating cells with hucMSC-ex could prevent the injury of cisplatin by reducing the number of apoptotic cells and increasing the expression level of PCNA. Simultaneously, the autophagic level was up-regulated. The application of autophagic inhibitor 3-methyladenine (3-MA) could reverse the protective effect of hucMSC-ex. The overexpression of 14-3-3ζ enhanced the autophagic level and protected the injury of cisplatin. The knock-down of 14-3-3ζ could reduce the autophagic level and enhance the disadvantage of cisplatin. The enhanced injury of cisplatin was reversed when the knock-down of 14-3-3ζ was replenished with hucMSC-ex. Conclusions 14-3-3ζ transported by hucMSC-ex may up-regulate autophagic level in HK-2 cells, which can prevent the injury of cisplatin. This discovery provides the new theoretical basis for the prevention of cisplatin-induced nephrotoxicity by hucMSC-ex.

To investigate the role of human umbilical cord mesenchymal stem cells (hucMSCs) in the treatment of dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD). ICG-hucMSCs homed to colon tissues of IBD mice 12 h after injection. The injection of hucMSCs significantly relieved the IBD symptoms and inflammatory cell infiltration. The expression of IL-10 gene increased while those of 15-LOX-1, TNF-α, IL-6, IL-1β, and IP-10 genes decreased in colon tissues and spleens of hucMSCs-treated mice. The activation of STAT3 was inhibited in colon tissues and spleens of IBD mice that were treated with hucMSCs. In addition, the percentage of macrophages decreased in colon tissues and spleens of hucMSCs-treated IBD mice. Moreover, we provided evidence that in vitro co-culture with hucMSCs inhibited the expression of 15-LOX-1, IL-6 and p-STAT3 in mouse enterocoelia macrophages. HucMSCs alleviate DSS-induced IBD through the modulation of 15-LOX-1 in macrophages.

hucMSC-Ex can activate autophagy in vitro. Quantitative RT-PCR analyses of ATG5 (A) and ATG7 (B) mRNA levels in NRK-52E cells. *P

Characterization of hucMSC-derived exosomes. (A) Nanoparticle tracking analysis on characteristics of the particles of hucMSC-Ex: (a) particle size and concentration, (b) the relative-intensity three-dimensional plot, (c) substantial shape of exosomes. (B) The morphology of hucMSC-Ex was observed under transmission electron microscopy (scale bar = 100 nm). (C) Western blotting analyses of the expression of exosomal markers CD81, CD9, and CD63 in hucMSC-Ex. (D) TUNEL assay was performed to detect the apoptotic cells (200×, scale bar = 50 μm). (E) Electron microscope analyses of the expression of exosomal markers CD9 colloidal gold in hucMSC-Ex (scale bar = 500 nm). (PDF 228 kb)