Oral administration of conditioned medium obtained from mesenchymal stem cell culture prevents subsequent stricture formation after esophageal submucosal dissection in pigs

Anti-fibrogenic effect of umbilical cord-derived mesenchymal stem cell-conditioned media in human esophageal fibroblasts

Esophageal fibrosis can develop due to caustic or radiation injuries. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) are known to mitigate fibrosis in various organs. However, the potential effects of UC-MSCs on human esophageal fibrosis remain underexplored. This study investigated the anti-fibrogenic properties and mechanisms of UC-MSC-derived conditioned media (UC-MSC-CM) on human esophageal fibroblasts (HEFs). HEFs were treated with TGF-β1 and then cultured with UC-MSC-CM, and the expression levels of extracellular matrix (ECM) components, RhoA, myocardin related transcription factor A (MRTF-A), serum response factor (SRF), Yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ) were measured. UC-MSC-CM suppressed TGF-β1-induced fibrogenic activation in HEFs, as evidenced by the downregulation of ECM. UC-MSC-CM diminished the expression of RhoA, MRTF-A, and SRF triggered by TGF-β1. In TGF-β1-stimulated HEFs, UC-MSC-CM decreased the nuclear localization of MRTF-A and YAP. Additionally, UC-MSC-CM diminished the TGF-β1-induced nuclear expressions of YAP and TAZ, while concurrently enhancing the cytoplasmic presence of phosphorylated YAP. Furthermore, UC-MSC-CM reduced TGF-β1-induced phosphorylation of Smad2. These findings suggest that UC-MSC-CM may inhibit TGF-β1-induced fibrogenic activation in HEFs by targeting the Rho-mediated MRTF/SRF and YAP/TAZ pathways, as well as the Smad2 pathway. This indicates its potential as a stem cell therapy for esophageal fibrosis.

Therapeutic effects and potential mechanisms of endoscopic submucosal injection of mesenchymal stem cells on chronic atrophic gastritis

Previous studies have demonstrated the rejuvenating and restorative actions of mesenchymal stem cells (MSCs) in multiple diseases, but their role in reversing chronic atrophic gastritis (CAG) is not well understood owing to their low efficiency in homing to the stomach. In this work, we investigated the therapeutic effect of umbilical cord-derived MSCs (UC-MSCs) on CAG by endoscopic submucosal injection and preliminarily explored possible mechanisms in vitro. MSCs and normal saline (NS) were injected into the submucosa of the stomach in randomly grouped CAG rabbits. Therapeutic effects on serum indices and histopathology of the gastric mucosa were analyzed in vivo at 30 and 60 days after MSCs injection. GES-1 cells were co-cultured with MSCs in vitro using a Transwell system and cell viability, proliferation, and migration ability were detected. Additionally, in view of the potential mechanisms, the relative protein expression levels of apoptosis, autophagy and inflammation in vitro were explored by Western Blotting. We found that submucosal injection of MSCs up-regulated serum indices (G-17, PGI and PGI/PGII) and alleviated histopathological damage to the gastric mucosa in CAG rabbits. Co-culture of GES-1 cells with MSCs improved cell viability, proliferation, and migration ability, while suppressing apoptosis. We also observed a reduction in the expression of apoptosis indicators, including Bax and cleaved caspase-3, in GES-1 cells after co-culture with MSCs in vitro. Our findings suggest that submucosal injection of MSCs is a promising approach for reversing CAG, and attenuating apoptosis plays a potential role in this process.

Application of polyglycolic acid sheets and basic fibroblast growth factor to prevent esophageal stricture after endoscopic submucosal dissection in pigs

BACKGROUND

Endoscopic submucosal dissection (ESD) has been the first-line treatment for early-stage esophageal cancer. However, it often causes postoperative stricture in cases requiring wide dissection. Basic fibroblast growth factor (bFGF) reportedly has anti-scarring effects during cutaneous wound healing. We hypothesized that suppressing myofibroblast activation will prevent stricture after esophageal ESD.

METHODS

We resected a complete porcine esophagus circumference section by ESD. To investigate the preventive effect of bFGF on esophageal stricture formation after ESD, we endoscopically applied bFGF-soaked poly-glycolic acid (PGA) sheets onto the wound bed after ESD and fixed them by spraying fibrin glue (PGA + bFGF group), PGA sheets alone onto the wound bed and fixed them by spraying fibrin glue (PGA group), or nothing (control group). After removing the esophagus on day 22, we evaluated the mucosal constriction rate.

RESULTS

Compared with those in the control group, esophageal stricture was significantly reduced in the PGA + bFGF group, and the areas stained with α-SMA and calponin-1 antibodies were significantly inhibited in the PGA + bFGF and PGA groups. The thickness of the fibrous layer in the PGA + bFGF group was uniform compared to that of the other groups. Thus, PGA + bFGF inhibited the development of unregulated fibroblasts in the acute phase, leading to uniform wound healing.

CONCLUSIONS

Stenosis after esophageal ESD is related to fibrosis in the acute phase. Administration of PGA and bFGF suppresses myofibroblast activation in the acute phase, thereby preventing esophageal constriction in pigs.

Prevention of esophageal stenosis via in situ cross-linkable alginate/gelatin powder in a new submucosal exfoliation model in rats

Endoscopic submucosal dissection (ESD) for the treatment of esophageal mucosal lesions often leads to postoperative stenosis, causing difficulty in swallowing, known as dysphagia. In this study, we developed an in situ cross-linkable powder composed of alginate, gelatin, transglutaminase (TG), and calcium chloride ions (Ca2+), which can be administered through a 1.5 m-long and 3.2 mm-diameter endoscopic instrument channel. The powdered mixture of alginate and gelatin quickly formed a hydrogel by absorbing body fluids and was cross-linked by TG and Ca2+, which adhered ex vivo to porcine submucosal layers for over 2 weeks. In addition, we developed a new submucosal exfoliation model in rats that induced severe stenosis, similar to the ESD-induced stenosis models in clinical practice. When administered to the new rat model, the powder system effectively reduced the severity of esophageal stenosis based on body weight change monitoring, anatomical findings, and histological analysis. The body weight of the rats was maintained at the initial weight on postoperative day 14 (POD14), and epithelialization on POD7 and 14 improved to almost 100%. Additionally, collagen accumulation and the number of α-SMA-positive cells decreased due to powder administration. Therefore, these findings indicate that the in situ cross-linkable powder can prevent esophageal stenosis after ESD.

Endoscopically injectable and self-crosslinkable hydrogel-mediated stem cell transplantation for alleviating esophageal stricture after endoscopic submucosal dissection

Esophageal stricture after extensive endoscopic submucosal dissection impairs the quality of life of patients with superficial esophageal carcinoma. Beyond the limitations of conventional treatments including endoscopic balloon dilatation and the application of oral/topical corticosteroids, several cell therapies have been recently attempted. However, such methods are still limited in clinical situations and existing setups, and the efficacies are less in some cases since the transplanted cells hardly remain at the resection site for a long time due to swallowing and peristalsis of the esophagus. Thus, a cell transplantation platform directly applicable with clinically established equipment and enabling stable retention of transplanted cells can be a promising therapeutic option for better clinical outcomes. Inspired by ascidians that rapidly self-regenerate, this study demonstrates endoscopically injectable and self-crosslinkable hyaluronate that allows both endoscopic injection in a liquid state and self-crosslinking as an in situ-forming scaffold for stem cell therapy. The pre-gel solution may compatibly be applied with endoscopic tubes and needles of small diameters, based on the improved injectability compared to the previously reported endoscopically injectable hydrogel system. The hydrogel can be formed via self-crosslinking under in vivo oxidative environment, while also exhibiting superior biocompatibility. Finally, the mixture containing adipose-derived stem cells and the hydrogel can significantly alleviate esophageal stricture after endoscopic submucosal dissection (75% of circumference, 5 cm in length) in a porcine model through paracrine effects of the stem cell in the hydrogel, which modulate regenerative processes. The stricture rates on Day 21 were 79.5% ± 2.0%, 62.8% ± 1.7%, and 37.9% ± 2.9% in the control, stem cell only, and stem cell-hydrogel groups, respectively (p < 0.05). Therefore, this endoscopically injectable hydrogel-based therapeutic cell delivery system can serve as a promising platform for cell therapies in various clinically relevant situations.

Clinical effectiveness of short course oral prednisone for stricture prevention after semi-circumferential esophageal endoscopic submucosal dissection

Background and study aims  Esophageal strictures (ES) occur frequently after semi-circumferential endoscopic submucosal dissection (ESD) for the eradication of superficial esophageal neoplasms and negatively impact a patient's quality of life. Oral corticosteroids have been shown to be clinically effective, but the most appropriate drug, dose and duration is yet to be determined. The aim of the study was to investigate the clinical effectiveness and safety of 30 mg prednisone with a shortened tapering schedule on ES after semi-circumferential ESD. Patients and methods  This was a retrospective observational study that analyzed consecutive patients with esophageal neoplasms who underwent semi-circumferential ESD with a resection defect greater than 75 % of the circumference that received a protocol of oral steroids for stricture prevention. On postoperative day 3, 30 mg prednisone was prescribed, tapering weekly to 20 mg/10 mg/5 mg over 4 weeks. Follow-up included clinic consultation and endoscopic review at weeks 2 and 4. Effectiveness outcomes included ES rates, safety, tolerability, resection, dilatation and recurrence rates. Results  Ninety ESD procedures were carried out during the specified time period and 18 patients met the inclusion criteria for the final analysis. The mean age was 61.5 years, lesion size was 52.5 mm, and final histology was squamous cell carcinoma in all patients. Incidence of intra-procedure complications was: bleeding 5.5 % (1/18) and ES 5.5 % (1/18), requiring a median two endoscopic dilatations. En bloc, R0 and curative resection rates were 88.8 %, 72.2 %, and 55.5 %, respectively. Conclusions  The short tapering schedule of 30 mg oral prednisone is clinically efficacious and safe for prevention of ES after semi-circumferential ESD in Latin American patients.

Potential stem cell-Conditioned medium and their derived exosomes versus omeprazole in treatment of experimental model of gastric ulcer

Gastric ulcer is a common frequent clinical problem affecting all age and gender. This work aims to compare between the therapeutic effects of stem cell derived exosomes, stem cells conditioned medium and omeprazole on the healing of gastric ulcer model. Fifty rats were, assigned into 5 groups; control, gastric ulcer, omeprazole-treated, conditioned medium- treated, and exosomes-treated groups. Gastric ulcer was induced by aspirin dissolved in 1% carboxymethyl cellulose at a daily dose of 200 mg/kg for 5 consecutive days. Stomach specimens were obtained for histological, biochemical, and immunohistochemical assessments. The gastric ulcer group revealed widening of the fundic glands lumen containing, exfoliated dead cells. There was a remarkable distortion of the normal histological structure of the gastric mucosa with surface lining epithelial cell sloughing, vascular congestion and inflammatory cell infiltration. Both exosomes and conditioned medium treatments ameliorated almost all of the histopathological changes. Interestingly, the healing effect of exosomes was greater because it restored the histological architecture of gastric mucosa to nearly normal. In conclusion, this work may pave the future for using stem cell derived exosomes as a more convenient and effective adjuvant therapy in gastric ulcer.

A comparison of isolation and culture protocols for human amniotic mesenchymal stem cells

The successful translation of mesenchymal stem cells (MSCs) from bench to bedside is predicated upon their regenerative capabilities and immunomodulatory potential. Many challenges still exist in making MSCs a viable and cost-effective therapeutic option, due in part to the challenges of sourcing MSCs from adult tissues and inconsistencies in the characterization of MSCs. In many cases, adult MSC collection is an invasive procedure, and ethical concerns and age-related heterogeneity further complicate obtaining adult tissue derived MSCs at the scales needed for clinical applications. Alternative adult sources, such as post-partum associated tissues, offer distinct advantages to overcome these challenges. However, successful therapeutic applications rely on the efficient ex-vivo expansion of the stem cells while avoiding any culture-related phenotypic alterations, which requires optimized and standardized isolation, culture, and cell preservation methods. In this review, we have compared the isolation and culture methods for MSCs originating from the human amniotic membrane (hAMSCs) of the placenta to identify the elements that support the extended subculture potential of hAMSCs without compromising their immune-privileged, pluripotent regenerative potential.Abbreviations:AM: Human amniotic membrane; ASCs: Adipose tissue-derived stem cells; BM-MSCs: Bone marrow-mesenchymal stem cells; DMEM: Dulbecco's modified eagle medium; DT: Doubling time; EMEM: Eagle's modified essential medium; ESCM: Embryonic stem cell markers; ESCs: Embryonic stem cells; hAECs: Human amniotic epithelial cells; hAMSCs: Human amniotic mesenchymal stem cells; HLA: Human leukocyte antigen; HM: Hematopoietic markers; IM: Immunogenicity markers; MHC: Major histocompatibility complex; MSCs: Mesenchymal stem cells; MCSM: Mesenchymal cell surface markers; Nanog: NANOG homeobox; Oct: Octamer binding transcription factor 4; P: Passage; PM: Pluripotency markers; STRO-1: Stromal precursor antigen-1; SCP: Subculture potential; Sox-2: Sry-related HMG box gene 2; SSEA-4: Stage-specific embryonic antigen; TRA: Tumor rejection antigen.

Mesenchymal Stem Cell Injection in Crohn's Disease Strictures: A Phase I-II Clinical Study

BACKGROUND AND AIM

Mesenchymal stem cells [MSCs] have anti-inflammatory and anti-fibrotic properties and could be a potential therapy for Crohn's disease [CD] strictures. In this phase I-II pilot trial, we assessed safety and efficacy of local MSC injection to treat CD strictures.

METHODS

CD patients with a short [less than 5 cm in length] non-passable stricture accessible by ileocolonoscopy were included. Allogenic bone-marrow derived MSCs were injected in the four quadrants of the stricture. Adverse events and clinical scores were evaluated at each follow-up visit and endoscopy and magnetic resonance enterography were performed at baseline, Week [W]12 and W48. The main judgement criterion for efficacy was the complete [defined by the ability to pass the ileocolonoscope] or partial [defined by a diameter increase] resolution of the stricture at W12. Second efficacy criteria included assessment of the stricture at W48 and evolution of clinical scores at W12 and W48.

RESULTS

We performed 11 MSC injections in 10 CD patients [three primary and seven anastomotic strictures; one stricture injected twice]. MSC injections were well tolerated but four hospitalisations for occlusion were reported. At W12, five patients presented a complete or partial resolution of the stricture [two complete and three partial]. Seven patients were re-evaluated at W48 [one dilated, one operated, and one lost to follow-up] and four patients had a complete resolution. The evolution of clinical scores between W0, W12, and W48 was not statistically significant.

CONCLUSIONS

MSCs injection in CD stricture was well tolerated and may offer a benefit.

Stent placement to prevent strictures after esophageal endoscopic submucosal dissection: a systematic review and meta-analysis

Endoscopic submucosal dissection (ESD) is an important method for the treatment of early esophageal cancer. However, post-procedure stenosis is one of the most common long-term complications. This meta-analysis aimed to investigate whether stent placement is effective in the stenosis prevention, and which type of stent would be more effective. A systematic and electronic search of clinical trials and observational studies conducted before March 2020 on the efficacy of stent placement in preventing esophageal stricture after ESD was performed. Search terms included "ESD," "esophageal stenosis," "esophageal stricture," and "stents." We conducted a bias risk assessment of the eligible reports and a meta-analysis of the data using Revman 5.3 software. We included two randomized controlled trials (RCTs) and a prospective cohort study involving 163 patients with esophageal mucosal defects encompassing at least three-quarters of the esophagus circumference after ESD. The meta-analysis results showed that post-ESD stenosis rates (RR, 0.37; 95% CI, 0.22-0.64; P = 0.0003) and the number of endoscopic balloon dilations (EBDs) (MD, -1.74; 95% CI, -2.46 to -1.01; P < 0.00001) were reduced in the pooled analysis of three studies, indicating that stent placement was effective for stenosis prevention, especially a polyglycolic acid (PGA) sheet combined with stent placement can prevent stenosis (RR, 0.41; 95% CI, 0.23-0.74; P = 0.003) and reduce the number of EBDs (MD, -1.65; 95% CI, -2.40 to -0.90; P < 0.0001) significantly. Stent placement can reduce the rate of esophageal stenosis after ESD, especially when stents are covered with PGA sheets. However, more high-quality, low-bias RCTs with a sufficient sample size are needed to demonstrate its effectiveness.

Topical Application of Conditioned Medium from Hypoxically Cultured Amnion-Derived Mesenchymal Stem Cells Promotes Wound Healing in Diabetic Mice

BACKGROUND

Mesenchymal stem cells or their conditioned medium improve chronic wound healing, and their effect is enhanced by hypoxia. Diabetic foot ulcers are chronic wounds characterized by abnormal and delayed healing, which frequently require amputation. The authors evaluated the effect of topical application of conditioned medium from hypoxically cultured amnion-derived mesenchymal stem cells on wound healing in diabetic mice.

METHODS

Amnion-derived mesenchymal stem cells were cultured under 21% oxygen to prepare normoxic conditioned medium and under 1% oxygen to prepare hypoxic conditioned medium. Hydrogels containing standard medium, normoxic conditioned medium, or hypoxic conditioned medium were topically applied to excisional wounds of mice with streptozotocin-induced diabetes. Ulcer tissues were harvested on day 9; immunohistochemical and quantitative polymerase chain reaction analyses were performed to analyze angiogenesis, inflammatory cell infiltration, and expression levels of inflammation-related genes.

RESULTS

Hypoxic conditioned medium significantly enhanced wound closure, increased capillary density and epithelization, and reduced macrophage infiltration. It also tended to reduce the infiltration of neutrophils and enhance the infiltration of regulatory T cells; it showed a tendency to downregulate the expression of the inflammation-related genes interleukin-1β, interleukin-6, chemokine ligand 1, and chemokine ligand 2. Normoxic conditioned medium exhibited similar effects, although they were of lesser magnitude than those of hypoxic conditioned medium.

CONCLUSIONS

Hydrogels containing hypoxically cultured, amnion-derived mesenchymal stem cell conditioned medium accelerated wound healing in diabetic mice by enhancing angiogenesis, accelerating epithelization, and suppressing inflammation. Therefore, topical application of amnion mesenchymal stem cell-derived hypoxic conditioned medium could be a novel treatment for diabetic foot ulcers.

Biological testing of chitosan-collagen-based porous scaffolds loaded with PLGA/Triamcinolone microspheres for ameliorating endoscopic dissection-related stenosis in oesophagus

Objectives

Endoscopic submucosal dissection (ESD), a preferential approach for early oesophageal neoplasms, inevitably results in oesophageal strictures in patients. Clinical use of glucocorticoids through submucosal injection is beneficial for inhibiting oesophageal stricture following injury; however, it also has limitations, such as dose loss and perforation. Hence, alternatives to glucocorticoid therapy should be developed.

Methods

A novel porous composite scaffold, ChCo‐TAMS, composed of chitosan, collagen‐I and triamcinolone acetonide (TA) loaded into poly (lactic‐co‐glycolic) acid (PLGA) microspheres (TAMS), was successfully constructed and subjected to biological testing to ameliorate oesophageal ESD‐related stenosis.

Results

The synthesized biomaterials displayed unique properties in inhibiting the activation of macrophages, chemokine‐mediated cell recruitment and fibrogenesis of fibroblasts. Further application of the scaffolds in the rat dermal defect and porcine oesophageal ESD model showed that these novel scaffolds played a robust role in inhibiting wound contracture and oesophageal ESD strictures.

Conclusions

The developed composite scaffolds provide a promising clinical medical device for the prevention of post‐operative oesophageal stricture.

Progress of esophageal stricture prevention after endoscopic submucosal dissection by regenerative medicine and tissue engineering

Endoscopic submucosal dissection (ESD) has been widely accepted as an effective treatment for early esophageal cancer. However, post-ESD esophageal stricture remains a thorny issue. We herein review many strategies for preventing post-ESD esophageal stricture, as well as discuss their strengths and weaknesses. These strategies include pharmacological prophylaxis, esophageal stent and tissue engineering and regenerative medicine treatment. In this review, we summarize these studies and discuss the underlying progress and future directions of tissue engineering and regenerative medicine treatment.

Prevention of Stricture after Endoscopic Submucosal Dissection for Superficial Esophageal Cancer: A Review of the Literature

Endoscopic resection has been the standard treatment for intramucosal esophageal cancers (ECs) because of the low risk of lymph node metastases in the lesions. In recent years, endoscopic submucosal dissection (ESD), which can resect large ECs, has been performed. However, the risk of esophageal stricture after ESD is high when the mucosal defect caused by the treatment exceeds 3/4 of the circumference of the lumen. Despite the subsequent high risk of luminal stricture, ESD has been performed even in cases of circumferential EC. In such cases, it is necessary to take measures to prevent stricture. Therefore, in this review, we aimed to clarify the current status of stricture prevention methods after esophageal ESD based on previous literature. Although various prophylactic methods have been reported to have stricture-preventing effects, steroid injection therapy and oral steroid administration are mainstream. However, in cases of circumferential EC, both steroid injection therapy and oral steroid administration cannot effectively prevent luminal stricture. To solve this issue, clinical applications, such as tissue shielding methods with polyglycolic acid sheet, autologous oral mucosal epithelial sheet transplantation, and stent placement, have been developed. However, effective prophylaxis of post-ESD mucosal defects of the esophagus is still unclear. Therefore, further studies in this research field are needed.

Advances in the Prevention and Treatment of Esophageal Stricture after Endoscopic Submucosal Dissection of Early Esophageal Cancer

Endoscopic submucosal dissection (ESD) has become the main treatment for early esophageal cancer. While treating the disease, ESD may also cause postoperative esophageal stricture, which is a global issue that needs resolution. Various methods have been applied to resolve the problem, such as mechanical dilatation, glucocorticoids, anti-scarring drugs, and regenerative medicine; however, no standard treatment regimen exists. This article describes and evaluates the strengths and limitations of new and promising potential strategies for the treatment and prevention of esophageal strictures.

Strategies for treating oesophageal diseases with stem cells

There is a wide range of oesophageal diseases, the most general of which are inflammation, injury and tumours, and treatment methods are constantly being developed and updated. With an increasingly comprehensive understanding of stem cells and their characteristics of multilineage differentiation, self-renewal and homing as well as the combination of stem cells with regenerative medicine, tissue engineering and gene therapy, stem cells are playing an important role in the treatment of a variety of diseases. Mesenchymal stem cells have many advantages and are most commonly applied; however, most of these applications have been in experimental studies, with few related clinical trials for comparison. Therefore, the methods, positive significance and limitations of stem cells in the treatment of oesophageal diseases remain incompletely understood. Thus, the purpose of this paper is to review the current literature and summarize the efficacy of stem cells in the treatment of oesophageal diseases, including oesophageal ulceration, acute radiation-induced oesophageal injury, corrosive oesophageal injury, oesophageal stricture formation after endoscopic submucosal dissection and oesophageal reconstruction, as well as gene therapy for oesophageal cancer.

Lesion size and circumferential range identified as independent risk factors for esophageal stricture after endoscopic submucosal dissection

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is used to treat early esophageal cancer and precancerous lesions. Patients undergoing ESD are prone to esophageal stenosis, which impairs therapeutic efficacy and quality of life. This retrospective study aimed to investigate the potential association between patient demographics and esophageal lesion characteristics with the risk of esophageal stenosis following ESD.

METHODS

For this retrospective study 190 consecutive patients who underwent ESD between January 2013 and January 2015 were recruited. Data on patient demographics, esophageal lesion-related factors, operation details, esophageal stenosis occurrence and measures taken to prevent or treat stricture were collected, and the normality of distribution of each indicator was assessed with a Kolmogorov-Smirnov test. Stenosis risk factors were then identified using univariate and multivariate logistic regression.

RESULTS

Post-ESD esophageal stenosis occurred in 51 cases. Multivariate logistic regression analysis was performed to identify independent risk factors. A history of EMR/ESD (OR = 4.185, 95% CI: 1.511-11.589), resection circumferential diameter (OR = 1.721, 95% CI: 1.135-2.610), non-en bloc resection (OR = 7.413, 95% CI: 2.398-22.921), submucosal infiltration (OR = 3.449, 95% CI: 1.014-11.734) and circumferential resection range (OR = 57.493, 95% CI: 17.236-191.782) were identified as independent risk factors for post-ESD esophageal stenosis. Spraying porcine fibrin adhesive on the resection bed reduced neither the incidence of postoperative stenosis nor the extent of postoperative dilation.

CONCLUSION

Post-ESD esophageal stenosis is significantly related to size and circumferential range of lesion resection. EMR/ESD history, non-en bloc resection and submucosal infiltration may be additional risk factors.

Umbilical cord/placenta-derived mesenchymal stem cells inhibit fibrogenic activation in human intestinal myofibroblasts via inhibition of myocardin-related transcription factor A

Background

The lack of anti-fibrotic agents targeting intestinal fibrosis is a large unmet need in inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis. Previous studies have found that perinatal tissue (umbilical cord, UC; placenta, PL)-derived mesenchymal stem cells (MSCs) reduce fibrosis in several organs. However, their effects on human intestinal fibrosis are poorly understood. This study investigated the anti-fibrogenic properties and mechanisms of MSCs derived from UC and PL (UC/PL-MSCs) on human primary intestinal myofibroblasts (HIMFs).

Methods

The HIMFs were treated with TGF-β1 and co-cultured with UC/PL-MSCs. We used a small molecular inhibitor CCG-100602 to examine whether serum response factor (SRF) and its transcriptional cofactor myocardin-related transcription factor A (MRTF-A) are involved in TGF-β1-induced fibrogenic activation in HIMFs. The anti-fibrogenic mechanism of UC/PL-MSCs on HIMFs was analyzed by detecting the expression of RhoA, MRTF-A, and SRF in HIMFs.

Results

UC/PL-MSCs reduced TGF-β1-induced procollagen1A1, fibronectin, and α-smooth muscle actin expression in HIMFs. This anti-fibrogenic effect was more apparent in the UC-MSCs. TGF-β1 stimulation increased the expressions of RhoA, MRTF-A, and SRF in the HIMFs. TGF-β1 induced the synthesis of procollagen1A1, fibronectin, and α-smooth muscle actin through a MRTF-A/SRF-dependent mechanism. Co-culture with the UC/PL-MSCs downregulated fibrogenesis by inhibition of RhoA, MRTF-A, and SRF expression.

Conclusions

UC/PL-MSCs suppress TGF-β1-induced fibrogenic activation in HIMFs by blocking the Rho/MRTF/SRF pathway and could be considered as a novel candidate for stem cell-based therapy of intestinal fibrosis.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1385-8) contains supplementary material, which is available to authorized users.

Prevention of esophageal stricture after endoscopic resection

Stricture formation after esophageal endoscopic resection has a negative impact on patients' quality of life because it causes dysphagia and requires multiple endoscopic dilations. Various methods by which to prevent stricture have recently been developed and reported. Among these methods, local steroid injection is the most commonly used and is currently considered the standard method for noncircumferential resection. However, local steroid injection has a limited effect on circumferential resection. Thus, oral steroid administration is used for such cases because it may have a stronger effect than local injection. Steroid treatment, both by local injection and oral administration, is effective and low-cost; however, it may cause fragility of the esophageal wall, resulting in adverse events such as perforation during balloon dilatation. Many innovative approaches have been developed, such as tissue-shielding methods with polyglycolic acid, tissue engineering approaches with autologous oral mucosal epithelial cell sheet transplantation, and stent insertion. These methods may be promising, but they are limited by a scarcity of data. Further investigations are needed to confirm the efficacy of these methods.

Extracellular Vesicles from Amnion-Derived Mesenchymal Stem Cells Ameliorate Hepatic Inflammation and Fibrosis in Rats

Background

There are no approved drug treatments for liver fibrosis and nonalcoholic steatohepatitis (NASH), an advanced stage of fibrosis which has rapidly become a major cause of cirrhosis. Therefore, development of anti-inflammatory and antifibrotic therapies is desired. Mesenchymal stem cell- (MSC-) based therapy, which has been extensively investigated in regenerative medicine for various organs, can reportedly achieve therapeutic effect in NASH via paracrine action. Extracellular vesicles (EVs) encompass a variety of vesicles released by cells that fulfill functions similar to those of MSCs. We herein investigated the therapeutic effects of EVs from amnion-derived MSCs (AMSCs) in rats with NASH and liver fibrosis.

Methods

NASH was induced by a 4-week high-fat diet (HFD), and liver fibrosis was induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl₄) twice a week for six weeks. AMSC-EVs were intravenously injected at weeks 3 and 4 in rats with NASH (15 μg/kg) and at week 3 in rats with liver fibrosis (20 μg/kg). The extent of inflammation and fibrosis was evaluated with quantitative reverse transcription polymerase chain reaction and immunohistochemistry. The effect of AMSC-EVs on inflammatory and fibrogenic response was investigated in vitro.

Results

AMSC-EVs significantly decreased the number of Kupffer cells (KCs) in the liver of rats with NASH and the mRNA expression levels of inflammatory cytokines such as tumor necrosis factor- (Tnf-) α, interleukin- (Il-) 1β and Il-6, and transforming growth factor- (Tgf-) β. Furthermore, AMSC-EVs significantly decreased fiber accumulation, KC number, and hepatic stellate cell (HSC) activation in rats with liver fibrosis. In vitro, AMSC-EVs significantly inhibited KC and HSC activation and suppressed the lipopolysaccharide (LPS)/toll-like receptor 4 (TLR4) signaling pathway.

Conclusions

AMSC-EVs ameliorated inflammation and fibrogenesis in a rat model of NASH and liver fibrosis, potentially by attenuating HSC and KC activation. AMSC-EV administration should be considered as a new therapeutic strategy for chronic liver disease.

Evaluation of amnion-derived mesenchymal stem cells for treatment-resistant moderate Crohn's disease: study protocol for a phase I/II, dual-centre, open-label, uncontrolled, dose-response trial

Introduction

The medical treatment options for patients with Crohn’s disease (CD) are limited and patients resistant to those therapies are left requiring surgical operations that usually only achieve some symptomatic relief. Mesenchymal stem cells (MSC) have been shown to be effective for the treatment of CD, and we have demonstrated in animal experiments that human amnion-derived MSCs (AMSC) are a potential new therapeutic strategy. Therefore, we designed this study to investigate the safety and efficacy of AMSCs in patients with treatment-resistant CD.

Methods and analysis

This is the protocol for an ongoing phase I/II, dual-centre, open-label, uncontrolled, dose–response study. The estimated enrolment is 6–12 patients with treatment-resistant, moderate CD. A dose of 1.0×10⁶ cells/kg will be administered intravenously in the low-dose group at days 0 and 7. After confirming the safety of low-dose administration, a dose of 4.0×10⁶ cells/kg will be administered intravenously in the high-dose group on days 0 and 7. The primary endpoint will measure the occurrence of adverse events related to acute infusion toxicity, and secondary endpoints will include long-term adverse events and efficacy of AMSC administration.

Ethics and dissemination

The Institutional Review Board of Hokkaido University Hospital approved this study protocol (approval number H29-6). A report releasing study results will be submitted to an appropriate journal.

Discussion

This study is the first to investigate the safety and efficacy of AMSC use for CD treatment. Our results will advance studies on more efficient and convenient methods to overcome the limits of available CD treatments.

Trial registration number

UMIN000029841.

Progress on the Prevention of Esophageal Stricture after Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) has been widely accepted as an effective, minimally invasive treatment for superficial esophageal cancers. However, esophageal stricture often occurs in patients with large mucosal defects after ESD. In this review, we discuss various approaches recently researched to prevent esophageal strictures after ESD. These approaches can be classified as pharmacological treatments, esophageal stent treatments, and tissue engineering approaches. Most of the preventive approaches still have their limitations and require further research. With the improvement of current therapies, ESD can be more widely utilized as a minimally invasive treatment with minimal complications.

Mesenchymal stem cell therapy for acute and chronic pancreatitis

Mesenchymal stem cells (MSCs) have attracted attention as a cell source for regenerative medicine. In particular, MSCs have an anti-inflammatory effect by secreting several kinds of bioactive molecules. MSC therapy is now being applied to various gastrointestinal diseases, such as graft-versus-host disease, inflammatory bowel disease, and liver cirrhosis. Therefore, MSC therapy has the potential to be a novel treatment for acute and chronic pancreatitis by suppressing inflammation. Several studies have investigated the effect of MSC therapy on acute and chronic pancreatitis, but the underlying mechanisms remain unknown. In this review, we summarize the present status of MSC therapy for acute and chronic pancreatitis.

Mesenchymal stem cell transplantation for treatment of pancreatitis

Mesenchymal stem cells (MSCs) are one of the main cell resources of regenerative medicine. Recently, MSCs have been used to treat many diseases, such as Alzheimer's disease, inflammatory bowel disease and cirrhosis, with certain curative effects achieved. MSCs can not only secrete a variety of anti-inflammatory cytokines, but also reduce the secretion of inflammatory factors. Therefore, acute pancreatitis (AP) and chronic pancreatitis (CP) can be treated with MSCs. Several studies have investigated the effect of MSC therapy on acute and CP. MSCs exert a therapeutic effect on AP perhaps via two pathways: anti-inflammatory pathway and anti-apoptotic pathway. However, the mechanism for the therapeutic effect of MSCs on CP is unclear. In this review, we will summarize the progress in MSC treatment of AP and CP.