Effect of local injection of mesenchymal stem cells on healing of sutured gastric perforation in an experimental model

Adipose-Derived Stem Cells Prevent Anastomotic Leak: A Porcine Ischemic Esophagectomy Model

INTRODUCTION

Esophagectomy is a lifesaving procedure plagued by an anastomotic leak rate of 11%-35%. Ischemia is widely accepted to be the most significant risk factor for anastomotic leak. We hypothesized that the injection of adipose-derived stem cells (ASCs) into an ischemic esophagogastric anastomosis would prevent leakage.

METHODS

We developed a leaking ischemic esophagogastric anastomosis model in pigs using indocyanine green and the Elevision device to quantify perfusion. Anastomoses created using a gastric conduit with a relative perfusion of 50%-60% produced an anastomosis that consistently leaked (n = 3) compared to nonischemic controls (n = 3). We then injected either human (n = 2) or porcine (n = 2) ASCs around an ischemic anastomosis. We analyzed clinical outcomes including postoperative sepsis, weight loss, and disruption of the anastomosis and histopathology as well as immunohistochemistry.

RESULTS

All of the ischemic controls (3/3, 100%), as well as the xenograft human ASC-injected experimental group (2/2, 100%), became septic postoperatively and were found to have an anastomotic breakdown or disruption on necropsy. However, in the porcine allograft ASC-injected experimental group, the animals did well, with none of the subjects experiencing postoperative sepsis, and none were found to have disrupted anastomoses on necropsy. Histopathology revealed improved apposition of the anastomosis and immunohistochemistry revealed improved epithelization and submucosal fibrosis of the porcine ASC group compared to ischemic and human ASC groups.

CONCLUSIONS

Allogenic ASCs prevented anastomotic leakage of esophagogastric anastomosis in a porcine ischemic esophagectomy model.

Human umbilical mesenchymal stem cells ameliorate atrophic gastritis in aging mice by participating in mitochondrial autophagy through Ndufs8 signaling

BACKGROUND

Chronic atrophic gastritis (CAG) is a chronic disease of the gastric mucosa characterized by a reduction or an absolute disappearance of the original gastric glands, possibly replaced by pseudopyloric fibrosis, intestinal metaplasia, or fibrosis. CAG develops progressively into intestinal epithelial metaplasia, dysplasia, and ultimately, gastric cancer. Epidemiological statistics have revealed a positive correlation between the incidence of CAG and age. Mesenchymal stem cells (MSCs) are a type of adult stem cells derived from mesoderm, with strong tissue repair capabilities. Therefore, the restoration of the gastric mucosa may serve as an efficacious strategy to ameliorate CAG and avert gastric cancer. However, the mechanisms by which MSCs inhibit the relentless progression of aging atrophic gastritis remain to be elucidated. This study endeavored to assess a novel approach utilizing MSCs to treat CAG and forestall carcinogenics.

METHODS

In this study, we selected mice with atrophic gastritis from naturally aging mice and administered human umbilical cord-derived mesenchymal stem cells (hUMSCs) via tail vein injection to evaluate the therapeutic effects of hUMSCs on age-related chronic atrophic gastritis. Initially, we employed methods such as ELISA, immunohistochemical analysis, and TUNEL assays to detect changes in the mice post-hUMSC injection. Proteomic and bioinformatics analyses were conducted to identify differentially expressed proteins, focusing on NADH: ubiquinone oxidoreductase core subunit S8 (Ndufs8). Co-culturing hUMSCs with Ndufs8 knockout gastric mucosal epithelial cells (GMECs), we utilized flow cytometry, Western blotting, real-time quantitative PCR, and immunofluorescence to investigate the mechanisms of action of hUMSCs.

RESULTS

We observed that hUMSCs are capable of migrating to and repairing damaged gastric mucosa. Initially, hUMSCs significantly enhanced the secretion of gastric proteins PG-1 and G17, while concurrently reducing inflammatory cytokines. Furthermore, hUMSCs mitigated gastric fibrosis and apoptosis in mucosal cells. Proteomic and bioinformatic analyses revealed alterations in the protein network involved in mitochondrial autophagy, with Ndufs8 playing a pivotal role. Upon knocking out Ndufs8 in GMECs, we noted mitochondrial damage and reduced autophagy, leading to an aged phenotype in GMECs. Co-culturing Ndufs8-knockout GMECs with hUMSCs demonstrated that hUMSCs could ameliorate mitochondrial dysfunction and restore the cell cycle in GMECs.

Mesenchymal stem cells suppress inflammation by downregulating interleukin-6 expression in intestinal perforation animal model

Introduction

Intestinal perforation has significant fatality due to sepsis contamination and prolonged inflammation. Studies showed that mesenchymal stem cells (MSCs) secreted cytokines and growth factors to reduce inflammation. This study aims to reveal the role of MSCs in controlling inflammation in intestinal perforation wound healing by measuring interleukin-6 (IL-6) and leukocytes in injured tissue.

Materials and methods

A total of 48 rat models with a 10-mm longitudinal incision at the small intestine were divided into four groups: sham, control, Treatment group 1 (T1) injected with MSC doses of 1.5×106 cells and Treatment group 2 (T2) with 3×106 cells. IL-6 expressions were determined using western blot analysis, whereas the leukocyte infiltrations were assessed using the histopathological examination. All variables were evaluated on day 3 and 7.

Results

Leukocyte infiltration is significantly lower in T1 and T2 compared to control group in day 3 and 7 (P<0.05), while there were no differences between the two treatment groups. The expression of IL-6 was found to be significantly lower in the T1 and T2 groups compared to the control group on days 3 and 7 (P<0.05), with no significant differences observed between the two treatment groups.

Conclusion

MSCs administration in rats with intestinal perforation reduced inflammation by controlling leukocyte infiltration and IL-6 expression.

Prospective therapeutic targets and recent advancements in the treatment of inflammatory bowel disease

OBJECTIVE

Inflammatory Bowel Disease (IBD) poses a persistent challenge in the realm of gastroenterology, necessitating continual exploration of innovative treatment strategies. The limited efficacy and potential side effects associated with existing therapeutic modalities underscore the urgent need for novel approaches in IBD management. This study aims to examine potential therapeutic targets and recent advancements in understanding the disease's intricate pathogenesis, with a spotlight on the gut microbiome, immune dysregulation, and genetic predispositions.

METHODS

A comprehensive review was conducted to delve into the pressing demand for new avenues in IBD treatment. The study examined potential therapeutic targets such as phosphodiesterase 4 (PDE4) inhibitors, immune system modulators, Tyrosine kinase receptors (TYK), Toll-like receptors (TLRs), modulation of the gut microbiota, stem cell therapy, fibrosis management, interleukins (ILs) regulation, and oxidative stress mitigation. Additionally, advances in precision medicine, biologics, small molecule inhibitors, and microbiome modulation techniques were explored.

RESULTS

The investigation unveiled promising therapeutic targets and provided insights into recent breakthroughs that herald a transformative era in the therapeutic landscape for IBD. Advances in precision medicine, biologics, small molecule inhibitors, and the exploration of microbiome modulation techniques stood out as pivotal milestones in the field of gastroenterology.

CONCLUSIONS

The findings offer renewed hope for enhanced efficacy, reduced side effects, and improved patient outcomes in the treatment of IBD. These innovative approaches necessitate continual exploration and underscore the urgent need for novel strategies in IBD management, potentially revolutionizing the realm of gastroenterology.

Combined effect of pantoprazole and mesenchymal stem cells on experimentally induced gastric ulcer: implication of oxidative stress, inflammation and apoptosis pathways

Gastric ulcer (GU) is one of the most common diseases of the upper gastrointestinal tract that affects millions of people worldwide. This study aimed to investigate the possible alleviating effect of a combined treatment of pantoprazole (PANTO) and adipose tissue-derived mesenchymal stem cells (ADSCs) in comparison with each treatment alone on the healing process of the experimentally induced GU in rats, and to uncover the involved pathways. Rats were divided into five groups: (1) Control, (2) GU, (3) PANTO, (4) ADSCs and (5) ADSCs + PANTO. Markers of oxidative stress, inflammation and apoptosis were assessed. The current data indicated that PANTO-, ADSCs- and ADSCs + PANTO-treated groups showed significant drop (p < 0.05) in serum advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEPs) along with significant elevation (p < 0.05) in serum TAC versus the untreated GU group. Moreover, the treated groups (PANTO, ADSCs and ADSCs + PANTO) displayed significant down-regulation (p < 0.05) in gastric nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), intercellular adhesion molecule-1 (ICAM-1), matrix metallopeptidase 9 (MMP-9) and caspase-3 along with significant up-regulation (p < 0.05) in vascular endothelial growth factor (VEGF) and peroxisome proliferator-activated receptor gamma (PPARγ) genes expression compared to the untreated GU group. Immunohistochemical examination of gastric tissue for transforming growth factor β1 (TGF-β1), epidermal growth factor (EGF) and proliferating cell nuclear antigen (PCNA) showed moderate to mild and weak immune reactions, respectively in the PANTO-, ADSCs- and ADSCs + PANTO-treated rat. Histopathological investigation of gastric tissue revealed moderate to slight histopathological alterations and almost normal histological features of the epithelial cells, gastric mucosal layer, muscularis mucosa and submucosa in PANTO-, ADSCs- and ADSCs + PANTO-treated rats, respectively. Conclusively, the co-treatment with ADSCs and PANTO evidenced sententious physiological protection against GU by suppressing oxidative stress, inhibiting inflammation and reducing apoptosis with consequent acceleration of gastric tissue healing process.

Mesenchymal stem cells in craniofacial reconstruction: a comprehensive review

Craniofacial reconstruction faces many challenges, including high complexity, strong specificity, severe injury, irregular and complex wounds, and high risk of bleeding. Traditionally, the "gold standard" for treating craniofacial bone defects has been tissue transplantation, which involves the transplantation of bone, cartilage, skin, and other tissues from other parts of the body. However, the shape of craniofacial bone and cartilage structures varies greatly and is distinctly different from ordinary long bones. Craniofacial bones originate from the neural crest, while long bones originate from the mesoderm. These factors contribute to the poor effectiveness of tissue transplantation in repairing craniofacial defects. Autologous mesenchymal stem cell transplantation exhibits excellent pluripotency, low immunogenicity, and minimally invasive properties, and is considered a potential alternative to tissue transplantation for treating craniofacial defects. Researchers have found that both craniofacial-specific mesenchymal stem cells and mesenchymal stem cells from other parts of the body have significant effects on the restoration and reconstruction of craniofacial bones, cartilage, wounds, and adipose tissue. In addition, the continuous development and application of tissue engineering technology provide new ideas for craniofacial repair. With the continuous exploration of mesenchymal stem cells by researchers and the continuous development of tissue engineering technology, the use of autologous mesenchymal stem cell transplantation for craniofacial reconstruction has gradually been accepted and promoted. This article will review the applications of various types of mesenchymal stem cells and related tissue engineering in craniofacial repair and reconstruction.

Mesenchymal Stem Cells Accelerate Recovery of Acetic Acid-Induced Chronic Gastric Ulcer by Regulating Ekt/Akt/TRIM29 Axis

Chronic gastric ulcer (CGU), a prevalent digestive disease, has a high incidence and is seriously harmful to human health. Mesenchymal stem cells (MSCs) have been proven to have beneficial therapeutic effects in many human diseases. Here, a CGU model induced by acetic acid in mice was used to evaluate the repair effects and potential mechanism of human umbilical cord-derived MSCs (hUC-MSCs) and hUC-MSCs derived conditioned medium (hUC-MSC-CM). We found that hUC-MSCs and hUC-MSC-CM treatment significantly repaired morphological characteristics of CGU, improved proliferation and decreased apoptosis of gastric cells, and promoted the generation of new blood vessels in granulation tissues. In addition, we could detect the homing of MSCs in gastric tissue, and MSCs may differentiate into Lgr5-positive cells. As well as this, in vitro experiments showed that hUC-MSC-CM could promote cell proliferation, stimulate cell cycle progression, and reduce the incidence of apoptosis. The transcriptome of cells and the iTRAQ proteome of gastric tissues suggest that MSCs may play a therapeutic role by increasing the expression of TRIM29. Additionally, it was found that knocking down TRIM29 significantly decreased the ameliorative effects of hUC-MSC-CM on cell apoptosis. As a result of further molecular experiments, it was found that TRIM29 is capable of phosphorylating Erk/Akt in specific cell type. As a whole, it appears that hUC-MSCs can be an effective therapeutic approach for promoting gastric ulcer healing and may exert therapeutic effects in the form of paracrine and differentiation into gastric cells.

Lipoaspirate stored at a constant low temperature by electric control suppresses intracellular metabolism and maintains high cell viability

Background

Cell therapy is a useful treatment method for wide spectrum of diseases which utilizes the immunosuppressive and regenerative abilities of administered cells. It is essential to build a transport system of tissues from which cells are harvested, because various external factors, such as temperature, time, air pressure, and vibration affect the cell functions isolated from body tissues. In particular, temperature is a critical factor which determines the viability of the cells and organs. In this study, we investigated the optimal temperature during the transportation of lipoaspirates from which adipose -derived stem cells (ASCs) were isolated.

Method

Lipoaspirates obtained by liposuctions (lipomatic or vaser method) were transported in four different temperature zones (4, 20, 32, and 37 °C) in a transport container which is electrically controlled to maintain a constant temperature during transport. Stromal vascular fractions (SVFs) were harvested from the lipoaspirate, and the cell number, viability and proliferation rate and the yield of ASCs were examined. In addition, the metabolic state of the cells was examined.

Results

ASCs from lipoaspirates transported at high temperature significantly decreased cell viability, while those at low temperature maintained high cell viability and showed good cell proliferation. In addition, transportation of lipoaspirates at low temperature resulted in a high level of NAD+/NADH, coenzymes involved in intracellular metabolism, and a low level of lactate in lipoaspirate suppressed the glycolytic system of intracellular metabolism, in ASCs.

Conclusion

The lipoaspirate transported at 4 °C exhibited best results regarding live cell number, viability and cell proliferation in our experiments. This study offers a direction to build a transport system that connects laboratories and hospitals and achieve a beneficial therapy for patients.

Role of adipose-derived stem cells in healing surgically induced trauma of the rat's tunica albuginea

Background

Injection of adipose-derived stem cells (ADSCs) into the injured tunica albuginea (TA) may prevent fibrosis, restore the balance between pro- and antifibrotic pathways, and potentially mitigate erectile dysfunction caused by abnormal TA healing.

Aim

To assess the potential role of ADSC injection on structural, ultrastructural, functional, and molecular changes in surgically induced trauma of the rat's TA.

Methods

Forty adult male albino Wistar rats were divided into 5 groups of 8 rats each: group 1, sham; group 2, injury to TA without treatment; group 3, injury to TA and suture repair; group 4, injury to TA and injection of ADSCs without suture repair; group 5, injury to TA followed by injection of ADSCs and suture repair.

Outcomes

After 6 weeks, all groups were subjected to functional, histologic, and ultrastructural examination and molecular expression of healing growth factors.

Results

The intracavernous pressure (ICP; mean ± SD) was 114 ± 2, 32 ± 2, 65 ± 2, 68 ± 2, and 111 ± 2 mm Hg in groups 1 to 5, respectively. There were significant differences in ICP between each of groups 3 to 5 and group 2 (P < .05), and groups 3 and 4 each had significant differences with group 1 (P < .05). No significant difference in ICP occurred between groups 3 and 4 (P > .05). There were significant histologic and ultrastructural alterations in tunical tissues from group 2; however, these changes were markedly less in group 5 in terms of lower levels of fibrotic changes, elastosis, and superior overall neuroendothelial expression. Groups 3 and 4 showed improved structural and ultrastructural parameters when compared with group 2. Group 5 demonstrated lower levels of transforming growth factor β1 and basic fibroblast growth factor expression.

Clinical Implications

This experimental model may encourage administration of ADSCs to prevent the deleterious effects of trauma to the TA.

Strengths and Limitations

Injecting ADSCs can improve the healing process and erectile dysfunction in a rat model following TA injury, and combining ADSC injection with surgical suturing resulted in superior outcomes. The main limitation was the absence of long-term ICP measurements and a longer follow-up period that may provide further insight into the chronic phase of the healing process.

Conclusion

ADSC injection may prevent structural, ultrastructural, functional, and molecular alterations in surgically induced trauma of the rat's TA and enhance the effect of tunical suturing after trauma.

Adipose-derived human mesenchymal stem cells seeded on denuded or stromal sides of the amniotic membrane improve angiogenesis and collagen remodeling and accelerate healing of the full-thickness wound

Several strategies have been proposed to enhance wound healing results. Along with other forms of wound dressing, the human amniotic membrane (HAM) has long been regarded as a biological wound dressing that decreases infection and enhances healing. This study investigates the feasibility and effectiveness of wound healing using decellularized HAM (dAM) and stromal HAM (sAM) in combination with adipose-derived human mesenchymal stem cells (AdMSCs). The dAM and sAM sides of HAM were employed as wound dressing scaffolds, and AdMSCs were seeded on top of either dAM or sAM. Sixty healthy Wistar rats were randomly divided into three groups: untreated wound, dAM/AdMSCs group, and sAM/AdMSCs group. The gene expression of VEGF and COL-I was measured in vitro. Wound healing was examined after wounding on days 3, 7, 14, and 21. The expression level of VEGF was significantly higher in sAM/AdMSCs than dAM/AdMSCs (P ≤ 0.05), but there was no significant difference in COL-I expression (P ≥ 0.05). In vivo research revealed that on day 14, wounds treated with sAM/AdMSCs had more vascularization than wounds treated with dAM/AdMSCs (P ≤ 0.01) and untreated wound groups on days 7 (P ≤ 0.05) and 14 (P ≤ 0.0001), respectively. On days 14 (P < 0.05 for sAM/AdMSCs, P < 0.01 for dAM/AdMSCs), and 21 (P < 0.05 for sAM/AdMSCs, P < 0.01 for dAM/AdMSCs), the collagen deposition in the wound bed was significantly thicker in the sAM/AdMSCs and dAM/AdMSCs groups compared to untreated wounds. The study demonstrated that the combination of sAM and AdMSCs promotes wound healing by enhancing angiogenesis and collagen remodeling.

Local injection of adipose-derived mesenchymal stem cells in silk fibroin solution on the regeneration of lower esophageal sphincter in an animal model of GERD

Presently, various tissue engineering methods using adult stem cells and biomaterials are being confirmed to regenerate vessels, cardiac muscle, bladder, and intestines. However, there are few studies about the repair of the lower esophageal sphincter (LES) may help alleviate the symptoms of gastroesophageal reflux disease (GERD). This study aims to determine whether Adipose-Derived Stem Cells (ADSCs) combined with regenerated silk fibroin (RSF) solution could regenerate the LES. In vitro, the ADSCs were isolated, identified, and then cultured with an established smooth muscular induction system. In vivo, in the experimental groups, CM-Dil labeled ADSCs or induced ADSCs mixed with RSF solution were injected into the LES of rats after the development of the animal model of GERD respectively. The results showed that ADSCs could be induced into smooth muscular-like cells with the expression of h-caldesmon, calponin, α-smooth muscle actin, and a smooth muscle-myosin heavy chain in vitro. In vivo, the thickness of LES in the experiment rats was much thicker than those in the controlled groups. This result indicated that ADSCs mixed with RSF solution might contribute to the regeneration of the LES, thus reducing the occurrence of GERD.

Mesenchymal Stem Cell-Derived Exosomes Modulate Angiogenesis in Gastric Cancer

Individualized gastric cancer (GC) treatment aims at providing targeted therapies that translate the latest research into improved management strategies. Extracellular vesicle microRNAs have been proposed as biomarkers for GC prognosis. Helicobacter pylori infection influences the therapeutic response to and the drivers of malignant changes in chronic gastritis. The successful use of transplanted mesenchymal stem cells (MSCs) for gastric ulcer healing has raised interest in studying their effects on tumor neovascularization and in potential antiangiogenic therapies that could use mesenchymal stem cell secretion into extracellular vesicles—such as exosomes—in GC cells. The use of MSCs isolated from bone marrow in order to achieve angiogenic modulation in the tumor microenvironment could exploit the inherent migration of MSCs into GC tissues. Bone marrow-derived MSCs naturally present in the stomach have been reported to carry a malignancy risk, but their effect in GC is still being researched. The pro- and antiangiogenic effects of MSCs derived from various sources complement their role in immune regulation and tissue regeneration and provide further understanding into the heterogeneous biology of GC, the aberrant morphology of tumor vasculature and the mechanisms of resistance to antiangiogenic drugs.

Polydopamine-modified decellularized intestinal scaffolds loaded with adipose-derived stem cells promote intestinal regeneration

Regeneration of gastrointestinal tissues remains a great challenge due to their unique microenvironment. Functional composite decellularized scaffolds have shown great potential in gastrointestinal repair and inducing gastrointestinal tissue-specific proliferation. In this study, polydopamine (PDA)-mediated surface modification of decellularized intestinal scaffolds (DIS), combined with adipose tissue-derived stem cells (ADSC), was used to promote intestinal wound healing while avoiding intestinal resection. The results showed that DIS had good biocompatibility and could maintain the growth and proliferation of ADSC. Moreover, PDA-coated DIS not only had anti-infection ability but could also further promote the secretory activity for the paracrine effects of ADSC. ADSC cultured on PDA-DIS produced significantly higher levels of anti-inflammatory and proangiogenic cytokines than those cultured on plastic plates or DIS. In vivo, ADSC-PDA-DIS significantly promoted intestinal wound closure in rat intestinal defect models. Moreover, ADSC-PDA-DIS was able to induce more neovascularization at 4 weeks postoperatively and promoted macrophage recruitment to accelerate wound healing. Taken together, the results showed that PDA-modified DIS could significantly improve the efficacy of stem cell therapy, and ADSC-PDA-DIS could improve the wound healing process with anti-infection effects, enhancing neovascularization and immunoregulation, which may be of great clinical significance for gastrointestinal regeneration.

Locally injected Mesenchymal Stem Cells optimize angiogenesis by regulating VEGF and CD31 expression in duodenal perforation

Background

Duodenal perforation is considered as one of gastrointestinal emergency with high morbidity and mortality rate. The MSCs have the ability to improve wound healing by releasing several growth factors and anti-inflammatory cytokines to promote the angiogenesis process. This study aimed to investigate the role of MSCs in duodenal perforation wound healing.

Methods

MSCs were isolated from rat umbilical cord and injected into duodenal wound site at doses of 1.5x10 [(Putra et al., 2018) 66 cells for T1 group and 3x10 [(Putra et al., 2018) 66 cells for T2 group. The control group was treated by local injection of normal saline. The VEGF levels were measured by Western blot, while CD31 expression was analyzed using immunohistochemistry staining. All examinations were assessed on days 3 and 7.

Results

Results showed a significant increase in VEGF and CD31 expression on days 3 and 7 (p < 0,05). The VEGF level was significantly decreased on day 7 compared to day 3.

Conclusion

The administration of MSCs improved the angiogenesis process in duodenal perforation by enhancing VEGF and CD31 expression.

•

Duodenal perforation is considered as one of gastrointestinal emergency with high morbidity and mortality rate.

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The MSCs have the ability to improve wound healing by releasing several growth factors and anti-inflammatory cytokines to promote the angiogenesis process.

•

This study aimed to investigate the role of MSCs in duodenal perforation wound healing.

•

Results showed a significant increase in VEGF and CD31 expression on days 3 and 7.

•

The administration of MSCs improved the angiogenesis process in duodenal perforation.

Stem cell therapy applied for digestive anastomosis: Current state and future perspectives

BACKGROUND

Digestive tract resections are usually followed by an anastomosis. Anastomotic leakage, normally due to failed healing, is the most feared complication in digestive surgery because it is associated with high morbidity and mortality. Despite technical and technological advances and focused research, its rates have remained almost unchanged the last decades. In the last two decades, stem cells (SCs) have been shown to enhance healing in animal and human studies; hence, SCs have emerged since 2008 as an alternative to improve anastomoses outcomes.

AIM

To summarise the published knowledge of SC utilisation as a preventative tool for hollow digestive viscera anastomotic or suture leaks.

METHODS

PubMed, Science Direct, Scopus and Cochrane searches were performed using the key words "anastomosis", "colorectal/colonic anastomoses", "anastomotic leak", "stem cells", "progenitor cells", "cellular therapy" and "cell therapy" in order to identify relevant articles published in English and Spanish during the years of 2000 to 2021. Studies employing SCs, performing digestive anastomoses in hollow viscera or digestive perforation sutures and monitoring healing were finally included. Reference lists from the selected articles were reviewed to identify additional pertinent articles.Given the great variability in the study designs, anastomotic models, interventions (SCs, doses and vehicles) and outcome measures, performing a reliable meta-analysis was considered impossible, so we present the studies, their results and limitations.

RESULTS

Eighteen preclinical studies and three review papers were identified; no clinical studies have been published and there are no registered clinical trials. Experimental studies, mainly in rat and porcine models and occasionally in very adverse conditions such as ischaemia or colitis, have been demonstrated SCs as safe and have shown some encouraging morphological, functional and even clinical results. Mesenchymal SCs are mostly employed, and delivery routes are mainly local injections and cell sheets followed by biosutures (sutures coated by SCs) or purely topical. As potential weaknesses, animal models need to be improved to make them more comparable and equivalent to clinical practice, and the SC isolation processes need to be standardised. There is notable heterogeneity in the studies, making them difficult to compare. Further investigations are needed to establish the indications, the administration system, potential adjuvants, the final efficacy and to confirm safety and exclude definitively oncological concerns.

CONCLUSION

The future role of SC therapy to induce healing processes in digestive anastomoses/sutures still needs to be determined and seems to be currently far from clinical use.

Therapeutic approach of adipose-derived mesenchymal stem cells in refractory peptic ulcer

Peptic ulcer is one of the most common gastrointestinal tract disorders worldwide, associated with challenges such as refractory morbidity, bleeding, interference with use of anticoagulants, and potential side effects associated with long-term use of proton pump inhibitors. A peptic ulcer is a defect in gastric or duodenal mucosa extending from muscularis mucosa to deeper layers of the stomach wall. In most cases, ulcers respond to standard treatments. However, in some people, peptic ulcer becomes resistant to conventional treatment or recurs after initially successful therapy. Therefore, new and safe treatments, including the use of stem cells, are highly favored for these patients. Adipose-derived mesenchymal stem cells are readily available in large quantities with minimal invasive intervention, and isolation of adipose-derived mesenchymal stromal stem cells (ASC) produces large amounts of stem cells, which are essential for cell-based and restorative therapies. These cells have high flexibility and can differentiate into several types of cells in vitro. This article will investigate the effects and possible mechanisms and signaling pathways of adipose tissue-derived mesenchymal stem cells in patients with refractory peptic ulcers.

Human Adipose Derived Stem Cells Enhance Healing in a Rat Model of Esophageal Injury with Stent

BACKGROUND

Mesenchymal stem cells have been proven to promote cellular recruitment and remodeling during healing. Considering challenges encountered in the healing process of esophageal injury, we sought to evaluate the effect of human adipose derived stem cells (hASC) on esophageal injury with stent and to assess the feasibility of submucosal hASC injection as a mechanism of delivery.

METHODS

An intrabdominal esophagotomy was created in rodents with placement of an expandable fully covered metal esophageal stent. A submucosal injection of 2 × 10⁶ hASC was delivered in experimental animals. Animals were sacrificed on postoperative day 3 (POD3) or 7 (POD7). Macroscopic, immunohistochemical and immunofluorescence analyses were conducted to assess for markers of healing and viability of transplanted cells.

RESULTS

hASC were identified within submucosal and muscular layers with proliferation demonstrated in respective areas on anti-Ki67 stained sections. Lower adhesion and abscess scores were observed in hASC specimens without significant statistical difference. Prevalence of submucosal collagen was increased in samples treated with hASC compared to control, with abundant collagen deposition demonstrated within the POD7 group. Granulation tissue at the site of esophageal injury was more prominent in tissue sections treated with hASC compared to control, with significantly higher density at POD3 (control 1.94 versus hASC 2.83, P < 0.01).

CONCLUSIONS

Presence of hASC at the site of an esophageal injury may enhance wound healing predominantly through increased granulation and decreased inflammation in conjunction with esophageal stent placement. Targeted submucosal injection at the time of esophageal stent placement is an effective delivery method of hASC therapy.

Ultrafast self-gelling powder mediates robust wet adhesion to promote healing of gastrointestinal perforations

Achieving strong adhesion of bioadhesives on wet tissues remains a challenge and an acute clinical demand because of the interfering interfacial water and limited adhesive-tissue interactions. Here we report a self-gelling and adhesive polyethyleneimine and polyacrylic acid (PEI/PAA) powder, which can absorb interfacial water to form a physically cross-linked hydrogel in situ within 2 seconds due to strong physical interactions between the polymers. Furthermore, the physically cross-linked polymers can diffuse into the substrate polymeric network to enhance wet adhesion. Superficial deposition of PEI/PAA powder can effectively seal damaged porcine stomach and intestine despite excessive mechanical challenges and tissue surface irregularities. We further demonstrate PEI/PAA powder as an effective sealant to enhance the treatment outcomes of gastric perforation in a rat model. The strong wet adhesion, excellent cytocompatibility, adaptability to fit complex sites, and easy synthesis of PEI/PAA powder make it a promising bioadhesive for numerous biomedical applications.

Endoscopic atomization of mesenchymal stromal cells: in vitro study for local cell therapy of the lungs

BACKGROUND AIMS

Cell-based therapies of pulmonary diseases with mesenchymal stromal cells (MSCs) are increasingly under experimental investigation. In most of these, MSCs are administered intravenously or by direct intratracheal instillation. A parallel approach is to administer the cells into the lung by endoscopic atomization (spraying). In a previous study, the authors developed a flexible endoscopic atomization device that allows administration of respiratory epithelial cells in the lungs with high survival.

METHODS

In this study, the authors evaluated the feasibility of spraying MSCs with two different endoscopic atomization devices (air and pressure atomization). Following atomization, cell viability was evaluated with live/dead staining. Subsequent effects on cytotoxicity, trilineage differentiation and expression of MSC-specific markers as well as on MSC metabolic activity and morphology were analyzed for up to 7 days.

RESULTS

MSC viability immediately after spraying and subsequent metabolic activity for 7 days was not influenced by either of the devices. Slightly higher cytotoxicity rates could be observed for pressure-atomized compared with control and air-atomized MSCs over 7 days. Flow cytometry revealed no changes in characteristic MSC cell surface marker expression, and morphology remained unchanged. Standard differentiation into osteocytes, chondrocytes and adipocytes was inducible after atomization.

CONCLUSIONS

In the literature, a minimal survival of 50% was previously defined as the cutoff value for successful cell atomization. This is easily met with both of the authors' devices, with more than 90% survival. Thus, there is a potential role for atomization in intrapulmonary MSC-based cell therapies, as it is a feasible and easily utilizable approach based on clinically available equipment.

Mesenchymal stem cells promote healing of nonsteroidal anti-inflammatory drug-related peptic ulcer through paracrine actions in pigs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most important causes of peptic ulcer disease in high-income countries. Proton pump inhibitors are the current standard treatment; however, safety and long-term adverse effects of using these drugs are attracting more and more concerns in recent years. Using a porcine model of NSAID-related gastric ulcer, we herein show that adipose-derived mesenchymal stem cells (ADMSCs) delivered by endoscopic submucosal injection promoted ulcer healing with less inflammatory infiltration and enhanced reepithelization and neovascularization at day 7 and day 21 when compared with the controls (saline injection). However, only few engrafted ADMSCs showed myofibroblast and epithelial cell phenotype in vivo, suggesting the ulcer healing process might be much less dependent on the stem cell transdifferentiation. Further experiment with submucosal injection of MSC-derived secretome revealed a therapeutic efficacy comparable to that of stem cell transplantation. Profiling analysis showed up-regulation of genes associated with inflammation, granulation formation, and extracellular matrix remodeling at day 7 after injection of MSC-derived secretome. In addition, the extracellular signal-regulated kinase/mitogen-activated protein kinase and the phosphoinositide-3-kinase/protein kinase B pathways were activated after injection of ADMSCs or MSC-derived secretome. Both signaling pathways were involved in mediating the major events critical to gastric ulcer healing, including cell survival, migration, and angiogenesis. Our data suggest that endoscopic submucosal injection of ADMSCs serves as a promising approach to promote healing of NSAID-related peptic ulcer, and the paracrine effectors released from stem cells play a crucial role in this process.

Ameliorated healing of biliary anastomosis by autologous adipose-derived stem cell sheets

INTRODUCTION

Cell sheets consisting of adipose-derived stem cells (ADSCs) have been reported to be effective for wound healing. We conducted this study to clarify the efficacy of ADSC sheets in wound healing at the duct-to-duct biliary anastomotic site in pigs.

METHODS

Eleven female pigs (20-25 kg) were divided into two groups: biliary anastomosis with an ADSC sheet (n = 6) or without an ADSC sheet (n = 5). To follow the transplanted ADSCs, PKH26GL-labeled sheets were used in one of the ADSC pigs. Two weeks prior to laparotomy, ADSCs were isolated from the lower abdominal subcutaneous adipose tissue. After three passages, ADSCs were seeded on temperature-responsive culture dishes and collected as cell sheets. ADSC sheets were gently transplanted on the anastomotic site. We evaluated specimens by PKH26GL labeling, macroscopic changes, infiltration of inflammatory cells, and collagen content.

RESULTS

Labeled ADSCs remained around the bile duct wall. In the no-ADSC group, more adhesion developed at the hepatic hilum as observed during relaparotomy. Histopathological examination showed that the diameter and cross-sectional area of the bile duct wall were decreased in the ADSC group. In the no-ADSC group, a large number of inflammatory cells and more collagen fibers were identified in the bile duct wall.

CONCLUSIONS

The present study demonstrated that autologous ADSC sheet transplantation reduced hypertrophic changes in the bile duct wall at the anastomotic site. A long-term follow-up is required to evaluate the efficacy of this mechanism in prevention of biliary anastomotic strictures.

Microskin-Inspired Injectable MSC-Laden Hydrogels for Scarless Wound Healing with Hair Follicles

Scarless skin regeneration with functional tissue remains a challenge for full-thickness wounds. Here, mesenchymal stem cell (MSC)-laden hydrogels are developed for scarless wound healing with hair follicles. Microgels composed of aligned silk nanofibers are used to load MSCs to modulate the paracrine. MSC-laden microgels are dispersed into injectable silk nanofiber hydrogels, forming composites biomaterials containing the cells. The injectable hydrogels protect and stabilize the MSCs in the wounds. The synergistic action of silk-based composite hydrogels and MSCs stimulated angiogenesis and M1-M2 phenotype switching of macrophages, provides a suitable niche for functional recovery of wounds. Compared to skin defects treated with MSC-free hydrogels, the defects treated with the MSC-laden composite hydrogels heal faster and form scarless tissues with hair follicles. Wound healing can be further improved by adjusting the ratio of silk nanofibers and particles and the loaded MSCs, suggesting tunability of the system. To the best of current knowledge, this is the first time scarless skin regeneration with hair follicles based on silk material systems is reported. The improved wound healing capacity of the systems suggests future in vivo studies to compare to other biomaterial systems related to clinical goals in skin regeneration in the absence of scarring.

Enhanced Effect of IL-1β-Activated Adipose-Derived MSCs (ADMSCs) on Repair of Intestinal Ischemia-Reperfusion Injury via COX-2-PGE2 Signaling

Adipose-derived mesenchymal stem cells (ADMSCs) have been used for treating tissue injury, and preactivation enhances their therapeutic effect. This study is aimed at investigating the therapeutic effect of activated ADMSCs by IL-1β on the intestinal ischaemia-reperfusion (IR) injury and exploring potential mechanisms. ADMSCs were pretreated with IL-1β in vitro, and activation of ADMSCs was assessed by α-SMA and COX-2 expressions and secretary function. Activated ADMSCs was transplanted into IR-injured intestine in a mouse model, and therapeutic effect was evaluated. In addition, to explore underlying mechanisms, COX-2 expression was silenced to investigate its role in activated ADMSCs for treatment of intestinal IR injury. When ADMSCs were pretreated with 50 ng/ml IL-1β for 24 hr, expressions of α-SMA and COX-2 were significantly upregulated, and secretions of PGE₂, SDF-1, and VEGF were increased. When COX-2 was silenced, the effect of IL-1β treatment was abolished. Activated ADMSCs with IL-1β significantly suppressed inflammation and apoptosis and enhanced healing of intestinal IR injury in mice, and these effects were impaired by COX-2 silencing. The results of RNA sequencing suggested that compared with the IR injury group activated ADMSCs induced alterations in mRNA expression and suppressed the activation of the NF-κB-P65, MAPK-ERK1/2, and PI3K-AKT pathways induced by intestinal IR injury, whereas silencing COX-2 impaired the suppressive effect of activated ADMSCs on these pathway activations induced by IR injury. These data suggested that IL-1β pretreatment enhanced the therapeutic effect of ADMSCs on intestinal IR injury repairing via activating ADMSC COX-2-PGE₂ signaling axis and via suppressing the NF-κB-P65, MAPK-ERK1/2, and PI3K-AKT pathways in the intestinal IR-injured tissue.

Myofibroblasts Enhance Tumor Growth in a Novel Mouse Model of Colorectal Cancer

BACKGROUND

Communication between colorectal cancer and stromal cells alters the tumor microenvironment to regulate locoregional disease and cancer progression. However, colon cancer-stromal cell interactions are difficult to study in vivo. Limitations of existing animal models include the use of immunocompromised mice, the inability to genetically modify a cell population in a single organ system, or a lack of anatomic context. Our goal was to develop a novel mouse model of colorectal cancer that is capable of studying tumor-stromal cell interactions in the native colon of immune-competent mice.

METHODS

Primary mouse myofibroblasts were isolated from the colon of C57BL/6 mice and were grown in cell culture. Genetically defined (ApcΔ/Δ; Kras ^G12D/+; Trp53Δ/Δ) primary mouse colon cancer cells were suspended in serum-free media (20 μL) at varying concentrations (5 × 10³ to 4 × 10⁴ cells) either alone or in combination with syngeneic myofibroblasts (2 × 10⁵ cells). After isoflurane anesthesia, a colonoscopy was performed on immune-competent 8- to 10-week-old C57BL/6 mice with endoscopic microinjection of the cell suspension into the submucosal space of the colon wall utilizing a small animal colonoscope. Surveillance endoscopy was used to assess for tumor growth, along with histologic analysis. Tumor size is presented on a grading system based on tumor diameter relative to colon circumference.

RESULTS

A total of 33 mice were injected with a survival rate of 88% (29/33). Endoscopic microinjection of colorectal cancer cells resulted in dose-dependent tumor growth in the distal mouse colon that could be assessed endoscopically without animal sacrifice. Growth curves varied depending on the concentration of injected colorectal cancer cells, with no growth at the lowest concentration of injected cells (5 × 10³ cells), progressive growth over 4 wk using 1-2 × 10⁴ cells, while the highest colorectal cancer cell concentration (4 × 10⁴ cells) led to larger tumors at week 1 followed by a steady decline in tumor growth over the 4-wk time period. Combined microinjection of 2 × 10⁴ colorectal cancer cells with 2 × 10⁵ myofibroblasts resulted in much larger tumors that persisted over the 4-wk time period and which were composed primarily of colorectal cancer cells. Immunofluorescence microscopy after coinjection of colorectal cancer cells with green fluorescent protein positive myofibroblasts confirmed that the injected myofibroblasts are present and remain viable over the 4-wk time period.

CONCLUSIONS

Endoscopic submucosal microinjection of primary mouse colorectal cancer cells is feasible and leads to reliable and reproducible short-term growth of colon tumors in immune-competent mice. Coinjection of primary mouse colorectal cancer cells with syngeneic myofibroblasts leads to enhanced tumor growth. Coimplantation of colorectal cancer cells with syngeneic myofibroblasts provides a novel platform to study tumor-stromal interactions in the native colon of immune-competent mice.

Stem-Cell Therapy for Esophageal Anastomotic Leakage by Autografting Stromal Cells in Fibrin Scaffold

Esophageal anastomotic leakage (EAL) is a devastating complication for esophagectomy but the available therapies are unsatisfactory. Due to the healing effects of mesenchymal stromal cells (MSCs) and supporting capability of fibrin scaffold (FS), we evaluated the efficacy of a stem-cell therapy for EAL by engrafting adult and autologous MSCs (AAMSCs) in FS and investigated the potential mechanism. Twenty-one rabbits were assigned to AAMSC/FS group (n = 12) and control group (n = 9). After harvested, AAMSCs were identified and then labeled with lenti.GFP. To construct EAL model, a polyethylene tube was indwelled through the anastomosis for 1 week. A total of 2 × 106 AAMSCs in 0.2 ml FS were engrafted onto the EAL for the AAMSC/FS group, whereas FS was injected for control. Magnetic Resonance Imaging (MRI) examination was performed after 5 weeks. Esophageal tissues were harvested for macroscopic, histological analyses, Western blot, and immunohistochemistry at 8 weeks. The animal model of EAL was established successfully. MRI scanning revealed a decreased inflammation reaction in AAMSC/FS group. Accordingly, AAMSC/FS group presented a higher closure rate (83.3% vs. 11.1%, p = .02) and lower infection rate (33.3% vs. 88.9%, p = .02). Histological analyses showed the autografted MSCs resided in the injection site. Furthermore, milder inflammation responses and less collagen deposition were observed in AAMSC/FS group. Western blot and immunohistochemistry studies suggested that the therapeutic effect might be related to the secretions of IL-10 and MMP-9. Engrafting AAMSCs in FS could be a promising therapeutic strategy for the treatment of EAL by suppressing inflammation response and alleviating fibrosis progression. Stem Cells Translational Medicine 2019;8:548-556.

The Clinical Trials of Mesenchymal Stem Cell Therapy in Skin Diseases: An Update and Concise Review

The skin is one of the crucial body organs with anatomy and physiology linked to various disorders including congenital and acquired diseases. Nowadays, mesenchymal stem cell (MSCs)- based therapy has appeared as a promising therapeutic field, in which many see opportunities to cure the costliest and incurable diseases. However, one question to be asked is that if the use of MSCs in clinical trials studies and diseases treatment has improved. In this study, the clinical trials using MSCs in skin diseases were reviewed. A remarkable number of clinical trial studies are in progress in this field; however, only a few of them have led to tangible benefits for patients. The relevant papers and ongoing clinical trials that address MSC's therapeutic goals for various skin disorders were examined. This review can be very useful for both the dermatologists and basic skin researchers interested in contributing to stem cell-based therapeutic researches in the area of skin disorders.

Adipose-Derived Mesenchymal Stromal Cells Improve the Healing of Colonic Anastomoses Following High Dose of Irradiation Through Anti-Inflammatory and Angiogenic Processes

Cancer patients treated with radiotherapy (RT) could develop severe late side effects that affect their quality of life. Long-term bowel complications after RT are mainly characterized by a transmural fibrosis that could lead to intestinal obstruction. Today, surgical resection is the only effective treatment. However, preoperative RT increases the risk of anastomotic leakage. In this study, we attempted to use mesenchymal stromal cells from adipose tissue (Ad-MSCs) to improve colonic anastomosis after high-dose irradiation. MSCs were isolated from the subcutaneous fat of rats, amplified in vitro, and characterized by flow cytometry. An animal model of late radiation side effects was induced by local irradiation of the colon. Colonic anastomosis was performed 4 wk after irradiation. It was analyzed another 4 wk later (i.e., 8 wk after irradiation). The Ad-MSC-treated group received injections several times before and after the surgical procedure. The therapeutic benefit of the Ad-MSC treatment was determined by colonoscopy and histology. The inflammatory process was investigated using Fluorine-182-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography and Computed Tomography (¹⁸F-FDG-PET/CT) imaging and macrophage infiltrate analyses. Vascular density was assessed using immunohistochemistry. Results show that Ad-MSC treatment reduces ulcer size, increases mucosal vascular density, and limits hemorrhage. We also determined that 1 Ad-MSC injection limits the inflammatory process, as evaluated through ¹⁸F-FDG-PET-CT (at 4 wk), with a greater proportion of type 2 macrophages after iterative cell injections (8 wk). In conclusion, Ad-MSC injections promote anastomotic healing in an irradiated colon through enhanced vessel formation and reduced inflammation. This study also determined parameters that could be improved in further investigations.

Experimental research on ADSCs-NCSS in wound repair

New collagen sponge scaffold (NCSS) combined with adipose-derived stem cells (ADSCs) in the repair of full-thickness skin wound in nude mice was investigated. Human ADSCs were extracted via enzyme digestion; NCSS materials were prepared using modified method; the tissue-engineered skin substitute was constructed using ADSCs combined with NCSS. Two 10 mm² full-thickness skin wounds were designed on the back of 24 female nude mice, respectively. Mice were divided into 4 groups in the experiment: ADSCs-NCSS (group A), simple NCSS (group B), simple ADSCs (group C) and blank control (group D). The wound healing rates were observed at 3, 7, 10 and 14 days after operation, and specimens were taken at 1 and 2 weeks for histological detection and immunohistochemical cluster of differentiation 31 (CD31) vascular density detection, respectively. At 3 and 7 days after construction of new tissue-engineered skin substitute, the infiltration of ADSCs could be seen within NCSS. The wound healing rates at 7, 10 and 14 days after operation in group A were (77.13±1.25%), (89.90±1.08%) and (96.08±0.6%), respectively, which were significantly higher than those in groups B-D; the differences were statistically significant (p<0.05). The detection of regenerated wound tissue thickness at 1 and 2 weeks after operation and CD31 vascular density at 1 week after operation showed that the vascular density in the wound in group A was significantly higher than those in other groups; the differences were statistically significant (p<0.05). After the transplantation of tissue-engineered skin constructed by human ADSCs combined with NCSS, the quality of wound healing in nude mice can be significantly improved, and the wound repair can be promoted.

Secretome from hypoxia-conditioned adipose-derived mesenchymal stem cells promotes the healing of gastric mucosal injury in a rodent model

Studies have indicated that the definitive engraftment and transdifferentiation potential of stem cells do not seem crucial for its property of tissue repair. Our previous study showed that transplantation of adipose-derived mesenchymal stem cells (ADMSCs) enhanced the healing of sutured gastric perforation. This study aimed to investigate the paracrine role of ADMSCs in the experimental gastric mucosal injury. Normoxia-conditioned medium (Nor CM) and hypoxia (HPO) CM were obtained after culturing ADMSCs in 20% O₂ and 5% O₂ for 48h. Cell migration, proliferation, viability, and angiogenesis in vitro were significantly enhanced upon incubation with CM, especially the HPO CM. Experiments in vivo using a rodent model of gastric ulcer demonstrated that HPO CM treatment significantly accelerated wound healing by suppressing inflammation and promoting neovascularization and re-epithelization. Meanwhile, the infusion of HPO CM activated the COX₂-PGE₂ axis both in vitro and in vivo. And the upregulation of COX₂ was further dependent on the activation of ErK1/2-MAPK pathway. In addition, vascular endothelial growth factor, tissue inhibitors of metalloproteinases-1, and chemokine (C-C motif) ligand 20 (CCL-20) were analyzed as being highly abundant factors secreted by ADMSCs under hypoxic condition. Notably, the blockade of CCL-20 abrogated the HPO CM-induced COX₂ signaling in the primary gastric mucosal epithelial cells, while incubation with recombinant CCL-20 increased the expression of COX₂. In conclusion, the secretome from hypoxia-conditioned ADMSCs facilitates the repair of gastric mucosal injury through the enhancement of angiogenesis and re-epithelization, as well as the activation of COX₂-PGE₂ axis with a paracrine activity involving CCL-20 factor.

Autologous adipose-derived stem cell sheets enhance the strength of intestinal anastomosis

Objective

Adipose-derived stem cells (ASCs) are capable of multiple differentiation pathways, imparting immunomodulatory effects, and secreting factors that are important for wound healing. These characteristics can be exploited to decrease the incidence of anastomotic leakage.

Methods

In order to delay local wound healing at the anastomotic site, we induced ischemia in a portion of porcine small intestine by ligating vessels. Then, we injected mitomycin C into the serosa of the small intestine above the ligated vessels. Anastomotic sites were created by 2 cm incisions made in the opposite mesenteric area. ASCs were isolated from the porcine subcutaneous fat tissues and expanded under culture conditions. ASCs were trypsinized and seeded on temperature-responsive dishes and cultured to form confluent sheets. Three ASC sheets were transplanted onto the serous membrane after suturing. The extent of anastomotic wound healing was evaluated by bursting pressure, hydroxyproline content, and mRNA expression of collagen-1 alpha1 and collagen-3 alpha1.

Results

We found that transplantation of ASC sheets increased anastomotic site bursting pressure. Additionally, transplantation of ASC sheets increased the hydroxyproline content of the anastomoses. Furthermore, transplantation of ASC sheets increased mRNA expression of collagen-1 alpha1 and collagen-3 alpha1.

Conclusions

Our findings showed that transplantation of autologous ASC sheets enhanced collagen synthesis and anastomotic strength. Further studies are necessary to identify substances that, in combination with ASC sheets, might enhance collagen synthesis and healing in sites of anastomosis.

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Transplantation of adipose-derived stem cell (ASC) sheets after intestinal anastomosis stimulated collagen synthesis and improved anastomotic strength.

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Paracrine effects of the growth factors released by the ASC sheets might contribute to healing at the anastomotic site and stimulate the fibroblast and the collagen synthesis.

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This new approach might be a feasible and promising strategy to prevent anastomotic leakage.

Effects of adipose stem cell sheets on colon anastomotic leakage in an experimental model: Proof of principle

The most dreaded complication of colorectal surgery is anastomotic leakage. Adipose tissue-derived stem cell sheets (ASC sheets) prepared from temperature-responsive culture surfaces can be easily transplanted onto tissues. These sheets are proposed to improve cell transplant efficiency and enhance wound healing. The aim of this study was to investigate whether application of ASC sheets could prevent leakage of sutured colorectal anastomoses. Insufficient suturing of colorectal anastomoses was performed in Wistar rats to create a colorectal anastomotic leakage model. Rats were randomized to ASC sheet application or control group. Leakage, abscess formation, adhesion formation, anastomotic bursting pressure (ABP), and histology were evaluated on postoperative day 3 or 7. ASC sheet application significantly reduced anastomotic leakage compared to controls, without increased adhesion formation. ASC sheet transplantation resulted in more CD3+ T-cells and CD163+ anti-inflammatory macrophages at the anastomotic site than the control group. ABP, vessel density and collagen deposition were not different between groups. Using cell sheet technology, we generated ASC sheets that prevented disruption of sutured colorectal anastomoses as shown by reduced leakage. Increased numbers of anti-inflammatory macrophages and T-cells might have contributed to this positive effect.

Immunomodulatory oligonucleotide IMT504: Effects on mesenchymal stem cells as a first-in-class immunoprotective/immunoregenerative therapy

The immune responses of humans and animals to insults (i.e., infections, traumas, tumoral transformation and radiation) are based on an intricate network of cells and chemical messengers. Abnormally high inflammation immediately after insult or abnormally prolonged pro-inflammatory stimuli bringing about chronic inflammation can lead to life-threatening or severely debilitating diseases. Mesenchymal stem cell (MSC) transplant has proved to be an effective therapy in preclinical studies which evaluated a vast diversity of inflammatory conditions. MSCs lead to resolution of inflammation, preparation for regeneration and actual regeneration, and then ultimate return to normal baseline or homeostasis. However, in clinical trials of transplanted MSCs, the expectations of great medical benefit have not yet been fulfilled. As a practical alternative to MSC transplant, a synthetic drug with the capacity to boost endogenous MSC expansion and/or activation may also be effective. Regarding this, IMT504, the prototype of a major class of immunomodulatory oligonucleotides, induces in vivo expansion of MSCs, resulting in a marked improvement in preclinical models of neuropathic pain, osteoporosis, diabetes and sepsis. IMT504 is easily manufactured and has an excellent preclinical safety record. In the small number of patients studied thus far, IMT504 has been well-tolerated, even at very high dosage. Further clinical investigation is necessary to demonstrate the utility of IMT504 for resolution of inflammation and regeneration in a broad array of human diseases that would likely benefit from an immunoprotective/immunoregenerative therapy.

Bradykinin stimulates protein kinase D-mediated colonic myofibroblast migration via cyclooxygenase-2 and heat shock protein 27

BACKGROUND

Inflammatory bowel disease is characterized by episodic intestinal injury and repair. Myofibroblasts are gastrointestinal tract stromal cells that regulate the reparative process and are known targets of inflammatory mediators including bradykinin (BK). However, the mechanisms through which inflammation regulates myofibroblast-induced wound healing remain incompletely understood. Here, we demonstrate, for the first time, that BK stimulates myofibroblast migration through protein kinase D (PKD)-mediated activation of the cyclooxygenase-2 (COX-2) and heat shock protein 27 (Hsp27) pathways.

MATERIALS AND METHODS

CCD-18Co is a human colonic myofibroblast cell line used from passages 8 to 14. An in vitro scratch assay assessed the effect of BK (100 nM) on myofibroblast migration over 24 h in the presence or absence of several inhibitors (CID755673 [10 μM] and NS398 [10 μM]). Hsp27 small interfering RNA evaluated the effect of Hsp27 on colonic myofibroblast migration. Antibodies to pPKD, pHsp27, and COX-2 evaluated expression levels by Western blot.

RESULTS

BK stimulated myofibroblast migration over 24 h. BK also led to rapid and sustained phosphorylation of PKD at Ser-916, rapid phosphorylation of Hsp27 at Ser-82, and increased COX-2 expression over 4 h. BK-mediated COX-2 expression and Hsp27 phosphorylation were both inhibited by the PKD inhibitor CID755673. Similarly, BK-induced myofibroblast migration was significantly inhibited by CID755673 (P < 0.05), by the direct COX-2 inhibitor NS398 (P < 0.05), and by Hsp27 small interfering RNA (P < 0.05).

CONCLUSIONS

BK stimulates myofibroblast migration through PKD-mediated activation of COX-2 and Hsp27. PKD, COX-2, and Hsp27 all appear to regulate myofibroblast cell migration, a stromal population that may play an important role in mucosal healing in the setting of inflammation.

Mesenchymal stromal cell therapy for the treatment of intestinal ischemia: Defining the optimal cell isolate for maximum therapeutic benefit

Intestinal ischemia is a devastating intraabdominal emergency that often necessitates surgical intervention. Mortality rates can be high, and patients who survive often have significant long-term morbidity. The implementation of traditional medical therapies to prevent or treat intestinal ischemia have been sparse over the last decade, and therefore, the use of novel therapies are becoming more prevalent. Cellular therapy using mesenchymal stromal cells is one such treatment modality that is attracting noteworthy attention in the scientific community. Several groups have seen benefit with cellular therapy, but the optimal cell line has not been identified. The purpose of this review is to: 1) Review the mechanism of intestinal ischemia and reperfusion injury, 2) Identify the mechanisms of how cellular therapy may be therapeutic for this disease, and 3) Compare various MSC tissue sources to maximize potential therapeutic efficacy in the treatment of intestinal I/R diseases.

Safety and therapeutic effect of mesenchymal stem cell infusion on moderate to severe ulcerative colitis

One of the primary targets of the clinical treatment of ulcerative colitis (UC) is to repair the damaged colonic mucosa. Mesenchymal stem cells (MSCs) have therapeutic potential in regenerative medicine due to their differentiation capacity and their secretion of numerous bioactive molecules. The present study describes a clinical trial (trial registration no. NCT01221428) investigating the safety and therapeutic effect of MSCs derived from human umbilical cord on moderate to severe UC. Thirty-four patients with UC were included in group I and treated with MSC infusion in addition to the base treatment, and thirty-six patients were in group II and treated with normal saline in addition to the base treatment. One month after therapy, 30/36 patients in group I showed good response, and diffuse and deep ulcer formation and severe inflammatory mucosa were improved markedly. During the follow up, the median Mayo score and histology score in group I were decreased while IBDQ scores were significantly improved compared with before treatment and group II (P<0.05). Compared with group II, there were no evident adverse reactions after MSC infusion in any of the patients in group I, and no chronic side effects or lingering effects appeared during the follow-up period. In conclusion, MSC infusion might be a useful and safe therapy for treating UC.

Potential role of probiotics in the management of gastric ulcer

Gastric ulcer is one of the most common chronic gastrointestinal diseases characterized by a significant defect in the mucosal barrier. Helicobacter pylori (H. pylori) infection and the frequent long-term use of non-steroidal anti-inflammatory drugs are major factors involved in gastric ulcer development. Acid inhibitors and antibiotics are commonly used to treat gastric ulcer. However, in the last few decades, the accumulating evidence for resistance to antibiotics and the side effects of antibiotics and acid inhibitors have drawn attention to the possible use of probiotics in the prevention and treatment of gastric ulcer. Probiotics are live microorganisms that when administered in adequate amounts confer health benefits on the host. Currently, the available experimental and clinical studies indicate that probiotics are promising for future applications in the management of gastric ulcers. This review aims to provide an overview of the general health benefits of probiotics on various systemic and gastrointestinal disorders with a special focus on gastric ulcer and the involved cellular and molecular mechanisms: i) Protection of gastric mucosal barrier; ii) upregulation of prostaglandins, mucus, growth factors and anti-inflammatory cytokines; iii) increased cell proliferation to apoptosis ratio; and iv) induction of angiogenesis. Finally, some of the available data on the possible use of probiotics in H. pylori eradication are discussed.

Effect of TGF-β1 on the Migration and Recruitment of Mesenchymal Stem Cells after Vascular Balloon Injury: Involvement of Matrix Metalloproteinase-14

Restenosis or occlusion after vascular procedures is ascribed to intimal hyperplasia. Transforming growth factor (TGF)-β1 is involved in recruitment of mesenchymal stem cells (MSCs) following arterial injury, and its release from latent TGF-binding protein by matrix metalloproteinase (MMP)-14-induced proteolysis contributes to neointima formation. However, the relationship between MMP-14 and TGF-β1 activation in restenosis is unknown. This study investigated the relationship using a rat model of balloon-induced injury. Rats were assigned to vehicle-, SB431542 (SB)-, or recombinant human (rh)TGF-β1-treated groups and examined at various time points after balloon-induced injury for expression of TGF-β1/Smad signalling pathway components, MMP-14 and MSCs markers including Nestin, CD29, and Sca1⁺CD29⁺CD11b/c⁻CD45⁻. Intimal hyperplasia was reduced in SB- and rhTGF-β1-treated rats. The expression of TGF-β1, TGF-β1RI, and Smad2/3 was decreased, but the levels of phosphorylated Smad2/3 were higher in SB-treated rats than vehicle-treated after 7 days to 14 days. rhTGF-β1 administration decreased the expression of TGF-β1/Smad pathway proteins, except for TGF-β1RI. Nestin and CD29 expression and the number of Sca1⁺CD29⁺CD11b⁻CD45⁻ cells were reduced, whereas MMP-14 expression was increased after SB431542 and rhTGF-β1 administration. These results suggest that TGF-β1/Smad signalling and MMP-14 act to recruit MSCs which differentiate to vascular smooth muscle cells and mesenchymal-like cells that participate in arterial repair/remodelling.

Therapeutic and recurrence-preventing effects of Qi-Replenishing and Blood-Activating Formula in rats with acetic acid-induced gastric ulcer

OBJECTIVE

To explore the therapeutic and recurrence-preventing effects of Qi-Replenishing and Blood-Activating Formula in rats with acetic acid-induced gastric ulcer.

METHODS

A total of 138 SD rats were selected to make rat models with gastric ulcer induced by acetic acid (24 rats with sham operation served as sham operation group), and were randomly divided into model group (n = 30), western medicine group (n = 30), traditional Chinese medicine (TCM) group (n = 24) and combination group (combined western medicine and TCM group, n = 30). Western medicine group was gavaged with omeprazole in the morning and with iso-volumetric distilled water in the afternoon; TCM group and TCM sham operation group were gavaged with iso-volumetric distilled water in the morning and with Qi-Replenishing and Blood-Activating Formula in the afternoon; combination group was gavaged with omeprazole in the morning and with Qi-Replenishing and Blood-Activating Formula in the afternoon; sham operation group and model group were gavaged with iso-volumetric distilled water both in the morning and afternoon. Ulcer indexes and degree of mucosal degree in rats at different time points after gavage were observed. Twenty-eight days after gavage, interleukin (IL)-1β was given to induce ulcer recurrence so as to observe the recurrent severity and rate of ulcer in each group.

RESULTS

Compared with model group and western medicine group, treatment in combination group could prominently reduce the ulcer index of rats with peptic ulcer, and increase the healing rate and inhibition rate of peptic ulcer. After IL-1β-induced ulcer recurrence, combination group was significantly superior to model group and western medicine group in ulcer recurrent rate [50% (3/6) vs. 100% (6/6)] and severity.

CONCLUSIONS

Basic acid-suppression therapy combined with Qi-Replenishing and Blood-Activating Formula can effectually improve the ulcer healing quality and reduce ulcer recurrence.

Are They Really Stem Cells? Scrutinizing the Identity of Cells and the Quality of Reporting in the Use of Adipose Tissue-Derived Stem Cells

There is an increasing concern that the term adipose tissue-derived stem cell (ASC) is inappropriately used to refer to the adipose stromal vascular fraction (SVF). To evaluate the accuracy and quality of reporting, 116 manuscripts on the application of ASC in humans and animals were examined based on the 2013 published International Federation for Adipose Therapeutics and Science (IFATS)/ International Society for Cellular Therapy (ISCT) joint statement and in reference to current guidelines for clinical trials and preclinical studies. It is disconcerting that 4 among the 47 papers or 8.51% (CI 2.37-20.38) surveyed after publication of IFATS/ISCT statement reported using ASCs but in fact they used unexpanded cells. 28/47 or 59.57% (CI 44.27-73.63) explicitly reported that adherent cells were used, 35/47 or 74.47% (CI 59.65-86.06) identified expression of surface markers, and 25/47 or 53.19% (CI 14.72-30.65) verified the multilineage potential of the cells. While there are a number of papers examined in this survey that were not able to provide adequate information on the characteristics of ASCs used with some erroneously referring to the SVF as stem cells, there are more room for improvement in the quality of reporting in the application of ASCs in humans and animals.

Perforated peptic ulcer

Perforated peptic ulcer is a common emergency condition worldwide, with associated mortality rates of up to 30%. A scarcity of high-quality studies about the condition limits the knowledge base for clinical decision making, but a few published randomised trials are available. Although Helicobacter pylori and use of non-steroidal anti-inflammatory drugs are common causes, demographic differences in age, sex, perforation location, and underlying causes exist between countries, and mortality rates also vary. Clinical prediction rules are used, but accuracy varies with study population. Early surgery, either by laparoscopic or open repair, and proper sepsis management are essential for good outcome. Selected patients can be managed non-operatively or with novel endoscopic approaches, but validation of such methods in trials is needed. Quality of care, sepsis care bundles, and postoperative monitoring need further assessment. Adequate trials with low risk of bias are urgently needed to provide better evidence. We summarise the evidence for perforated peptic ulcer management and identify directions for future clinical research.

Application of mesenchymal stem cells in digestive system diseases

Mesenchymal stem cells (MSCs) have the capacity of multipotent differentiation and the property of immunomodulation. MSCs have been widely used in digestive system disease research because of their advantageous characteristics such as homing to areas of inflammation or tumour tissue, anti-inflammation, high plasticity, absence of immunologic rejection, being easy to be isolated, and being convenient for the expression of exogenous genes. In this article, we will review the application of mesenchymal stem cells in digestive system diseases including caustic esophagus injury, reflux esophagitis, gastric ulcer, radioactive intestinal injury, severe acute pancreatitis, inflammatory bowel disease, nonalcoholic steatohepatitis, acute liver failure, hepatic fibrosis, autoimmune liver diseases, liver cirrhosis, esophageal cancer, gastric cancer, colon cancer, liver cancer, and pancreatic cancer.